Bump version

Previously we were just returning the current tile. However, if someone
was holding a reference to this inventory (such as a GUI), then it'd be
outdated and invalid once the turtle had moved.

This caused a couple of issues:
 - turtle_inventory events would not be fired when moving items in the
   turtle GUI.
 - As of 75e2845c01, turtles would no
   longer share their inventory state after moving. Thus, removing items
   from a GUI using an invalid inventory would move them from an old
   tile, duplicating the items.

Fixes #298, fixes #300

.github/ISSUE_TEMPLATE/bug_report.md

@@ -1,16 +1,15 @@
 ---
 name: Bug report
 about: Report some misbehaviour in the mod
-
+labels: bug
 ---
 
 <!--
 ## Before reporting
- - Search for the bug both here and [on the ComputerCraft issues page](https://github.com/dan200/ComputerCraft/issues?utf8=%E2%9C%93&q=is%3Aissue+)
- - If possible, try to reproduce on vanilla ComputerCraft. If it still occurs, [report on the ComputerCraft repo](https://github.com/dan200/ComputerCraft/issues/new) instead.
+ - Search for the bug on the issue tracker. Make sure to look at closed issues too!
 -->
 
 ## Useful information to include:
  - Minecraft version
  - CC: Tweaked version
- - Detailed reproduction steps!** Sometimes I can spot a bug pretty easily, but often it's much more obscure. Anything you can give which will help reproduce it means it'll get fixed quicker.
+ - Detailed reproduction steps: sometimes I can spot a bug pretty easily, but often it's much more obscure. The more information I have to help reproduce it, the quicker it'll get fixed.

.github/ISSUE_TEMPLATE/feature_request.md

@@ -1,15 +1,14 @@
 ---
 name: Feature request
 about: Suggest an idea or improvement
-
+labels: enhancement
 ---
 
 <!--
 ## Before reporting
- - Search for the suggestion both here and [on the ComputerCraft issues page](https://github.com/dan200/ComputerCraft/issues?utf8=%E2%9C%93&q=is%3Aissue+). It's possible someone's suggested it before!
- - Unless something is specific to CC:Tweaked, try to [suggest them on the ComputerCraft repo](https://github.com/dan200/ComputerCraft/issues/new). There's a lot more people watching it, so it allows the wider community to contribute.
+ - Search for the suggestion here. It's possible someone's suggested it before!
 -->
 
 ## Useful information to include:
- - Explanation of how the feature/change chould work.
- - Some rationale/use case for a feature. I'd like to keep CC:T as minimal
+ - Explanation of how the feature/change should work.
+ - Some rationale/use case for a feature. My general approach to designing new features is to ask yourself "what issue are we trying to solve" and _then_ "is this the best way to solve this issue?".

.github/pull_request_template.md

@@ -1,9 +1,3 @@
-<!--
-Unless this feature is specific to CC:Tweaked, try to [target the original ComputerCraft repo](https://github.com/dan200/ComputerCraft/) instead. There's a lot more people watching it, so it allows the wider community to contribute.
--->
-
-## Useful information to include:
- - Brief explanation of the changes you've made.
- - Rationale of why this change has been made/reasoning behind it.
-
-The more information you can provide, the easier it is to review something now _and_ to see why a change was made, when the code needs updating in the future.
+## A quick checklist
+ - If there's a existing issue, please link to it. If not, provide fill out the same information you would in a normal issue - reproduction steps for bugs, rationale for use-case.
+ - If you're working on CraftOS, try to write a few test cases so we can ensure everything continues to work in the future. Tests live in `src/test/resources/test-rom/spec` and can be run with `./gradlew check`.

.github/workflows/main-ci.yml

@@ -0,0 +1,18 @@
+name: Build
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v1
+
+    - name: Set up JDK 1.8
+      uses: actions/setup-java@v1
+      with:
+        java-version: 1.8
+
+    - name: Build with Gradle
+      run: ./gradlew build --no-daemon

.gitignore

@@ -15,3 +15,9 @@
 .idea
 .gradle
 *.DS_Store
+
+.classpath
+.project
+.settings/
+bin/
+*.launch

.luacheckrc

@@ -17,7 +17,8 @@ ignore = {
 -- are largely unsupported.
 include_files = {
     'src/main/resources/assets/computercraft/lua/rom',
-    'src/main/resources/assets/computercraft/lua/bios.lua'
+    'src/main/resources/assets/computercraft/lua/bios.lua',
+    'src/test/resources/test-rom',
 }
 
 files['src/main/resources/assets/computercraft/lua/bios.lua'] = {

.travis.yml

@@ -1,14 +0,0 @@
-language: java
-
-script: ./gradlew build --no-daemon
-
-before_cache:
-  - rm -f  $HOME/.gradle/caches/modules-2/modules-2.lock
-  - rm -fr $HOME/.gradle/caches/*/plugin-resolution/
-cache:
-  directories:
-    - $HOME/.gradle/caches/
-    - $HOME/.gradle/wrapper/s
-
-jdk:
-    - oraclejdk8

LICENSE-luaj

@@ -1,19 +0,0 @@
-Copyright (c) 2007 LuaJ. All rights reserved.
-
-Permission is hereby granted, free of charge, to any person obtaining a copy
-of this software and associated documentation files (the "Software"), to deal
-in the Software without restriction, including without limitation the rights
-to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-copies of the Software, and to permit persons to whom the Software is
-furnished to do so, subject to the following conditions:
-
-The above copyright notice and this permission notice shall be included in
-all copies or substantial portions of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-THE SOFTWARE.

README.md

@@ -1,35 +1,35 @@
 # ![CC: Tweaked](logo.png)
-[![Build Status](https://travis-ci.org/SquidDev-CC/CC-Tweaked.svg?branch=master)](https://travis-ci.org/SquidDev-CC/CC-Tweaked)
+[![Current build status](https://github.com/SquidDev-CC/CC-Tweaked/workflows/Build/badge.svg)](https://github.com/SquidDev-CC/CC-Tweaked/actions "Current build status") [![Download CC: Tweaked on CurseForge](http://cf.way2muchnoise.eu/title/cc-tweaked.svg)](https://minecraft.curseforge.com/projects/cc-tweaked "Download CC: Tweaked on CurseForge")
 
-CC: Tweaked is a fork of ComputerCraft which aims to provide earlier access to the more experimental and in-development
-features of the mod. For a more stable experience, I recommend checking out the
-[original mod](https://github.com/dan200/ComputerCraft).
+CC: Tweaked is a fork of [ComputerCraft](https://github.com/dan200/ComputerCraft), adding programmable computers,
+turtles and more to Minecraft.
 
 ## What?
-CC: Tweaked (or CC:T for short) does not aim to create a competing fork of ComputerCraft, nor am I planning to take it
-in in a vastly different direction to the original mod. In fact, CC:T aims to be a nurturing ground for various
-features, with a pull request against the original mod being the end goal.
+ComputerCraft has always held a fond place in my heart: it's the mod which really got me into Minecraft, and it's the
+mod which has kept me playing it for many years. However, development of the original mod has slowed, as the original
+developers have had less time to work on the mod, and moved onto other projects and commitments.
 
-CC:T also includes many pull requests from the community which have not yet been merged, offering a large number
-of additional bug fixes and features over the original mod.
+CC: Tweaked (or CC:T for short) is an attempt to continue ComputerCraft's legacy. It's not intended to be a competitor
+to CC, nor do I want to take it in a vastly different direction to the original mod. Instead, CC:T focuses on making the
+ComputerCraft experience as _solid_ as possible, ironing out any wrinkles that may have developed over time.
 
 ## Features
-CC: Tweaked contains all the features of the latest alpha, as well as numerous fixes, performance improvements and
-several additional features. I'd recommend checking out [the releases page](https://github.com/SquidDev-CC/CC-Tweaked/releases)
-to see the full changes, but here's a couple of the more interesting changes:
+CC: Tweaked contains all the features of the latest version of ComputerCraft, as well as numerous fixes, performance
+improvements and several nifty additions. I'd recommend checking out [the releases page](https://github.com/SquidDev-CC/CC-Tweaked/releases)
+to see the full set of changes, but here's a couple of the more interesting additions:
 
- - Replace LuaJ with Cobalt.
- - Allow running multiple computers at the same time.
- - Websocket support in the HTTP library.
- - Wired modems and cables act more like multiparts.
- - Add map-like rendering for pocket computers and printed pages/books.
- - Adds the `/computercraft` command, offering various diagnostic tools for server owners. This allows operators to
-   track which computers are hogging resources, turn on and shutdown multiple computers at once and interact with
-   computers remotely.
- - Add full-block wired modems, allowing one to wrap non-solid peripherals (such as turtles, or chests if Plethora is
+ - Improvements to the `http` library, including websockets, support for other HTTP methods (`PUT`, `DELETE`, etc...)
+   and configurable limits on HTTP usage.
+ - Full-block wired modems, allowing one to wrap non-solid peripherals (such as turtles, or chests if Plethora is
    installed).
- - Extended binary file handles. They support file seeking, and reading new lines, allowing full (and accurate)
-   emulation of the standard Lua `io` library.
+ - Pocket computers can be held like maps, allowing you to view the screen without entering a GUI.
+ - Printed pages and books can be placed in item frames and held like maps.
+ - Several profiling and administration tools for server owners, via the `/computercraft` command. This allows operators
+   to track which computers are hogging resources, turn on and shutdown multiple computers at once and interact with
+   computers remotely.
+ - Closer emulation of standard Lua, adding the `debug` and `io` libraries. This also enables seeking within binary
+   files, meaning you don't need to read large files into memory.
+ - Allow running multiple computers on multiple threads, reducing latency on worlds with many computers.
 
 ## Relation to CCTweaks?
 This mod has nothing to do with CCTweaks, though there is no denying the name is a throwback to it. That being said,
@@ -37,13 +37,39 @@ several features have been included, such as full block modems, the Cobalt runti
 computers.
 
 ## Contributing
-Any contribution is welcome, be that using the mod, reporting bugs or contributing code. If you do wish to contribute
-code, do consider submitting it to the ComputerCraft repository first.
-
-That being said, in order to start helping develop CC:T, you'll need to follow these steps:
+Any contribution is welcome, be that using the mod, reporting bugs or contributing code. In order to start helping
+develop CC:T, you'll need to follow these steps:
 
  - **Clone the repository:** `git clone https://github.com/SquidDev-CC/CC-Tweaked.git && cd CC-Tweaked`
  - **Setup Forge:** `./gradlew setupDecompWorkspace`
  - **Test your changes:** `./gradlew runClient` (or run the `GradleStart` class from your IDE).
 
 If you want to run CC:T in a normal Minecraft instance, run `./gradlew build` and copy the `.jar` from `build/libs`.
+
+## Community
+If you need help getting started with CC: Tweaked, want to show off your latest project, or just want to chat about
+ComputerCraft we have a [forum](https://forums.computercraft.cc/) and [Discord guild](https://discord.gg/H2UyJXe)!
+There's also a fairly populated, albeit quiet [IRC channel](http://webchat.esper.net/?channels=#computercraft), if
+that's more your cup of tea.
+
+I'd generally recommend you don't contact me directly (email, DM, etc...) unless absolutely necessary (i.e. in order to
+report exploits). You'll get a far quicker response if you ask the whole community!
+
+## Using
+If you want to depend on CC: Tweaked, we have a maven repo. However, you should be wary that some functionality is only
+exposed by CC:T's API and not vanilla ComputerCraft. If you wish to support all variations of ComputerCraft, I recommend
+using [cc.crzd.me's maven](https://cc.crzd.me/maven/) instead.
+
+```groovy
+dependencies {
+  maven { url 'https://squiddev.cc/maven/' }
+}
+
+dependencies {
+  implementation "org.squiddev:cc-tweaked-${mc_version}:${cct_version}"
+}
+```
+
+You should also be careful to only use classes within the `dan200.computercraft.api` package. Non-API classes are
+subject to change at any point. If you depend on functionality outside the API, file an issue, and we can look into
+exposing more features.

build.gradle

@@ -5,17 +5,22 @@ buildscript {
         jcenter()
         maven {
             name = "forge"
-            url = "http://files.minecraftforge.net/maven"
+            url = "https://files.minecraftforge.net/maven"
         }
     }
     dependencies {
+        classpath 'com.google.code.gson:gson:2.8.1'
         classpath 'net.minecraftforge.gradle:ForgeGradle:2.3-SNAPSHOT'
-        classpath 'org.ajoberstar:gradle-git:1.6.0'
+        classpath 'net.sf.proguard:proguard-gradle:6.1.0beta1'
+        classpath 'org.ajoberstar.grgit:grgit-gradle:3.0.0'
     }
 }
 
 plugins {
-    id 'com.matthewprenger.cursegradle' version '1.0.10'
+    id "checkstyle"
+    id "com.github.hierynomus.license" version "0.15.0"
+    id "com.matthewprenger.cursegradle" version "1.3.0"
+    id "com.github.breadmoirai.github-release" version "2.2.4"
 }
 
 apply plugin: 'net.minecraftforge.gradle.forge'
@@ -23,35 +28,37 @@ apply plugin: 'org.ajoberstar.grgit'
 apply plugin: 'maven-publish'
 apply plugin: 'maven'
 
-version = "1.80pr1.13"
+version = mod_version
+
 group = "org.squiddev"
-archivesBaseName = "cc-tweaked"
+archivesBaseName = "cc-tweaked-${mc_version}"
 
 minecraft {
-    version = "1.12.2-14.23.4.2749"
+    version = "${mc_version}-${forge_version}"
     runDir = "run"
-    replace '${version}', project.version
+    replace '${version}', mod_version
 
-    // the mappings can be changed at any time, and must be in the following format.
-    // snapshot_YYYYMMDD   snapshot are built nightly.
-    // stable_#            stables are built at the discretion of the MCP team.
-    // Use non-default mappings at your own risk. they may not allways work.
-    // simply re-run your setup task after changing the mappings to update your workspace.
-    mappings = "snapshot_20180724"
-    // makeObfSourceJar = false // an Srg named sources jar is made by default. uncomment this to disable.
+    mappings = mappings_version
+    makeObfSourceJar = false
 }
 
 repositories {
     maven {
-        name = "JEI"
-        url  = "http://dvs1.progwml6.com/files/maven"
+        name "JEI"
+        url "https://dvs1.progwml6.com/files/maven"
     }
     maven {
-        name = "squiddev"
-        url = "https://dl.bintray.com/squiddev/maven"
+        name "SquidDev"
+        url "https://squiddev.cc/maven"
+    }
+    ivy {
+        name "Charset"
+        artifactPattern "https://asie.pl/files/mods/Charset/LibOnly/[module]-[revision](-[classifier]).[ext]"
+    }
+    maven {
+        name "Amadornes"
+        url "https://maven.amadornes.com/"
     }
-
-    ivy { artifactPattern "https://asie.pl/files/mods/Charset/LibOnly/[module]-[revision](-[classifier]).[ext]" }
 }
 
 configurations {
@@ -61,18 +68,24 @@ configurations {
 }
 
 dependencies {
-    deobfProvided "mezz.jei:jei_1.12.2:4.8.5.159:api"
+    checkstyle "com.puppycrawl.tools:checkstyle:8.21"
+
+    deobfProvided "mezz.jei:jei_1.12.2:4.15.0.269:api"
     deobfProvided "pl.asie:Charset-Lib:0.5.4.6"
+    deobfProvided "MCMultiPart2:MCMultiPart:2.5.3"
 
-    runtime "mezz.jei:jei_1.12.2:4.8.5.159"
+    runtime "mezz.jei:jei_1.12.2:4.15.0.269"
 
-    shade 'org.squiddev:Cobalt:0.4.0'
+    shade 'org.squiddev:Cobalt:0.5.0-SNAPSHOT'
 
-    testCompile 'junit:junit:4.11'
+    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.4.2'
+    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.4.2'
 
     deployerJars "org.apache.maven.wagon:wagon-ssh:3.0.0"
 }
 
+// Compile tasks
+
 javadoc {
     include "dan200/computercraft/api/**/*.java"
 }
@@ -84,39 +97,101 @@ jar {
         attributes('FMLAT': 'computercraft_at.cfg')
     }
 
-    into("docs", { from (javadoc.destinationDir) })
-
-    into("api", { from (sourceSets.main.allSource) {
+    from (sourceSets.main.allSource) {
         include "dan200/computercraft/api/**/*.java"
-    }})
+    }
 
     from configurations.shade.collect { it.isDirectory() ? it : zipTree(it) }
 }
 
+[compileJava, compileTestJava].forEach {
+    it.configure {
+        options.compilerArgs << "-Xlint" << "-Xlint:-processing" << "-Werror"
+    }
+}
+
+
+
+import java.nio.charset.StandardCharsets
+import java.nio.file.*
+import java.util.zip.*
+
+import com.google.gson.GsonBuilder
+import com.google.gson.JsonElement
+import com.hierynomus.gradle.license.tasks.LicenseCheck
+import com.hierynomus.gradle.license.tasks.LicenseFormat
 import org.ajoberstar.grgit.Grgit
+import proguard.gradle.ProGuardTask
+
+task proguard(type: ProGuardTask, dependsOn: jar) {
+    description "Removes unused shadowed classes from the jar"
+    group "compact"
+
+    injars jar.archivePath
+    outjars "${jar.archivePath.absolutePath.replace(".jar", "")}-min.jar"
+
+    // Add the main runtime jar and all non-shadowed dependencies
+    libraryjars "${System.getProperty('java.home')}/lib/rt.jar"
+    doFirst {
+        sourceSets.main.compileClasspath
+            .filter { !it.name.contains("Cobalt") }
+            .each { libraryjars it }
+    }
+
+    // We want to avoid as much obfuscation as possible. We're only doing this to shrink code size.
+    dontobfuscate; dontoptimize; keepattributes; keepparameternames
+
+    // Proguard will remove directories by default, but that breaks JarMount.
+    keepdirectories 'assets/computercraft/lua**'
+
+    // Preserve ComputerCraft classes - we only want to strip shadowed files.
+    keep 'class dan200.computercraft.** { *; }'
+
+    // Preserve the constructors in Cobalt library class, as we init them via reflection
+    keepclassmembers 'class org.squiddev.cobalt.lib.** { <init>(...); }'
+}
+
+task proguardMove(dependsOn: proguard) {
+    description "Replace the original jar with the minified version"
+    group "compact"
+
+    doLast {
+        Files.move(
+            file("${jar.archivePath.absolutePath.replace(".jar", "")}-min.jar").toPath(),
+            file(jar.archivePath).toPath(),
+            StandardCopyOption.REPLACE_EXISTING
+        )
+    }
+}
+
+reobfJar.dependsOn proguardMove
 
 processResources {
-    inputs.property "version", project.version
-    inputs.property "mcversion", project.minecraft.version
+    inputs.property "version", mod_version
+    inputs.property "mcversion", mc_version
 
-    def grgit = Grgit.open(dir: '.')
-    inputs.property "commithash", grgit.head().id
-
-    def blacklist = ['GitHub', 'dan200', 'Daniel Ratcliffe']
+    def hash = 'none'
     Set<String> contributors = []
+    try {
+        def grgit = Grgit.open(dir: '.')
+        hash = grgit.head().id
 
-    grgit.log().each {
-        if (!blacklist.contains(it.author.name)) contributors.add(it.author.name)
-        if (!blacklist.contains(it.committer.name)) contributors.add(it.committer.name)
-    }
+        def blacklist = ['GitHub', 'dan200', 'Daniel Ratcliffe']
+        grgit.log().each {
+            if (!blacklist.contains(it.author.name)) contributors.add(it.author.name)
+            if (!blacklist.contains(it.committer.name)) contributors.add(it.committer.name)
+        }
+    } catch(Exception ignored) { }
+
+    inputs.property "commithash", hash
 
     from(sourceSets.main.resources.srcDirs) {
         include 'mcmod.info'
         include 'assets/computercraft/lua/rom/help/credits.txt'
 
-        expand 'version':project.version,
-               'mcversion':project.minecraft.version,
-               'gitcontributors':contributors.sort(false, String.CASE_INSENSITIVE_ORDER).join('\n')
+        expand 'version': mod_version,
+               'mcversion': mc_version,
+               'gitcontributors': contributors.sort(false, String.CASE_INSENSITIVE_ORDER).join('\n')
     }
 
     from(sourceSets.main.resources.srcDirs) {
@@ -125,13 +200,148 @@ processResources {
     }
 }
 
+task compressJson(dependsOn: extractAnnotationsJar) {
+    group "compact"
+    description "Minifies all JSON files, stripping whitespace"
+
+    def jarPath = file(jar.archivePath)
+
+    def tempPath = File.createTempFile("input", ".jar", temporaryDir)
+    tempPath.deleteOnExit()
+
+    def gson = new GsonBuilder().create()
+
+    doLast {
+        // Copy over all files in the current jar to the new one, running json files from GSON. As pretty printing
+        // is turned off, they should be minified.
+        new ZipFile(jarPath).withCloseable { inJar ->
+            tempPath.getParentFile().mkdirs()
+            new ZipOutputStream(new BufferedOutputStream(new FileOutputStream(tempPath))).withCloseable { outJar ->
+                inJar.entries().each { entry ->
+                    if(entry.directory) {
+                        outJar.putNextEntry(entry)
+                    } else if(!entry.name.endsWith(".json")) {
+                        outJar.putNextEntry(entry)
+                        inJar.getInputStream(entry).withCloseable { outJar << it }
+                    } else {
+                        ZipEntry newEntry = new ZipEntry(entry.name)
+                        newEntry.setTime(entry.time)
+                        outJar.putNextEntry(newEntry)
+
+                        def element = inJar.getInputStream(entry).withCloseable { gson.fromJson(it.newReader("UTF8"), JsonElement.class) }
+                        outJar.write(gson.toJson(element).getBytes(StandardCharsets.UTF_8))
+                    }
+                }
+
+            }
+        }
+
+        // And replace the original jar again
+        Files.move(tempPath.toPath(), jarPath.toPath(), StandardCopyOption.REPLACE_EXISTING)
+    }
+}
+
+assemble.dependsOn compressJson
+
+// Check tasks
+
+test {
+    useJUnitPlatform()
+    testLogging {
+        events "skipped", "failed"
+    }
+}
+
+license {
+    mapping("java", "SLASHSTAR_STYLE")
+    strictCheck true
+
+    ext.year = Calendar.getInstance().get(Calendar.YEAR)
+}
+
+[licenseMain, licenseFormatMain].forEach {
+    it.configure {
+        include("**/*.java")
+        exclude("dan200/computercraft/api/**")
+        header rootProject.file('config/license/main.txt')
+    }
+}
+
+[licenseTest, licenseFormatTest].forEach {
+    it.configure {
+        include("**/*.java")
+        header rootProject.file('config/license/main.txt')
+    }
+}
+
+gradle.projectsEvaluated {
+    tasks.withType(LicenseFormat) {
+        outputs.upToDateWhen { false }
+    }
+}
+
+
+task licenseAPI(type: LicenseCheck);
+task licenseFormatAPI(type: LicenseFormat);
+[licenseAPI, licenseFormatAPI].forEach {
+    it.configure {
+        source = sourceSets.main.java
+        include("dan200/computercraft/api/**")
+        header rootProject.file('config/license/api.txt')
+    }
+}
+
+// Upload tasks
+
+task checkRelease {
+    group "upload"
+    description "Verifies that everything is ready for a release"
+
+    inputs.property "version", mod_version
+    inputs.file("src/main/resources/assets/computercraft/lua/rom/help/changelog.txt")
+    inputs.file("src/main/resources/assets/computercraft/lua/rom/help/whatsnew.txt")
+
+    doLast {
+        def ok = true
+
+        // Check we're targetting the current version
+        def whatsnew = new File("src/main/resources/assets/computercraft/lua/rom/help/whatsnew.txt").readLines()
+        if (whatsnew[0] != "New features in CC: Tweaked $mod_version") {
+            ok = false
+            project.logger.error("Expected `whatsnew.txt' to target $mod_version.")
+        }
+
+        // Check "read more" exists and trim it
+        def idx = whatsnew.findIndexOf { it == 'Type "help changelog" to see the full version history.' }
+        if (idx == -1) {
+            ok = false
+            project.logger.error("Must mention the changelog in whatsnew.txt")
+        } else {
+            whatsnew = whatsnew.getAt(0 ..< idx)
+        }
+
+        // Check whatsnew and changelog match.
+        def versionChangelog = "# " + whatsnew.join("\n")
+        def changelog = new File("src/main/resources/assets/computercraft/lua/rom/help/changelog.txt").getText()
+        if (!changelog.startsWith(versionChangelog)) {
+            ok = false
+            project.logger.error("whatsnew and changelog are not in sync")
+        }
+
+        if (!ok) throw new IllegalStateException("Could not check release")
+    }
+}
 
 curseforge {
     apiKey = project.hasProperty('curseForgeApiKey') ? project.curseForgeApiKey : ''
     project {
         id = '282001'
-        releaseType = 'beta'
-        changelog = "Release notes can be found on the GitHub repository (https://github.com/SquidDev-CC/CC-Tweaked/releases/tag/v${project.version})."
+        releaseType = 'release'
+        changelog = "Release notes can be found on the GitHub repository (https://github.com/SquidDev-CC/CC-Tweaked/releases/tag/v${mc_version}-${mod_version})."
+
+        relations {
+            incompatible "computercraft"
+        }
     }
 }
 
@@ -159,22 +369,22 @@ uploadArchives {
                 pom.project {
                     name 'CC: Tweaked'
                     packaging 'jar'
-                    description 'A fork of ComputerCraft which aims to provide earlier access to the more experimental and in-development features of the mod.'
+                    description 'CC: Tweaked is a fork of ComputerCraft, adding programmable computers, turtles and more to Minecraft.'
                     url 'https://github.com/SquidDev-CC/CC-Tweaked'
 
                     scm {
-                        url 'https://github.com/dan200/ComputerCraft.git'
+                        url 'https://github.com/SquidDev-CC/CC-Tweaked.git'
                     }
 
                     issueManagement {
                         system 'github'
-                        url 'https://github.com/dan200/ComputerCraft/issues'
+                        url 'https://github.com/SquidDev-CC/CC-Tweaked/issues'
                     }
 
                     licenses {
                         license {
                             name 'ComputerCraft Public License, Version 1.0'
-                            url 'https://github.com/dan200/ComputerCraft/blob/master/LICENSE'
+                            url 'https://github.com/SquidDev-CC/CC-Tweaked/blob/master/LICENSE'
                             distribution 'repo'
                         }
                     }
@@ -188,10 +398,29 @@ uploadArchives {
     }
 }
 
-gradle.projectsEvaluated {
-    tasks.withType(JavaCompile) {
-        options.compilerArgs << "-Xlint"
+githubRelease {
+    token project.hasProperty('githubApiKey') ? project.githubApiKey : ''
+    owner 'SquidDev-CC'
+    repo 'CC-Tweaked'
+    targetCommitish { Grgit.open(dir: '.').branch.current().name }
+
+    tagName "v${mc_version}-${mod_version}"
+    releaseName "[${mc_version}] ${mod_version}"
+    body {
+        "## " + new File("src/main/resources/assets/computercraft/lua/rom/help/whatsnew.txt")
+            .readLines()
+            .takeWhile { it != 'Type "help changelog" to see the full version history.' }
+            .join("\n").trim()
     }
+    prerelease false
+}
+
+def uploadTasks = ["uploadArchives", "curseforge", "githubRelease"]
+uploadTasks.forEach { tasks.getByName(it).dependsOn checkRelease }
+
+task uploadAll(dependsOn: uploadTasks) {
+    group "upload"
+    description "Uploads to all repositories (Maven, Curse, GitHub release)"
 }
 
 runClient.outputs.upToDateWhen { false }

config/checkstyle/checkstyle.xml

@@ -0,0 +1,159 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE module PUBLIC
+    "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
+    "https://checkstyle.org/dtds/configuration_1_3.dtd">
+<module name="Checker">
+    <property name="tabWidth" value="4"/>
+    <property name="charset" value="UTF-8" />
+
+    <module name="SuppressionFilter">
+        <property name="file" value="config/checkstyle/suppressions.xml" />
+    </module>
+
+    <module name="TreeWalker">
+        <!-- Annotations -->
+        <module name="AnnotationLocation" />
+        <module name="AnnotationUseStyle" />
+        <module name="MissingDeprecated">
+            <property name="skipNoJavadoc" value="true" />
+        </module>
+        <module name="MissingOverride" />
+
+        <!-- Blocks -->
+        <module name="EmptyBlock" />
+        <module name="EmptyCatchBlock">
+            <property name="exceptionVariableName" value="ignored" />
+        </module>
+        <module name="LeftCurly">
+            <property name="option" value="nl" />
+            <!-- The defaults, minus lambdas. -->
+            <property name="tokens" value="ANNOTATION_DEF,CLASS_DEF,CTOR_DEF,ENUM_CONSTANT_DEF,ENUM_DEF,INTERFACE_DEF,LITERAL_CASE,LITERAL_CATCH,LITERAL_DEFAULT,LITERAL_DO,LITERAL_ELSE,LITERAL_FINALLY,LITERAL_FOR,LITERAL_IF,LITERAL_SWITCH,LITERAL_SYNCHRONIZED,LITERAL_TRY,LITERAL_WHILE,METHOD_DEF,OBJBLOCK,STATIC_INIT" />
+        </module>
+        <module name="NeedBraces">
+            <property name="allowSingleLineStatement" value="true"/>
+        </module>
+        <module name="RightCurly">
+            <property name="option" value="alone" />
+        </module>
+
+        <!-- Class design. As if we've ever followed good practice here. -->
+        <module name="FinalClass" />
+        <module name="InterfaceIsType" />
+        <module name="MutableException" />
+        <module name="OneTopLevelClass" />
+
+        <!-- Coding -->
+        <module name="ArrayTrailingComma" />
+        <module name="EqualsHashCode" />
+        <!-- FallThrough does not handle unreachable code well -->
+        <module name="IllegalInstantiation" />
+        <module name="IllegalThrows" />
+        <module name="ModifiedControlVariable" />
+        <module name="NoClone" />
+        <module name="NoFinalizer" />
+        <module name="OneStatementPerLine" />
+        <module name="PackageDeclaration" />
+        <module name="SimplifyBooleanExpression" />
+        <module name="SimplifyBooleanReturn" />
+        <module name="StringLiteralEquality" />
+        <module name="UnnecessaryParentheses" />
+
+        <!-- Imports -->
+        <module name="CustomImportOrder" />
+        <module name="IllegalImport" />
+        <module name="RedundantImport" />
+        <module name="UnusedImports" />
+
+        <!-- Javadoc -->
+        <module name="AtclauseOrder" />
+        <!-- TODO: Cleanup our documentation before enabling JavadocMethod, JavadocStyle, JavadocType and SummaryJavadoc. -->
+        <module name="NonEmptyAtclauseDescription" />
+        <module name="SingleLineJavadoc" />
+
+        <!-- Misc -->
+        <module name="ArrayTypeStyle" />
+        <module name="CommentsIndentation" />
+        <module name="Indentation" />
+        <module name="OuterTypeFilename" />
+
+        <!-- Modifiers -->
+        <module name="ModifierOrder" />
+        <module name="RedundantModifier" />
+
+        <!-- Naming -->
+        <module name="ClassTypeParameterName" />
+        <module name="InterfaceTypeParameterName" />
+        <module name="LambdaParameterName" />
+        <module name="LocalFinalVariableName" />
+        <module name="LocalVariableName" />
+        <!-- Allow an optional m_ on private members -->
+        <module name="MemberName">
+            <property name="applyToPrivate" value="false" />
+            <property name="applyToPackage" value="false" />
+        </module>
+        <module name="MemberName">
+            <property name="format" value="^(m_)?[a-z][a-zA-Z0-9]*$" />
+            <property name="applyToPrivate" value="true" />
+            <property name="applyToPackage" value="true" />
+        </module>
+        <module name="MethodName" />
+        <module name="MethodTypeParameterName" />
+        <module name="PackageName">
+            <property name="format" value="^dan200\.computercraf(\.[a-z][a-z0-9]*)*" />
+        </module>
+        <module name="ParameterName" />
+        <module name="StaticVariableName">
+            <property name="format" value="^[a-z][a-zA-Z0-9]*|CAPABILITY(_[A-Z]+)?$" />
+            <property name="applyToPrivate" value="false" />
+        </module>
+        <module name="StaticVariableName">
+            <property name="format" value="^(s_)?[a-z][a-zA-Z0-9]*|CAPABILITY(_[A-Z]+)?$" />
+            <property name="applyToPrivate" value="true" />
+        </module>
+        <module name="TypeName" />
+
+        <!-- Whitespace -->
+        <module name="EmptyForInitializerPad"/>
+        <module name="EmptyForIteratorPad">
+            <property name="option" value="space"/>
+        </module>
+        <module name="GenericWhitespace" />
+        <module name="MethodParamPad" />
+        <module name="NoLineWrap" />
+        <module name="NoWhitespaceAfter">
+            <property name="tokens" value="AT,INC,DEC,UNARY_MINUS,UNARY_PLUS,BNOT,LNOT,DOT,ARRAY_DECLARATOR,INDEX_OP" />
+        </module>
+        <module name="NoWhitespaceBefore" />
+        <!-- TODO: Decide on an OperatorWrap style. -->
+        <module name="ParenPad">
+            <property name="option" value="space" />
+            <property name="tokens" value="ANNOTATION,ANNOTATION_FIELD_DEF,CTOR_CALL,CTOR_DEF,ENUM_CONSTANT_DEF,LITERAL_CATCH,LITERAL_DO,LITERAL_FOR,LITERAL_IF,LITERAL_NEW,LITERAL_SWITCH,LITERAL_SYNCHRONIZED,LITERAL_WHILE,METHOD_CALL,METHOD_DEF,RESOURCE_SPECIFICATION,SUPER_CTOR_CALL,LAMBDA" />
+        </module>
+        <module name="ParenPad">
+            <property name="option" value="nospace" />
+            <property name="tokens" value="DOT,EXPR,QUESTION" />
+        </module>
+        <module name="SeparatorWrap">
+            <property name="option" value="eol" />
+            <property name="tokens" value="COMMA,SEMI,ELLIPSIS,ARRAY_DECLARATOR,RBRACK,METHOD_REF" />
+        </module>
+        <module name="SeparatorWrap">
+            <property name="option" value="nl" />
+            <property name="tokens" value="DOT,AT" />
+        </module>
+        <module name="SingleSpaceSeparator" />
+        <module name="TypecastParenPad" />
+        <module name="WhitespaceAfter">
+            <property name="tokens" value="COMMA" />
+        </module>
+        <module name="WhitespaceAround">
+            <property name="allowEmptyConstructors" value="true" />
+            <property name="ignoreEnhancedForColon" value="false" />
+            <property name="tokens" value="ASSIGN,BAND,BAND_ASSIGN,BOR,BOR_ASSIGN,BSR,BSR_ASSIGN,BXOR,BXOR_ASSIGN,COLON,DIV,DIV_ASSIGN,DO_WHILE,EQUAL,GE,GT,LAMBDA,LAND,LCURLY,LE,LITERAL_RETURN,LOR,LT,MINUS,MINUS_ASSIGN,MOD,MOD_ASSIGN,NOT_EQUAL,PLUS,PLUS_ASSIGN,QUESTION,RCURLY,SL,SLIST,SL_ASSIGN,SR,SR_ASSIGN,STAR,STAR_ASSIGN,LITERAL_ASSERT,TYPE_EXTENSION_AND" />
+        </module>
+    </module>
+
+    <module name="FileTabCharacter" />
+    <module name="NewlineAtEndOfFile" />
+</module>
+

config/checkstyle/suppressions.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE suppressions PUBLIC
+    "-//Checkstyle//DTD SuppressionFilter Configuration 1.2//EN"
+    "https://checkstyle.org/dtds/suppressions_1_2.dtd">
+<suppressions>
+    <!-- All the config options and method fields. -->
+    <suppress checks="StaticVariableName" files=".*[\\/]ComputerCraft.java" />
+    <suppress checks="StaticVariableName" files=".*[\\/]ComputerCraftAPI.java" />
+</suppressions>

config/license/api.txt

@@ -0,0 +1,3 @@
+This file is part of the public ComputerCraft API - http://www.computercraft.info
+Copyright Daniel Ratcliffe, 2011-${year}. This API may be redistributed unmodified and in full only.
+For help using the API, and posting your mods, visit the forums at computercraft.info.

config/license/main.txt

@@ -0,0 +1,3 @@
+This file is part of ComputerCraft - http://www.computercraft.info
+Copyright Daniel Ratcliffe, 2011-${year}. Do not distribute without permission.
+Send enquiries to dratcliffe@gmail.com

gradle.properties

@@ -0,0 +1,7 @@
+# Mod properties
+mod_version=1.85.0
+
+# Minecraft properties
+mc_version=1.12.2
+forge_version=14.23.4.2749
+mappings_version=snapshot_20180724

gradle/wrapper/gradle-wrapper.properties

@@ -2,4 +2,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.3-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.6-bin.zip

settings.gradle

@@ -1 +1 @@
-rootProject.name = 'cc-tweaked'
+rootProject.name = "cc-tweaked-${mc_version}"

src/main/java/dan200/computercraft/CCTweaked.java

@@ -0,0 +1,30 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2019. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft;
+
+import net.minecraftforge.fml.common.Mod;
+import net.minecraftforge.fml.common.network.NetworkCheckHandler;
+import net.minecraftforge.fml.relauncher.Side;
+
+import java.util.Map;
+
+/**
+ * A stub mod for CC: Tweaked. This doesn't have any functionality (everything of note is done in
+ * {@link ComputerCraft}), but people may depend on this if they require CC: Tweaked functionality.
+ */
+@Mod(
+    modid = "cctweaked", name = ComputerCraft.NAME, version = ComputerCraft.VERSION,
+    acceptableRemoteVersions = "*"
+)
+public class CCTweaked
+{
+    @NetworkCheckHandler
+    public boolean onNetworkConnect( Map<String, String> mods, Side side )
+    {
+        return true;
+    }
+}

src/main/java/dan200/computercraft/ComputerCraft.java

@@ -24,37 +24,38 @@ import dan200.computercraft.api.turtle.event.TurtleAction;
 import dan200.computercraft.core.apis.AddressPredicate;
 import dan200.computercraft.core.apis.ApiFactories;
 import dan200.computercraft.core.apis.http.websocket.Websocket;
+import dan200.computercraft.core.computer.MainThread;
 import dan200.computercraft.core.filesystem.ComboMount;
 import dan200.computercraft.core.filesystem.FileMount;
-import dan200.computercraft.core.filesystem.FileSystemMount;
-import dan200.computercraft.core.terminal.Terminal;
+import dan200.computercraft.core.filesystem.JarMount;
 import dan200.computercraft.core.tracking.Tracking;
 import dan200.computercraft.shared.*;
 import dan200.computercraft.shared.computer.blocks.BlockCommandComputer;
 import dan200.computercraft.shared.computer.blocks.BlockComputer;
-import dan200.computercraft.shared.computer.blocks.TileComputer;
 import dan200.computercraft.shared.computer.core.ClientComputerRegistry;
-import dan200.computercraft.shared.computer.core.ComputerFamily;
-import dan200.computercraft.shared.computer.core.ServerComputer;
 import dan200.computercraft.shared.computer.core.ServerComputerRegistry;
+import dan200.computercraft.shared.computer.items.ItemCommandComputer;
+import dan200.computercraft.shared.computer.items.ItemComputer;
 import dan200.computercraft.shared.media.items.ItemDiskExpanded;
 import dan200.computercraft.shared.media.items.ItemDiskLegacy;
 import dan200.computercraft.shared.media.items.ItemPrintout;
 import dan200.computercraft.shared.media.items.ItemTreasureDisk;
 import dan200.computercraft.shared.peripheral.common.BlockPeripheral;
-import dan200.computercraft.shared.peripheral.diskdrive.TileDiskDrive;
+import dan200.computercraft.shared.peripheral.common.ItemPeripheral;
 import dan200.computercraft.shared.peripheral.modem.wired.BlockCable;
 import dan200.computercraft.shared.peripheral.modem.wired.BlockWiredModemFull;
+import dan200.computercraft.shared.peripheral.modem.wired.ItemCable;
 import dan200.computercraft.shared.peripheral.modem.wireless.BlockAdvancedModem;
+import dan200.computercraft.shared.peripheral.modem.wireless.ItemAdvancedModem;
 import dan200.computercraft.shared.peripheral.modem.wireless.WirelessNetwork;
-import dan200.computercraft.shared.peripheral.printer.TilePrinter;
 import dan200.computercraft.shared.pocket.items.ItemPocketComputer;
 import dan200.computercraft.shared.pocket.peripherals.PocketModem;
 import dan200.computercraft.shared.pocket.peripherals.PocketSpeaker;
-import dan200.computercraft.shared.proxy.ICCTurtleProxy;
-import dan200.computercraft.shared.proxy.IComputerCraftProxy;
+import dan200.computercraft.shared.proxy.ComputerCraftProxyCommon;
 import dan200.computercraft.shared.turtle.blocks.BlockTurtle;
-import dan200.computercraft.shared.turtle.blocks.TileTurtle;
+import dan200.computercraft.shared.turtle.items.ItemTurtleAdvanced;
+import dan200.computercraft.shared.turtle.items.ItemTurtleLegacy;
+import dan200.computercraft.shared.turtle.items.ItemTurtleNormal;
 import dan200.computercraft.shared.turtle.upgrades.*;
 import dan200.computercraft.shared.util.CreativeTabMain;
 import dan200.computercraft.shared.util.IDAssigner;
@@ -62,22 +63,17 @@ import dan200.computercraft.shared.util.IoUtil;
 import dan200.computercraft.shared.wired.CapabilityWiredElement;
 import dan200.computercraft.shared.wired.WiredNode;
 import net.minecraft.entity.player.EntityPlayer;
-import net.minecraft.entity.player.EntityPlayerMP;
+import net.minecraft.item.ItemBlock;
 import net.minecraft.item.ItemStack;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.EnumFacing;
-import net.minecraft.util.EnumHand;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.IBlockAccess;
 import net.minecraft.world.World;
-import net.minecraftforge.fml.common.FMLCommonHandler;
-import net.minecraftforge.fml.common.Mod;
-import net.minecraftforge.fml.common.SidedProxy;
+import net.minecraftforge.common.DimensionManager;
+import net.minecraftforge.fml.common.*;
 import net.minecraftforge.fml.common.event.*;
-import net.minecraftforge.fml.common.network.NetworkRegistry;
-import net.minecraftforge.fml.common.network.simpleimpl.IMessage;
-import net.minecraftforge.fml.common.network.simpleimpl.SimpleNetworkWrapper;
 import net.minecraftforge.fml.relauncher.Side;
 import org.apache.logging.log4j.Logger;
 
@@ -85,34 +81,21 @@ import java.io.*;
 import java.net.MalformedURLException;
 import java.net.URISyntaxException;
 import java.net.URL;
-import java.nio.file.FileSystem;
-import java.nio.file.FileSystems;
-import java.nio.file.Files;
-import java.util.ArrayList;
-import java.util.EnumSet;
-import java.util.List;
-import java.util.ServiceConfigurationError;
+import java.util.*;
+import java.util.concurrent.TimeUnit;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 
 @Mod(
-    modid = ComputerCraft.MOD_ID, name = "CC: Tweaked", version = "${version}",
+    modid = ComputerCraft.MOD_ID, name = ComputerCraft.NAME, version = ComputerCraft.VERSION,
     guiFactory = "dan200.computercraft.client.gui.GuiConfigCC$Factory",
     dependencies = "required:forge@[14.23.4.2746,)"
 )
 public class ComputerCraft
 {
     public static final String MOD_ID = "computercraft";
-
-    // GUI IDs
-    public static final int diskDriveGUIID = 100;
-    public static final int computerGUIID = 101;
-    public static final int printerGUIID = 102;
-    public static final int turtleGUIID = 103;
-    // ComputerCraftEdu uses ID 104
-    public static final int printoutGUIID = 105;
-    public static final int pocketComputerGUIID = 106;
-    public static final int viewComputerGUIID = 110;
+    static final String VERSION = "${version}";
+    static final String NAME = "CC: Tweaked";
 
     // Configuration options
     public static final String[] DEFAULT_HTTP_WHITELIST = new String[] { "*" };
@@ -130,9 +113,12 @@ public class ComputerCraft
     public static boolean disable_lua51_features = false;
     public static String default_computer_settings = "";
     public static boolean debug_enable = true;
-    public static int computer_threads = 1;
     public static boolean logPeripheralErrors = false;
 
+    public static int computer_threads = 1;
+    public static long maxMainGlobalTime = TimeUnit.MILLISECONDS.toNanos( 10 );
+    public static long maxMainComputerTime = TimeUnit.MILLISECONDS.toNanos( 5 );
+
     public static boolean http_enable = true;
     public static boolean http_websocket_enable = true;
     public static AddressPredicate http_whitelist = new AddressPredicate( DEFAULT_HTTP_WHITELIST );
@@ -169,54 +155,77 @@ public class ComputerCraft
     public static final int terminalHeight_pocketComputer = 20;
 
     // Blocks and Items
-    public static class Blocks
+    public static final class Blocks
     {
         public static BlockComputer computer;
-        public static BlockPeripheral peripheral;
-        public static BlockCable cable;
+        public static BlockCommandComputer commandComputer;
+
         public static BlockTurtle turtle;
         public static BlockTurtle turtleExpanded;
         public static BlockTurtle turtleAdvanced;
-        public static BlockCommandComputer commandComputer;
+
+        public static BlockPeripheral peripheral;
+        public static BlockCable cable;
         public static BlockAdvancedModem advancedModem;
         public static BlockWiredModemFull wiredModemFull;
     }
 
-    public static class Items
+    public static final class Items
     {
+        public static ItemComputer computer;
+        public static ItemCommandComputer commandComputer;
+
+        public static ItemTurtleLegacy turtle;
+        public static ItemTurtleNormal turtleExpanded;
+        public static ItemTurtleAdvanced turtleAdvanced;
+
+        public static ItemPocketComputer pocketComputer;
+
         public static ItemDiskLegacy disk;
         public static ItemDiskExpanded diskExpanded;
-        public static ItemPrintout printout;
         public static ItemTreasureDisk treasureDisk;
-        public static ItemPocketComputer pocketComputer;
+
+        public static ItemPrintout printout;
+
+        public static ItemPeripheral peripheral;
+        public static ItemAdvancedModem advancedModem;
+        public static ItemCable cable;
+        public static ItemBlock wiredModemFull;
     }
 
-    public static class Upgrades
+    public static final class TurtleUpgrades
     {
         public static TurtleModem wirelessModem;
+        public static TurtleModem advancedModem;
+        public static TurtleSpeaker speaker;
+
         public static TurtleCraftingTable craftingTable;
         public static TurtleSword diamondSword;
         public static TurtleShovel diamondShovel;
         public static TurtleTool diamondPickaxe;
         public static TurtleAxe diamondAxe;
         public static TurtleHoe diamondHoe;
-        public static TurtleModem advancedModem;
-        public static TurtleSpeaker turtleSpeaker;
     }
 
-    public static class PocketUpgrades
+    public static final class PocketUpgrades
     {
         public static PocketModem wirelessModem;
         public static PocketModem advancedModem;
+        public static PocketSpeaker speaker;
+
+        @Deprecated
         public static PocketSpeaker pocketSpeaker;
     }
 
-    // Registries
-    public static ClientComputerRegistry clientComputerRegistry = new ClientComputerRegistry();
-    public static ServerComputerRegistry serverComputerRegistry = new ServerComputerRegistry();
+    @Deprecated
+    public static final class Upgrades
+    {
+        public static TurtleModem advancedModem;
+    }
 
-    // Networking
-    public static SimpleNetworkWrapper networkWrapper;
+    // Registries
+    public static final ClientComputerRegistry clientComputerRegistry = new ClientComputerRegistry();
+    public static final ServerComputerRegistry serverComputerRegistry = new ServerComputerRegistry();
 
     // Creative
     public static CreativeTabMain mainCreativeTab;
@@ -228,14 +237,14 @@ public class ComputerCraft
     public static List<IPeripheralProvider> peripheralProviders = new ArrayList<>();
 
     // Implementation
-    @Mod.Instance( value = ComputerCraft.MOD_ID )
+    @Mod.Instance( ComputerCraft.MOD_ID )
     public static ComputerCraft instance;
 
-    @SidedProxy( clientSide = "dan200.computercraft.client.proxy.ComputerCraftProxyClient", serverSide = "dan200.computercraft.server.proxy.ComputerCraftProxyServer" )
-    public static IComputerCraftProxy proxy;
-
-    @SidedProxy( clientSide = "dan200.computercraft.client.proxy.CCTurtleProxyClient", serverSide = "dan200.computercraft.server.proxy.CCTurtleProxyServer" )
-    public static ICCTurtleProxy turtleProxy;
+    @SidedProxy(
+        clientSide = "dan200.computercraft.client.proxy.ComputerCraftProxyClient",
+        serverSide = "dan200.computercraft.shared.proxy.ComputerCraftProxyCommon"
+    )
+    private static ComputerCraftProxyCommon proxy;
 
     @Mod.EventHandler
     public void preInit( FMLPreInitializationEvent event )
@@ -245,24 +254,19 @@ public class ComputerCraft
         // Load config
         Config.load( event.getSuggestedConfigurationFile() );
 
-        // Setup network
-        networkWrapper = NetworkRegistry.INSTANCE.newSimpleChannel( ComputerCraft.MOD_ID );
-
         proxy.preInit();
-        turtleProxy.preInit();
     }
 
     @Mod.EventHandler
     public void init( FMLInitializationEvent event )
     {
         proxy.init();
-        turtleProxy.init();
     }
 
     @Mod.EventHandler
     public void onServerStarting( FMLServerStartingEvent event )
     {
-        proxy.initServer( event.getServer() );
+        ComputerCraftProxyCommon.initServer( event.getServer() );
     }
 
     @Mod.EventHandler
@@ -272,6 +276,7 @@ public class ComputerCraft
         {
             ComputerCraft.serverComputerRegistry.reset();
             WirelessNetwork.resetNetworks();
+            MainThread.reset();
             Tracking.reset();
         }
     }
@@ -283,65 +288,14 @@ public class ComputerCraft
         {
             ComputerCraft.serverComputerRegistry.reset();
             WirelessNetwork.resetNetworks();
+            MainThread.reset();
             Tracking.reset();
         }
     }
 
     public static String getVersion()
     {
-        return "${version}";
-    }
-
-    public static void openDiskDriveGUI( EntityPlayer player, TileDiskDrive drive )
-    {
-        BlockPos pos = drive.getPos();
-        player.openGui( ComputerCraft.instance, ComputerCraft.diskDriveGUIID, player.getEntityWorld(), pos.getX(), pos.getY(), pos.getZ() );
-    }
-
-    public static void openComputerGUI( EntityPlayer player, TileComputer computer )
-    {
-        BlockPos pos = computer.getPos();
-        player.openGui( ComputerCraft.instance, ComputerCraft.computerGUIID, player.getEntityWorld(), pos.getX(), pos.getY(), pos.getZ() );
-    }
-
-    public static void openPrinterGUI( EntityPlayer player, TilePrinter printer )
-    {
-        BlockPos pos = printer.getPos();
-        player.openGui( ComputerCraft.instance, ComputerCraft.printerGUIID, player.getEntityWorld(), pos.getX(), pos.getY(), pos.getZ() );
-    }
-
-    public static void openTurtleGUI( EntityPlayer player, TileTurtle turtle )
-    {
-        BlockPos pos = turtle.getPos();
-        player.openGui( instance, ComputerCraft.turtleGUIID, player.getEntityWorld(), pos.getX(), pos.getY(), pos.getZ() );
-    }
-
-    public static void openPrintoutGUI( EntityPlayer player, EnumHand hand )
-    {
-        player.openGui( ComputerCraft.instance, ComputerCraft.printoutGUIID, player.getEntityWorld(), hand.ordinal(), 0, 0 );
-    }
-
-    public static void openPocketComputerGUI( EntityPlayer player, EnumHand hand )
-    {
-        player.openGui( ComputerCraft.instance, ComputerCraft.pocketComputerGUIID, player.getEntityWorld(), hand.ordinal(), 0, 0 );
-    }
-
-    public static void openComputerGUI( EntityPlayer player, ServerComputer computer )
-    {
-        ComputerFamily family = computer.getFamily();
-        int width = 0, height = 0;
-        Terminal terminal = computer.getTerminal();
-        if( terminal != null )
-        {
-            width = terminal.getWidth();
-            height = terminal.getHeight();
-        }
-
-        // Pack useful terminal information into the various coordinate bits.
-        // These are extracted in ComputerCraftProxyCommon.getClientGuiElement
-        player.openGui( ComputerCraft.instance, ComputerCraft.viewComputerGUIID, player.getEntityWorld(),
-            computer.getInstanceID(), family.ordinal(), (width & 0xFFFF) << 16 | (height & 0xFFFF)
-        );
+        return VERSION;
     }
 
     private static File getBaseDir()
@@ -354,41 +308,6 @@ public class ComputerCraft
         return new File( getBaseDir(), "resourcepacks" );
     }
 
-    public static File getWorldDir( World world )
-    {
-        return proxy.getWorldDir( world );
-    }
-
-    public static void sendToPlayer( EntityPlayer player, IMessage packet )
-    {
-        networkWrapper.sendTo( packet, (EntityPlayerMP) player );
-    }
-
-    public static void sendToAllPlayers( IMessage packet )
-    {
-        networkWrapper.sendToAll( packet );
-    }
-
-    public static void sendToServer( IMessage packet )
-    {
-        networkWrapper.sendToServer( packet );
-    }
-
-    public static void sendToAllAround( IMessage packet, NetworkRegistry.TargetPoint point )
-    {
-        networkWrapper.sendToAllAround( packet, point );
-    }
-
-    public static boolean canPlayerUseCommands( EntityPlayer player )
-    {
-        MinecraftServer server = player.getServer();
-        if( server != null )
-        {
-            return server.getPlayerList().canSendCommands( player.getGameProfile() );
-        }
-        return false;
-    }
-
     @Deprecated
     public static void registerPermissionProvider( ITurtlePermissionProvider provider )
     {
@@ -455,7 +374,7 @@ public class ComputerCraft
     @Deprecated
     public static int createUniqueNumberedSaveDir( World world, String parentSubPath )
     {
-        return IDAssigner.getNextIDFromDirectory( new File( getWorldDir( world ), parentSubPath ) );
+        return IDAssigner.getNextIDFromDirectory( parentSubPath );
     }
 
     @Deprecated
@@ -463,7 +382,7 @@ public class ComputerCraft
     {
         try
         {
-            return new FileMount( new File( getWorldDir( world ), subPath ), capacity );
+            return new FileMount( new File( getWorldDir(), subPath ), capacity );
         }
         catch( Exception e )
         {
@@ -471,6 +390,27 @@ public class ComputerCraft
         }
     }
 
+    private static void loadFromFile( List<IMount> mounts, File file, String path, boolean allowMissing )
+    {
+        try
+        {
+            if( file.isFile() )
+            {
+                mounts.add( new JarMount( file, path ) );
+            }
+            else
+            {
+                File subResource = new File( file, path );
+                if( subResource.exists() ) mounts.add( new FileMount( subResource, 0 ) );
+            }
+        }
+        catch( IOException | RuntimeException e )
+        {
+            if( allowMissing && e instanceof FileNotFoundException ) return;
+            ComputerCraft.log.error( "Could not load mount '" + path + " 'from '" + file.getName() + "'", e );
+        }
+    }
+
     @Deprecated
     public static IMount createResourceMount( Class<?> modClass, String domain, String subPath )
     {
@@ -490,20 +430,26 @@ public class ComputerCraft
             }
         }
 
-        // Mount from mod jar
+        // Mount from mod jars, preferring the specified one.
         File modJar = getContainingJar( modClass );
+        Set<File> otherMods = new HashSet<>();
+        for( ModContainer container : Loader.instance().getActiveModList() )
+        {
+            File modFile = container.getSource();
+            if( modFile != null && !modFile.equals( modJar ) && modFile.exists() )
+            {
+                otherMods.add( container.getSource() );
+            }
+        }
+
+        for( File file : otherMods )
+        {
+            loadFromFile( mounts, file, subPath, true );
+        }
+
         if( modJar != null )
         {
-            try
-            {
-                FileSystem fs = FileSystems.newFileSystem( modJar.toPath(), ComputerCraft.class.getClassLoader() );
-                mounts.add( new FileSystemMount( fs, subPath ) );
-            }
-            catch( IOException | RuntimeException | ServiceConfigurationError e )
-            {
-                ComputerCraft.log.error( "Could not load mount from mod jar", e );
-                // Ignore
-            }
+            loadFromFile( mounts, modJar, subPath, false );
         }
 
         // Mount from resource packs
@@ -513,30 +459,8 @@ public class ComputerCraft
             String[] resourcePacks = resourcePackDir.list();
             for( String resourcePackName : resourcePacks )
             {
-                try
-                {
-                    File resourcePack = new File( resourcePackDir, resourcePackName );
-                    if( !resourcePack.isDirectory() )
-                    {
-                        // Mount a resource pack from a jar
-                        FileSystem fs = FileSystems.newFileSystem( resourcePack.toPath(), ComputerCraft.class.getClassLoader() );
-                        if( Files.exists( fs.getPath( subPath ) ) ) mounts.add( new FileSystemMount( fs, subPath ) );
-                    }
-                    else
-                    {
-                        // Mount a resource pack from a folder
-                        File subResource = new File( resourcePack, subPath );
-                        if( subResource.exists() )
-                        {
-                            IMount resourcePackMount = new FileMount( subResource, 0 );
-                            mounts.add( resourcePackMount );
-                        }
-                    }
-                }
-                catch( IOException | RuntimeException | ServiceConfigurationError e )
-                {
-                    ComputerCraft.log.error( "Could not load resource pack '" + resourcePackName + "'", e );
-                }
+                File resourcePack = new File( resourcePackDir, resourcePackName );
+                loadFromFile( mounts, resourcePack, subPath, true );
             }
         }
 
@@ -642,7 +566,7 @@ public class ComputerCraft
     private static File getContainingJar( Class<?> modClass )
     {
         String path = modClass.getProtectionDomain().getCodeSource().getLocation().getPath();
-        int bangIndex = path.indexOf( "!" );
+        int bangIndex = path.indexOf( '!' );
         if( bangIndex >= 0 )
         {
             path = path.substring( 0, bangIndex );
@@ -673,17 +597,28 @@ public class ComputerCraft
     private static File getDebugCodeDir( Class<?> modClass )
     {
         String path = modClass.getProtectionDomain().getCodeSource().getLocation().getPath();
-        int bangIndex = path.indexOf( "!" );
+        int bangIndex = path.indexOf( '!' );
         return bangIndex >= 0 ? null : new File( new File( path ).getParentFile(), "../.." );
     }
 
     @Deprecated
     public static void registerTurtleUpgrade( ITurtleUpgrade upgrade )
     {
-        TurtleUpgrades.register( upgrade );
+        dan200.computercraft.shared.TurtleUpgrades.register( upgrade );
+    }
+
+    public static File getWorldDir()
+    {
+        return DimensionManager.getCurrentSaveRootDirectory();
     }
 
     //region Compatibility
+    @Deprecated
+    public static File getWorldDir( World world )
+    {
+        return DimensionManager.getCurrentSaveRootDirectory();
+    }
+
     @Deprecated
     public static IMedia getMedia( ItemStack stack )
     {
@@ -699,7 +634,7 @@ public class ComputerCraft
     @Deprecated
     public static ITurtleUpgrade getTurtleUpgrade( ItemStack stack )
     {
-        return TurtleUpgrades.get( stack );
+        return dan200.computercraft.shared.TurtleUpgrades.get( stack );
     }
 
     @Deprecated
@@ -711,7 +646,7 @@ public class ComputerCraft
     @Deprecated
     public static ITurtleUpgrade getTurtleUpgrade( String id )
     {
-        return TurtleUpgrades.get( id );
+        return dan200.computercraft.shared.TurtleUpgrades.get( id );
     }
 
     @Deprecated
@@ -719,5 +654,12 @@ public class ComputerCraft
     {
         return Peripherals.getPeripheral( world, pos, side );
     }
+
+    @Deprecated
+    public static boolean canPlayerUseCommands( EntityPlayer player )
+    {
+        MinecraftServer server = player.getServer();
+        return server != null && server.getPlayerList().canSendCommands( player.getGameProfile() );
+    }
     //endregion
 }

src/main/java/dan200/computercraft/api/AbstractTurtleUpgrade.java

@@ -1,10 +1,9 @@
 /*
- * This file is part of ComputerCraft - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2019. Do not distribute without permission.
- * Send enquiries to dratcliffe@gmail.com
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2019. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
  */
-
-package dan200.computercraft.shared.turtle.upgrades;
+package dan200.computercraft.api;
 
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.api.turtle.TurtleUpgradeType;
@@ -15,6 +14,11 @@ import net.minecraft.util.ResourceLocation;
 
 import javax.annotation.Nonnull;
 
+/**
+ * A base class for {@link ITurtleUpgrade}s.
+ *
+ * One does not have to use this, but it does provide a convenient template.
+ */
 public abstract class AbstractTurtleUpgrade implements ITurtleUpgrade
 {
     private final ResourceLocation id;
@@ -23,7 +27,7 @@ public abstract class AbstractTurtleUpgrade implements ITurtleUpgrade
     private final String adjective;
     private final ItemStack stack;
 
-    public AbstractTurtleUpgrade( ResourceLocation id, int legacyId, TurtleUpgradeType type, String adjective, ItemStack stack )
+    protected AbstractTurtleUpgrade( ResourceLocation id, int legacyId, TurtleUpgradeType type, String adjective, ItemStack stack )
     {
         this.id = id;
         this.legacyId = legacyId;
@@ -32,16 +36,31 @@ public abstract class AbstractTurtleUpgrade implements ITurtleUpgrade
         this.stack = stack;
     }
 
-    public AbstractTurtleUpgrade( ResourceLocation id, int legacyId, TurtleUpgradeType type, String adjective, Item item )
+    protected AbstractTurtleUpgrade( ResourceLocation id, int legacyId, TurtleUpgradeType type, String adjective, Item item )
     {
         this( id, legacyId, type, adjective, new ItemStack( item ) );
     }
 
-    public AbstractTurtleUpgrade( ResourceLocation id, int legacyId, TurtleUpgradeType type, String adjective, Block block )
+    protected AbstractTurtleUpgrade( ResourceLocation id, int legacyId, TurtleUpgradeType type, String adjective, Block block )
     {
         this( id, legacyId, type, adjective, new ItemStack( block ) );
     }
 
+    protected AbstractTurtleUpgrade( ResourceLocation id, int legacyId, TurtleUpgradeType type, ItemStack stack )
+    {
+        this( id, legacyId, type, "upgrade." + id + ".adjective", stack );
+    }
+
+    protected AbstractTurtleUpgrade( ResourceLocation id, int legacyId, TurtleUpgradeType type, Item item )
+    {
+        this( id, legacyId, type, new ItemStack( item ) );
+    }
+
+    protected AbstractTurtleUpgrade( ResourceLocation id, int legacyId, TurtleUpgradeType type, Block block )
+    {
+        this( id, legacyId, type, new ItemStack( block ) );
+    }
+
     @Nonnull
     @Override
     public final ResourceLocation getUpgradeID()

src/main/java/dan200/computercraft/api/ComputerCraftAPI.java

@@ -173,8 +173,8 @@ public final class ComputerCraftAPI
      * Registers a peripheral provider to convert blocks into {@link IPeripheral} implementations.
      *
      * @param provider The peripheral provider to register.
-     * @see dan200.computercraft.api.peripheral.IPeripheral
-     * @see dan200.computercraft.api.peripheral.IPeripheralProvider
+     * @see IPeripheral
+     * @see IPeripheralProvider
      */
     public static void registerPeripheralProvider( @Nonnull IPeripheralProvider provider )
     {
@@ -198,7 +198,7 @@ public final class ComputerCraftAPI
      * this during the load() method of your mod.
      *
      * @param upgrade The turtle upgrade to register.
-     * @see dan200.computercraft.api.turtle.ITurtleUpgrade
+     * @see ITurtleUpgrade
      */
     public static void registerTurtleUpgrade( @Nonnull ITurtleUpgrade upgrade )
     {
@@ -223,7 +223,7 @@ public final class ComputerCraftAPI
      * Registers a bundled redstone provider to provide bundled redstone output for blocks.
      *
      * @param provider The bundled redstone provider to register.
-     * @see dan200.computercraft.api.redstone.IBundledRedstoneProvider
+     * @see IBundledRedstoneProvider
      */
     public static void registerBundledRedstoneProvider( @Nonnull IBundledRedstoneProvider provider )
     {
@@ -249,7 +249,7 @@ public final class ComputerCraftAPI
      * @param side  The side to extract the bundled redstone output from.
      * @return If there is a block capable of emitting bundled redstone at the location, it's signal (0-65535) will be returned.
      * If there is no block capable of emitting bundled redstone at the location, -1 will be returned.
-     * @see dan200.computercraft.api.redstone.IBundledRedstoneProvider
+     * @see IBundledRedstoneProvider
      */
     public static int getBundledRedstoneOutput( @Nonnull World world, @Nonnull BlockPos pos, @Nonnull EnumFacing side )
     {
@@ -272,7 +272,7 @@ public final class ComputerCraftAPI
      * Registers a media provider to provide {@link IMedia} implementations for Items
      *
      * @param provider The media provider to register.
-     * @see dan200.computercraft.api.media.IMediaProvider
+     * @see IMediaProvider
      */
     public static void registerMediaProvider( @Nonnull IMediaProvider provider )
     {
@@ -294,7 +294,7 @@ public final class ComputerCraftAPI
      * Registers a permission provider to restrict where turtles can move or build.
      *
      * @param provider The turtle permission provider to register.
-     * @see dan200.computercraft.api.permissions.ITurtlePermissionProvider
+     * @see ITurtlePermissionProvider
      * @deprecated Prefer using {@link dan200.computercraft.api.turtle.event.TurtleBlockEvent} or the standard Forge events.
      */
     @Deprecated
@@ -438,50 +438,50 @@ public final class ComputerCraftAPI
                 computerCraft_getVersion = findCCMethod( "getVersion", new Class<?>[] {
                 } );
                 computerCraft_createUniqueNumberedSaveDir = findCCMethod( "createUniqueNumberedSaveDir", new Class<?>[] {
-                    World.class, String.class
+                    World.class, String.class,
                 } );
                 computerCraft_createSaveDirMount = findCCMethod( "createSaveDirMount", new Class<?>[] {
-                    World.class, String.class, Long.TYPE
+                    World.class, String.class, Long.TYPE,
                 } );
                 computerCraft_createResourceMount = findCCMethod( "createResourceMount", new Class<?>[] {
-                    Class.class, String.class, String.class
+                    Class.class, String.class, String.class,
                 } );
                 computerCraft_registerPeripheralProvider = findCCMethod( "registerPeripheralProvider", new Class<?>[] {
-                    IPeripheralProvider.class
+                    IPeripheralProvider.class,
                 } );
                 computerCraft_registerTurtleUpgrade = findCCMethod( "registerTurtleUpgrade", new Class<?>[] {
-                    ITurtleUpgrade.class
+                    ITurtleUpgrade.class,
                 } );
                 computerCraft_registerBundledRedstoneProvider = findCCMethod( "registerBundledRedstoneProvider", new Class<?>[] {
-                    IBundledRedstoneProvider.class
+                    IBundledRedstoneProvider.class,
                 } );
                 computerCraft_getDefaultBundledRedstoneOutput = findCCMethod( "getDefaultBundledRedstoneOutput", new Class<?>[] {
-                    World.class, BlockPos.class, EnumFacing.class
+                    World.class, BlockPos.class, EnumFacing.class,
                 } );
                 computerCraft_registerMediaProvider = findCCMethod( "registerMediaProvider", new Class<?>[] {
-                    IMediaProvider.class
+                    IMediaProvider.class,
                 } );
                 computerCraft_registerPermissionProvider = findCCMethod( "registerPermissionProvider", new Class<?>[] {
-                    ITurtlePermissionProvider.class
+                    ITurtlePermissionProvider.class,
                 } );
                 computerCraft_registerPocketUpgrade = findCCMethod( "registerPocketUpgrade", new Class<?>[] {
-                    IPocketUpgrade.class
+                    IPocketUpgrade.class,
                 } );
                 computerCraft_getWirelessNetwork = findCCMethod( "getWirelessNetwork", new Class<?>[] {
                 } );
                 computerCraft_registerAPIFactory = findCCMethod( "registerAPIFactory", new Class<?>[] {
-                    ILuaAPIFactory.class
+                    ILuaAPIFactory.class,
                 } );
                 computerCraft_createWiredNodeForElement = findCCMethod( "createWiredNodeForElement", new Class<?>[] {
-                    IWiredElement.class
+                    IWiredElement.class,
                 } );
                 computerCraft_getWiredElementAt = findCCMethod( "getWiredElementAt", new Class<?>[] {
-                    IBlockAccess.class, BlockPos.class, EnumFacing.class
+                    IBlockAccess.class, BlockPos.class, EnumFacing.class,
                 } );
             }
             catch( Exception e )
             {
-                System.out.println( "ComputerCraftAPI: ComputerCraft not found." );
+                System.err.println( "ComputerCraftAPI: ComputerCraft not found." );
             }
             finally
             {
@@ -498,7 +498,7 @@ public final class ComputerCraftAPI
         }
         catch( NoSuchMethodException e )
         {
-            System.out.println( "ComputerCraftAPI: ComputerCraft method " + name + " not found." );
+            System.err.println( "ComputerCraftAPI: ComputerCraft method " + name + " not found." );
             return null;
         }
     }

src/main/java/dan200/computercraft/api/filesystem/FileOperationException.java

@@ -0,0 +1,41 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2019. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.filesystem;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.io.IOException;
+import java.util.Objects;
+
+/**
+ * An {@link IOException} which occurred on a specific file.
+ *
+ * This may be thrown from a {@link IMount} or {@link IWritableMount} to give more information about a failure.
+ */
+public class FileOperationException extends IOException
+{
+    private static final long serialVersionUID = -8809108200853029849L;
+
+    private final String filename;
+
+    public FileOperationException( @Nullable String filename, @Nonnull String message )
+    {
+        super( Objects.requireNonNull( message, "message cannot be null" ) );
+        this.filename = filename;
+    }
+
+    public FileOperationException( String message )
+    {
+        super( Objects.requireNonNull( message, "message cannot be null" ) );
+        this.filename = null;
+    }
+
+    @Nullable
+    public String getFilename()
+    {
+        return filename;
+    }
+}

src/main/java/dan200/computercraft/api/filesystem/IMount.java

@@ -90,7 +90,6 @@ public interface IMount
      * @throws IOException If the file does not exist, or could not be opened.
      */
     @Nonnull
-    @SuppressWarnings( "deprecation" )
     default ReadableByteChannel openChannelForRead( @Nonnull String path ) throws IOException
     {
         return Channels.newChannel( openForRead( path ) );

src/main/java/dan200/computercraft/api/filesystem/IWritableMount.java

@@ -67,7 +67,6 @@ public interface IWritableMount extends IMount
      * @throws IOException If the file could not be opened for writing.
      */
     @Nonnull
-    @SuppressWarnings( "deprecation" )
     default WritableByteChannel openChannelForWrite( @Nonnull String path ) throws IOException
     {
         return Channels.newChannel( openForWrite( path ) );
@@ -94,7 +93,6 @@ public interface IWritableMount extends IMount
      * @throws IOException If the file could not be opened for writing.
      */
     @Nonnull
-    @SuppressWarnings( "deprecation" )
     default WritableByteChannel openChannelForAppend( @Nonnull String path ) throws IOException
     {
         return Channels.newChannel( openForAppend( path ) );

src/main/java/dan200/computercraft/api/lua/ILuaAPIFactory.java

@@ -17,6 +17,7 @@ import javax.annotation.Nullable;
  * @see ILuaAPI
  * @see ComputerCraftAPI#registerAPIFactory(ILuaAPIFactory)
  */
+@FunctionalInterface
 public interface ILuaAPIFactory
 {
     /**

src/main/java/dan200/computercraft/api/lua/ILuaContext.java

@@ -32,7 +32,12 @@ public interface ILuaContext
      *                              intercepted, or the computer will leak memory and end up in a broken state.
      */
     @Nonnull
-    Object[] pullEvent( @Nullable String filter ) throws LuaException, InterruptedException;
+    default Object[] pullEvent( @Nullable String filter ) throws LuaException, InterruptedException
+    {
+        Object[] results = pullEventRaw( filter );
+        if( results.length >= 1 && results[0].equals( "terminate" ) ) throw new LuaException( "Terminated", 0 );
+        return results;
+    }
 
     /**
      * The same as {@link #pullEvent(String)}, except "terminated" events are ignored. Only use this if you want to
@@ -47,7 +52,10 @@ public interface ILuaContext
      * @see #pullEvent(String)
      */
     @Nonnull
-    Object[] pullEventRaw( @Nullable String filter ) throws InterruptedException;
+    default Object[] pullEventRaw( @Nullable String filter ) throws InterruptedException
+    {
+        return yield( new Object[] { filter } );
+    }
 
     /**
      * Yield the current coroutine with some arguments until it is resumed. This method is exactly equivalent to

src/main/java/dan200/computercraft/api/media/IMedia.java

@@ -7,6 +7,7 @@
 package dan200.computercraft.api.media;
 
 import dan200.computercraft.api.filesystem.IMount;
+import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.SoundEvent;
 import net.minecraft.world.World;
@@ -16,7 +17,9 @@ import javax.annotation.Nullable;
 
 /**
  * Represents an item that can be placed in a disk drive and used by a Computer.
- * Implement this interface on your Item class to allow it to be used in the drive.
+ *
+ * Implement this interface on your {@link Item} class to allow it to be used in the drive. Alternatively, register
+ * a {@link IMediaProvider}.
  */
 public interface IMedia
 {
@@ -43,7 +46,7 @@ public interface IMedia
 
     /**
      * If this disk represents an item with audio (like a record), get the readable name of the audio track. ie:
-     * "Jonathon Coulton - Still Alive"
+     * "Jonathan Coulton - Still Alive"
      *
      * @param stack The {@link ItemStack} to modify.
      * @return The name, or null if this item does not represent an item with audio.
@@ -74,7 +77,7 @@ public interface IMedia
      * @param world The world in which the item and disk drive reside.
      * @return The mount, or null if this item does not represent an item with data. If the mount returned also
      * implements {@link dan200.computercraft.api.filesystem.IWritableMount}, it will mounted using mountWritable()
-     * @see dan200.computercraft.api.filesystem.IMount
+     * @see IMount
      * @see dan200.computercraft.api.filesystem.IWritableMount
      * @see dan200.computercraft.api.ComputerCraftAPI#createSaveDirMount(World, String, long)
      * @see dan200.computercraft.api.ComputerCraftAPI#createResourceMount(Class, String, String)

src/main/java/dan200/computercraft/api/media/IMediaProvider.java

@@ -23,7 +23,7 @@ public interface IMediaProvider
      * Produce an IMedia implementation from an ItemStack.
      *
      * @param stack The stack from which to extract the media information.
-     * @return An IMedia implementation, or null if the item is not something you wish to handle
+     * @return An {@link IMedia} implementation, or {@code null} if the item is not something you wish to handle
      * @see dan200.computercraft.api.ComputerCraftAPI#registerMediaProvider(IMediaProvider)
      */
     @Nullable

src/main/java/dan200/computercraft/api/peripheral/IComputerAccess.java

@@ -9,6 +9,8 @@ package dan200.computercraft.api.peripheral;
 import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.api.filesystem.IMount;
 import dan200.computercraft.api.filesystem.IWritableMount;
+import dan200.computercraft.api.lua.ILuaContext;
+import dan200.computercraft.api.lua.ILuaTask;
 import net.minecraft.world.World;
 
 import javax.annotation.Nonnull;
@@ -146,7 +148,7 @@ public interface IComputerAccess
      *
      *                  You may supply {@code null} to indicate that no arguments are to be supplied.
      * @throws RuntimeException If the peripheral has been detached.
-     * @see dan200.computercraft.api.peripheral.IPeripheral#callMethod
+     * @see IPeripheral#callMethod
      */
     void queueEvent( @Nonnull String event, @Nullable Object[] arguments );
 
@@ -179,8 +181,8 @@ public interface IComputerAccess
     }
 
     /**
-     * Get a reachable peripheral with the given attachement name. This is a equivalent to
-     * {@link #getAvailablePeripherals()}{@code .get(name)}, though may be more performant.
+     * Get a reachable peripheral with the given attachment name. This is a equivalent to
+     * {@link #getAvailablePeripherals()}{@code .get(name)}, though may be more efficient.
      *
      * @param name The peripheral's attached name
      * @return The reachable peripheral, or {@code null} if none can be found.
@@ -191,4 +193,23 @@ public interface IComputerAccess
     {
         return null;
     }
+
+    /**
+     * Get a {@link IWorkMonitor} for tasks your peripheral might execute on the main (server) thread.
+     *
+     * This should be used to ensure your peripheral integrates with ComputerCraft's monitoring and limiting of how much
+     * server time each computer consumes. You should not need to use this if you use
+     * {@link ILuaContext#issueMainThreadTask(ILuaTask)} - this is intended for mods with their own system for running
+     * work on the main thread.
+     *
+     * Please note that the returned implementation is <em>not</em> thread-safe, and should only be used from the main
+     * thread.
+     *
+     * @return The work monitor for the main thread, or {@code null} if this computer does not have one.
+     */
+    @Nullable
+    default IWorkMonitor getMainThreadMonitor()
+    {
+        return null;
+    }
 }

src/main/java/dan200/computercraft/api/peripheral/IPeripheral.java

@@ -41,8 +41,8 @@ public interface IPeripheral
      * This is called when a lua program on an attached computer calls {@code peripheral.call()} with
      * one of the methods exposed by {@link #getMethodNames()}.
      *
-     * Be aware that this will be called from the ComputerCraft Lua thread, and must be thread-safe
-     * when interacting with Minecraft objects.
+     * Be aware that this will be called from the ComputerCraft Lua thread, and must be thread-safe when interacting
+     * with Minecraft objects.
      *
      * @param computer  The interface to the computer that is making the call. Remember that multiple
      *                  computers can be attached to a peripheral at once.
@@ -75,20 +75,21 @@ public interface IPeripheral
     Object[] callMethod( @Nonnull IComputerAccess computer, @Nonnull ILuaContext context, int method, @Nonnull Object[] arguments ) throws LuaException, InterruptedException;
 
     /**
-     * Is called when canAttachToSide has returned true, and a computer is attaching to the peripheral.
+     * Is called when when a computer is attaching to the peripheral.
      *
      * This will occur when a peripheral is placed next to an active computer, when a computer is turned on next to a
-     * peripheral, or when a turtle travels into a square next to a peripheral.
+     * peripheral, when a turtle travels into a square next to a peripheral, or when a wired modem adjacent to this
+     * peripheral is does any of the above.
      *
-     * Between calls to attach() and detach(), the attached computer can make method calls on the peripheral using
+     * Between calls to attach and {@link #detach}, the attached computer can make method calls on the peripheral using
      * {@code peripheral.call()}. This method can be used to keep track of which computers are attached to the
      * peripheral, or to take action when attachment occurs.
      *
-     * Be aware that this will be called from the ComputerCraft Lua thread, and must be thread-safe
-     * when interacting with Minecraft objects.
+     * Be aware that will be called from both the server thread and ComputerCraft Lua thread, and so must be thread-safe
+     * and reentrant.
      *
-     * @param computer The interface to the computer that is being attached. Remember that multiple
-     *                 computers can be attached to a peripheral at once.
+     * @param computer The interface to the computer that is being attached. Remember that multiple computers can be
+     *                 attached to a peripheral at once.
      * @see #detach
      */
     default void attach( @Nonnull IComputerAccess computer )
@@ -96,19 +97,21 @@ public interface IPeripheral
     }
 
     /**
-     * Is called when a computer is detaching from the peripheral.
+     * Called when a computer is detaching from the peripheral.
      *
-     * This will occur when a computer shuts down, when the peripheral is removed while attached to computers,
-     * or when a turtle moves away from a square attached to a peripheral. This method can be used to keep track of
-     * which computers are attached to the peripheral, or to take action when detachment
-     * occurs.
+     * This will occur when a computer shuts down, when the peripheral is removed while attached to computers, when a
+     * turtle moves away from a block attached to a peripheral, or when a wired modem adjacent to this peripheral is
+     * detached.
      *
-     * Be aware that this will be called from the ComputerCraft Lua thread, and must be thread-safe
-     * when interacting with Minecraft objects.
+     * This method can be used to keep track of which computers are attached to the peripheral, or to take action when
+     * detachment occurs.
      *
-     * @param computer The interface to the computer that is being detached. Remember that multiple
-     *                 computers can be attached to a peripheral at once.
-     * @see #detach
+     * Be aware that this will be called from both the server and ComputerCraft Lua thread, and must be thread-safe
+     * and reentrant.
+     *
+     * @param computer The interface to the computer that is being detached. Remember that multiple computers can be
+     *                 attached to a peripheral at once.
+     * @see #attach
      */
     default void detach( @Nonnull IComputerAccess computer )
     {

src/main/java/dan200/computercraft/api/peripheral/IPeripheralProvider.java

@@ -6,6 +6,7 @@
 
 package dan200.computercraft.api.peripheral;
 
+import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.EnumFacing;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.World;
@@ -16,6 +17,8 @@ import javax.annotation.Nullable;
 /**
  * This interface is used to create peripheral implementations for blocks.
  *
+ * If you have a {@link TileEntity} which acts as a peripheral, you may alternatively implement {@link IPeripheralTile}.
+ *
  * @see dan200.computercraft.api.ComputerCraftAPI#registerPeripheralProvider(IPeripheralProvider)
  */
 @FunctionalInterface

src/main/java/dan200/computercraft/api/peripheral/IPeripheralTile.java

@@ -0,0 +1,32 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2019. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.peripheral;
+
+import net.minecraft.util.EnumFacing;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.world.World;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+/**
+ * A {@link net.minecraft.tileentity.TileEntity} which may act as a peripheral.
+ *
+ * If you need more complex capabilities (such as handling TEs not belonging to your mod), you should use
+ * {@link IPeripheralProvider}.
+ */
+public interface IPeripheralTile
+{
+    /**
+     * Get the peripheral on the given {@code side}.
+     *
+     * @param side The side to get the peripheral from.
+     * @return A peripheral, or {@code null} if there is not a peripheral here.
+     * @see IPeripheralProvider#getPeripheral(World, BlockPos, EnumFacing)
+     */
+    @Nullable
+    IPeripheral getPeripheral( @Nonnull EnumFacing side );
+}

src/main/java/dan200/computercraft/api/peripheral/IWorkMonitor.java

@@ -0,0 +1,77 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2019. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.peripheral;
+
+import javax.annotation.Nonnull;
+import java.util.Objects;
+import java.util.concurrent.TimeUnit;
+
+/**
+ * Monitors "work" associated with a computer, keeping track of how much a computer has done, and ensuring every
+ * computer receives a fair share of any processing time.
+ *
+ * This is primarily intended for work done by peripherals on the main thread (such as on a tile entity's tick), but
+ * could be used for other purposes (such as complex computations done on another thread).
+ *
+ * Before running a task, one should call {@link #canWork()} to determine if the computer is currently allowed to
+ * execute work. If that returns true, you should execute the task and use {@link #trackWork(long, TimeUnit)} to inform
+ * the monitor how long that task took.
+ *
+ * Alternatively, use {@link #runWork(Runnable)} to run and keep track of work.
+ *
+ * @see IComputerAccess#getMainThreadMonitor()
+ */
+public interface IWorkMonitor
+{
+    /**
+     * If the owning computer is currently allowed to execute work.
+     *
+     * @return If we can execute work right now.
+     */
+    boolean canWork();
+
+    /**
+     * If the owning computer is currently allowed to execute work, and has ample time to do so.
+     *
+     * This is effectively a more restrictive form of {@link #canWork()}. One should use that in order to determine if
+     * you may do an initial piece of work, and shouldWork to determine if any additional task may be performed.
+     *
+     * @return If we should execute work right now.
+     */
+    boolean shouldWork();
+
+    /**
+     * Inform the monitor how long some piece of work took to execute.
+     *
+     * @param time The time some task took to run
+     * @param unit The unit that {@code time} was measured in.
+     */
+    void trackWork( long time, @Nonnull TimeUnit unit );
+
+    /**
+     * Run a task if possible, and inform the monitor of how long it took.
+     *
+     * @param runnable The task to run.
+     * @return If the task was actually run (namely, {@link #canWork()} returned {@code true}).
+     */
+    default boolean runWork( @Nonnull Runnable runnable )
+    {
+        Objects.requireNonNull( runnable, "runnable should not be null" );
+        if( !canWork() ) return false;
+
+        long start = System.nanoTime();
+        try
+        {
+            runnable.run();
+        }
+        finally
+        {
+            trackWork( System.nanoTime() - start, TimeUnit.NANOSECONDS );
+        }
+
+        return true;
+    }
+}

src/main/java/dan200/computercraft/api/pocket/AbstractPocketUpgrade.java

@@ -1,17 +1,20 @@
 /*
- * This file is part of ComputerCraft - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2019. Do not distribute without permission.
- * Send enquiries to dratcliffe@gmail.com
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2019. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
  */
+package dan200.computercraft.api.pocket;
 
-package dan200.computercraft.shared.pocket.peripherals;
-
-import dan200.computercraft.api.pocket.IPocketUpgrade;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.ResourceLocation;
 
 import javax.annotation.Nonnull;
 
+/**
+ * A base class for {@link IPocketUpgrade}s.
+ *
+ * One does not have to use this, but it does provide a convenient template.
+ */
 public abstract class AbstractPocketUpgrade implements IPocketUpgrade
 {
     private final ResourceLocation id;
@@ -25,6 +28,11 @@ public abstract class AbstractPocketUpgrade implements IPocketUpgrade
         this.stack = stack;
     }
 
+    protected AbstractPocketUpgrade( ResourceLocation id, ItemStack stack )
+    {
+        this( id, "upgrade." + id + ".adjective", stack );
+    }
+
     @Nonnull
     @Override
     public final ResourceLocation getUpgradeID()

src/main/java/dan200/computercraft/api/pocket/IPocketAccess.java

@@ -24,10 +24,22 @@ public interface IPocketAccess
      * Gets the entity holding this item.
      *
      * @return The holding entity. This may be {@code null}.
+     * @deprecated Use {@link #getValidEntity()} where possible.
      */
     @Nullable
+    @Deprecated
     Entity getEntity();
 
+    /**
+     * Gets the entity holding this item with additional safety checks.
+     *
+     * This must be called on the server thread.
+     *
+     * @return The holding entity, or {@code null} if none exists.
+     */
+    @Nullable
+    Entity getValidEntity();
+
     /**
      * Get the colour of this pocket computer as a RGB number.
      *

src/main/java/dan200/computercraft/api/pocket/IPocketUpgrade.java

@@ -19,7 +19,7 @@ import javax.annotation.Nullable;
 /**
  * Additional peripherals for pocket computers.
  *
- * This is similar to {@link dan200.computercraft.api.turtle.ITurtleUpgrade}.
+ * This is similar to {@link ITurtleUpgrade}.
  */
 public interface IPocketUpgrade
 {
@@ -54,6 +54,9 @@ public interface IPocketUpgrade
      * pocket computer which holds this upgrade. This item stack is also used to determine the upgrade given by
      * {@code pocket.equip()}/{@code pocket.unequip()}.
      *
+     * Ideally this should be constant over a session. It is recommended that you cache
+     * the item too, in order to prevent constructing it every time the method is called.
+     *
      * @return The item stack used for crafting. This can be {@link ItemStack#EMPTY} if crafting is disabled.
      */
     @Nonnull

src/main/java/dan200/computercraft/api/turtle/ITurtleAccess.java

@@ -145,7 +145,9 @@ public interface ITurtleAccess
     GameProfile getOwningPlayer();
 
     /**
-     * Get the inventory of this turtle
+     * Get the inventory of this turtle.
+     *
+     * Note: this inventory should only be accessed and modified on the server thread.
      *
      * @return This turtle's inventory
      * @see #getItemHandler()
@@ -156,6 +158,8 @@ public interface ITurtleAccess
     /**
      * Get the inventory of this turtle as an {@link IItemHandlerModifiable}.
      *
+     * Note: this inventory should only be accessed and modified on the server thread.
+     *
      * @return This turtle's inventory
      * @see #getInventory()
      * @see IItemHandlerModifiable

src/main/java/dan200/computercraft/api/turtle/ITurtleUpgrade.java

@@ -79,6 +79,9 @@ public interface ITurtleUpgrade
      * with to create a turtle which holds this upgrade. This item stack is also used
      * to determine the upgrade given by {@code turtle.equip()}
      *
+     * Ideally this should be constant over a session. It is recommended that you cache
+     * the item too, in order to prevent constructing it every time the method is called.
+     *
      * @return The item stack to craft with, or {@link ItemStack#EMPTY} if it cannot be crafted.
      */
     @Nonnull
@@ -106,8 +109,8 @@ public interface ITurtleUpgrade
      * Will only be called for Tool turtle. Called when turtle.dig() or turtle.attack() is called
      * by the turtle, and the tool is required to do some work.
      *
-     * Conforming implementations should fire {@link BlockEvent.BreakEvent} and {@link TurtleBlockEvent.Dig}for digging,
-     * {@link AttackEntityEvent} and {@link TurtleAttackEvent} for attacking.
+     * Conforming implementations should fire {@link BlockEvent.BreakEvent} and {@link TurtleBlockEvent.Dig} for
+     * digging, {@link AttackEntityEvent} and {@link TurtleAttackEvent} for attacking.
      *
      * @param turtle    Access to the turtle that the tool resides on.
      * @param side      Which side of the turtle (left or right) the tool resides on.

src/main/java/dan200/computercraft/api/turtle/event/TurtleBlockEvent.java

@@ -19,7 +19,6 @@ import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.World;
 import net.minecraftforge.common.util.FakePlayer;
 import net.minecraftforge.event.world.BlockEvent;
-import net.minecraftforge.fml.common.eventhandler.Cancelable;
 
 import javax.annotation.Nonnull;
 import java.util.Map;
@@ -37,7 +36,6 @@ import java.util.Objects;
  * Be aware that some events (such as {@link TurtleInventoryEvent}) do not necessarily interact
  * with a block, simply objects within that block space.
  */
-@Cancelable
 public abstract class TurtleBlockEvent extends TurtlePlayerEvent
 {
     private final World world;
@@ -84,7 +82,6 @@ public abstract class TurtleBlockEvent extends TurtlePlayerEvent
      *
      * @see TurtleAction#DIG
      */
-    @Cancelable
     public static class Dig extends TurtleBlockEvent
     {
         private final IBlockState block;
@@ -142,7 +139,6 @@ public abstract class TurtleBlockEvent extends TurtlePlayerEvent
      *
      * @see TurtleAction#MOVE
      */
-    @Cancelable
     public static class Move extends TurtleBlockEvent
     {
         public Move( @Nonnull ITurtleAccess turtle, @Nonnull FakePlayer player, @Nonnull World world, @Nonnull BlockPos pos )
@@ -156,7 +152,6 @@ public abstract class TurtleBlockEvent extends TurtlePlayerEvent
      *
      * @see TurtleAction#PLACE
      */
-    @Cancelable
     public static class Place extends TurtleBlockEvent
     {
         private final ItemStack stack;
@@ -188,7 +183,6 @@ public abstract class TurtleBlockEvent extends TurtlePlayerEvent
      *
      * @see TurtleAction#INSPECT
      */
-    @Cancelable
     public static class Inspect extends TurtleBlockEvent
     {
         private final IBlockState state;
@@ -229,7 +223,7 @@ public abstract class TurtleBlockEvent extends TurtlePlayerEvent
         /**
          * Add new information to the inspection result. Note this will override fields with the same name.
          *
-         * @param newData The data to add. Note all values should be convertable to Lua (see
+         * @param newData The data to add. Note all values should be convertible to Lua (see
          *                {@link dan200.computercraft.api.peripheral.IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])}).
          */
         public void addData( @Nonnull Map<String, ?> newData )

src/main/java/dan200/computercraft/api/turtle/event/TurtleInspectItemEvent.java

@@ -0,0 +1,73 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2019. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.turtle.event;
+
+import dan200.computercraft.api.lua.ILuaContext;
+import dan200.computercraft.api.peripheral.IComputerAccess;
+import dan200.computercraft.api.turtle.ITurtleAccess;
+import net.minecraft.item.ItemStack;
+
+import javax.annotation.Nonnull;
+import java.util.Map;
+import java.util.Objects;
+
+/**
+ * Fired when a turtle gathers data on an item in its inventory.
+ *
+ * You may prevent items being inspected, or add additional information to the result. Be aware that this is fired on
+ * the computer thread, and so any operations on it must be thread safe.
+ *
+ * @see TurtleAction#INSPECT_ITEM
+ */
+public class TurtleInspectItemEvent extends TurtleActionEvent
+{
+    private final ItemStack stack;
+    private final Map<String, Object> data;
+
+    public TurtleInspectItemEvent( @Nonnull ITurtleAccess turtle, @Nonnull ItemStack stack, @Nonnull Map<String, Object> data )
+    {
+        super( turtle, TurtleAction.INSPECT_ITEM );
+
+        Objects.requireNonNull( stack, "stack cannot be null" );
+        Objects.requireNonNull( data, "data cannot be null" );
+        this.stack = stack;
+        this.data = data;
+    }
+
+    /**
+     * The item which is currently being inspected.
+     *
+     * @return The item stack which is being inspected. This should <b>not</b> be modified.
+     */
+    @Nonnull
+    public ItemStack getStack()
+    {
+        return stack;
+    }
+
+    /**
+     * Get the "inspection data" from this item, which will be returned to the user.
+     *
+     * @return This items's inspection data.
+     */
+    @Nonnull
+    public Map<String, Object> getData()
+    {
+        return data;
+    }
+
+    /**
+     * Add new information to the inspection result. Note this will override fields with the same name.
+     *
+     * @param newData The data to add. Note all values should be convertible to Lua (see
+     *                {@link dan200.computercraft.api.peripheral.IPeripheral#callMethod(IComputerAccess, ILuaContext, int, Object[])}).
+     */
+    public void addData( @Nonnull Map<String, ?> newData )
+    {
+        Objects.requireNonNull( newData, "newData cannot be null" );
+        data.putAll( newData );
+    }
+}

src/main/java/dan200/computercraft/api/turtle/event/TurtleInventoryEvent.java

@@ -11,7 +11,6 @@ import net.minecraft.item.ItemStack;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.World;
 import net.minecraftforge.common.util.FakePlayer;
-import net.minecraftforge.fml.common.eventhandler.Cancelable;
 import net.minecraftforge.items.IItemHandler;
 
 import javax.annotation.Nonnull;
@@ -21,7 +20,6 @@ import java.util.Objects;
 /**
  * Fired when a turtle attempts to interact with an inventory.
  */
-@Cancelable
 public abstract class TurtleInventoryEvent extends TurtleBlockEvent
 {
     private final IItemHandler handler;
@@ -48,7 +46,6 @@ public abstract class TurtleInventoryEvent extends TurtleBlockEvent
      *
      * @see TurtleAction#SUCK
      */
-    @Cancelable
     public static class Suck extends TurtleInventoryEvent
     {
         public Suck( @Nonnull ITurtleAccess turtle, @Nonnull FakePlayer player, @Nonnull World world, @Nonnull BlockPos pos, @Nullable IItemHandler handler )
@@ -62,7 +59,6 @@ public abstract class TurtleInventoryEvent extends TurtleBlockEvent
      *
      * @see TurtleAction#DROP
      */
-    @Cancelable
     public static class Drop extends TurtleInventoryEvent
     {
         private final ItemStack stack;
@@ -78,13 +74,12 @@ public abstract class TurtleInventoryEvent extends TurtleBlockEvent
         /**
          * The item which will be inserted into the inventory/dropped on the ground.
          *
-         * Note that this is a copy of the original stack, and so should not be modified, as that will have no effect.
-         *
-         * @return The item stack which will be dropped.
+         * @return The item stack which will be dropped. This should <b>not</b> be modified.
          */
+        @Nonnull
         public ItemStack getStack()
         {
-            return stack.copy();
+            return stack;
         }
     }
 }

src/main/java/dan200/computercraft/api/turtle/event/TurtleRefuelEvent.java

@@ -0,0 +1,90 @@
+/*
+ * This file is part of the public ComputerCraft API - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2019. This API may be redistributed unmodified and in full only.
+ * For help using the API, and posting your mods, visit the forums at computercraft.info.
+ */
+package dan200.computercraft.api.turtle.event;
+
+import dan200.computercraft.api.turtle.ITurtleAccess;
+import net.minecraft.item.ItemStack;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.util.Objects;
+
+/**
+ * Fired when a turtle attempts to refuel from an item.
+ *
+ * One may use {@link #setCanceled(boolean, String)} to prevent refueling from this specific item. Additionally, you
+ * may use {@link #setHandler(Handler)} to register a custom fuel provider.
+ */
+public class TurtleRefuelEvent extends TurtleActionEvent
+{
+    private final ItemStack stack;
+    private Handler handler;
+
+    public TurtleRefuelEvent( @Nonnull ITurtleAccess turtle, @Nonnull ItemStack stack )
+    {
+        super( turtle, TurtleAction.REFUEL );
+
+        Objects.requireNonNull( turtle, "turtle cannot be null" );
+        this.stack = stack;
+    }
+
+    /**
+     * Get the stack we are attempting to refuel from.
+     *
+     * Do not modify the returned stack - all modifications should be done within the {@link Handler}.
+     *
+     * @return The stack to refuel from.
+     */
+    public ItemStack getStack()
+    {
+        return stack;
+    }
+
+    /**
+     * Get the refuel handler for this stack.
+     *
+     * @return The refuel handler, or {@code null} if none has currently been set.
+     * @see #setHandler(Handler)
+     */
+    @Nullable
+    public Handler getHandler()
+    {
+        return handler;
+    }
+
+    /**
+     * Set the refuel handler for this stack.
+     *
+     * You should call this if you can actually refuel from this item, and ideally only if there are no existing
+     * handlers.
+     *
+     * @param handler The new refuel handler.
+     * @see #getHandler()
+     */
+    public void setHandler( @Nullable Handler handler )
+    {
+        this.handler = handler;
+    }
+
+    /**
+     * Handles refuelling a turtle from a specific item.
+     */
+    @FunctionalInterface
+    public interface Handler
+    {
+        /**
+         * Refuel a turtle using an item.
+         *
+         * @param turtle The turtle to refuel.
+         * @param stack  The stack to refuel with.
+         * @param slot   The slot the stack resides within. This may be used to modify the inventory afterwards.
+         * @param limit  The maximum number of refuel operations to perform. This will often correspond to the number of
+         *               items to consume.
+         * @return The amount of fuel gained.
+         */
+        int refuel( @Nonnull ITurtleAccess turtle, @Nonnull ItemStack stack, int slot, int limit );
+    }
+}

src/main/java/dan200/computercraft/client/ClientRegistry.java

@@ -0,0 +1,185 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2019. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.client;
+
+import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.client.render.TurtleModelLoader;
+import dan200.computercraft.shared.media.items.ItemDiskLegacy;
+import dan200.computercraft.shared.pocket.items.ItemPocketComputer;
+import dan200.computercraft.shared.turtle.items.ItemTurtleBase;
+import dan200.computercraft.shared.util.Colour;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.renderer.ItemMeshDefinition;
+import net.minecraft.client.renderer.block.model.IBakedModel;
+import net.minecraft.client.renderer.block.model.ModelBakery;
+import net.minecraft.client.renderer.block.model.ModelResourceLocation;
+import net.minecraft.client.renderer.texture.TextureMap;
+import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
+import net.minecraft.item.Item;
+import net.minecraft.item.ItemStack;
+import net.minecraft.util.ResourceLocation;
+import net.minecraftforge.client.event.ColorHandlerEvent;
+import net.minecraftforge.client.event.ModelBakeEvent;
+import net.minecraftforge.client.event.ModelRegistryEvent;
+import net.minecraftforge.client.event.TextureStitchEvent;
+import net.minecraftforge.client.model.IModel;
+import net.minecraftforge.client.model.ModelLoader;
+import net.minecraftforge.client.model.ModelLoaderRegistry;
+import net.minecraftforge.fml.common.Mod;
+import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
+import net.minecraftforge.fml.relauncher.Side;
+
+import javax.annotation.Nonnull;
+
+/**
+ * Registers textures and models for items.
+ */
+@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Side.CLIENT )
+public final class ClientRegistry
+{
+    private static final String[] EXTRA_MODELS = new String[] {
+        "turtle_modem_off_left",
+        "turtle_modem_on_left",
+        "turtle_modem_off_right",
+        "turtle_modem_on_right",
+        "turtle_crafting_table_left",
+        "turtle_crafting_table_right",
+        "advanced_turtle_modem_off_left",
+        "advanced_turtle_modem_on_left",
+        "advanced_turtle_modem_off_right",
+        "advanced_turtle_modem_on_right",
+        "turtle_speaker_upgrade_left",
+        "turtle_speaker_upgrade_right",
+
+        "turtle_white",
+        "turtle_elf_overlay",
+    };
+
+    private ClientRegistry() {}
+
+    @SubscribeEvent
+    public static void registerModels( ModelRegistryEvent event )
+    {
+        ModelLoaderRegistry.registerLoader( TurtleModelLoader.INSTANCE );
+
+        // Register item models
+        registerUniversalItemModel( ComputerCraft.Items.computer, "computer" );
+        registerItemModel( ComputerCraft.Items.commandComputer, 0, "command_computer" );
+
+        registerItemModel( ComputerCraft.Items.pocketComputer, 0, "pocket_computer" );
+        registerItemModel( ComputerCraft.Items.pocketComputer, 1, "advanced_pocket_computer" );
+
+        registerItemModel( ComputerCraft.Items.peripheral, 0, "peripheral" );
+        registerItemModel( ComputerCraft.Items.peripheral, 1, "wireless_modem" );
+        registerItemModel( ComputerCraft.Items.peripheral, 2, "monitor" );
+        registerItemModel( ComputerCraft.Items.peripheral, 3, "printer" );
+        registerItemModel( ComputerCraft.Items.peripheral, 4, "advanced_monitor" );
+        registerItemModel( ComputerCraft.Items.cable, 0, "cable" );
+        registerItemModel( ComputerCraft.Items.cable, 1, "wired_modem" );
+        registerItemModel( ComputerCraft.Items.advancedModem, 0, "advanced_modem" );
+        registerItemModel( ComputerCraft.Items.peripheral, 5, "speaker" );
+        registerItemModel( ComputerCraft.Items.wiredModemFull, 0, "wired_modem_full" );
+
+        registerUniversalItemModel( ComputerCraft.Items.disk, "disk" );
+        registerItemModel( ComputerCraft.Items.diskExpanded, 0, "disk_expanded" );
+        registerItemModel( ComputerCraft.Items.treasureDisk, 0, "treasure_disk" );
+
+        registerItemModel( ComputerCraft.Items.printout, 0, "printout" );
+        registerItemModel( ComputerCraft.Items.printout, 1, "pages" );
+        registerItemModel( ComputerCraft.Items.printout, 2, "book" );
+
+        registerUniversalItemModel( ComputerCraft.Items.turtle, "turtle" );
+        registerUniversalItemModel( ComputerCraft.Items.turtleExpanded, "turtle" );
+        registerUniversalItemModel( ComputerCraft.Items.turtleAdvanced, "turtle_advanced" );
+    }
+
+    @SubscribeEvent
+    public static void onTextureStitchEvent( TextureStitchEvent.Pre event )
+    {
+        // Load all textures for the extra models
+        TextureMap map = event.getMap();
+        for( String upgrade : EXTRA_MODELS )
+        {
+            IModel model = ModelLoaderRegistry.getModelOrMissing( new ResourceLocation( "computercraft", "block/" + upgrade ) );
+            for( ResourceLocation texture : model.getTextures() ) map.registerSprite( texture );
+        }
+    }
+
+    @SubscribeEvent
+    public static void onModelBakeEvent( ModelBakeEvent event )
+    {
+        // Load all extra models
+        for( String model : EXTRA_MODELS ) loadBlockModel( event, model );
+    }
+
+    @SubscribeEvent
+    public static void onItemColours( ColorHandlerEvent.Item event )
+    {
+        event.getItemColors().registerItemColorHandler(
+            ( stack, layer ) -> layer == 1 ? ((ItemDiskLegacy) stack.getItem()).getColour( stack ) : 0xFFFFFF,
+            ComputerCraft.Items.disk, ComputerCraft.Items.diskExpanded
+        );
+
+        event.getItemColors().registerItemColorHandler( ( stack, layer ) -> {
+            switch( layer )
+            {
+                case 0:
+                default:
+                    return 0xFFFFFF;
+                case 1: // Frame colour
+                    return ComputerCraft.Items.pocketComputer.getColour( stack );
+                case 2: // Light colour
+                {
+                    int light = ItemPocketComputer.getLightState( stack );
+                    return light == -1 ? Colour.Black.getHex() : light;
+                }
+            }
+        }, ComputerCraft.Items.pocketComputer );
+
+        // Setup turtle colours
+        event.getItemColors().registerItemColorHandler(
+            ( stack, tintIndex ) -> tintIndex == 0 ? ((ItemTurtleBase) stack.getItem()).getColour( stack ) : 0xFFFFFF,
+            ComputerCraft.Blocks.turtle, ComputerCraft.Blocks.turtleExpanded, ComputerCraft.Blocks.turtleAdvanced
+        );
+    }
+
+    private static void registerItemModel( Item item, int damage, String name )
+    {
+        ResourceLocation location = new ResourceLocation( ComputerCraft.MOD_ID, name );
+        final ModelResourceLocation res = new ModelResourceLocation( location, "inventory" );
+        ModelBakery.registerItemVariants( item, location );
+        ModelLoader.setCustomModelResourceLocation( item, damage, res );
+    }
+
+    private static void registerUniversalItemModel( Item item, String mainModel )
+    {
+        ResourceLocation mainLocation = new ResourceLocation( ComputerCraft.MOD_ID, mainModel );
+        ModelBakery.registerItemVariants( item, mainLocation );
+
+        final ModelResourceLocation mainModelLocation = new ModelResourceLocation( mainLocation, "inventory" );
+        ModelLoader.setCustomMeshDefinition( item, new ItemMeshDefinition()
+        {
+            @Nonnull
+            @Override
+            public ModelResourceLocation getModelLocation( @Nonnull ItemStack stack )
+            {
+                return mainModelLocation;
+            }
+        } );
+    }
+
+    private static void loadBlockModel( ModelBakeEvent event, String name )
+    {
+        IModel model = ModelLoaderRegistry.getModelOrMissing( new ResourceLocation( ComputerCraft.MOD_ID, "block/" + name ) );
+        IBakedModel bakedModel = model.bake(
+            model.getDefaultState(), DefaultVertexFormats.ITEM,
+            location -> Minecraft.getMinecraft().getTextureMapBlocks().getAtlasSprite( location.toString() )
+        );
+
+        event.getModelRegistry().putObject( new ModelResourceLocation( ComputerCraft.MOD_ID + ":" + name, "inventory" ), bakedModel );
+    }
+}

src/main/java/dan200/computercraft/client/ClientTableFormatter.java

@@ -13,12 +13,14 @@ import it.unimi.dsi.fastutil.ints.Int2IntOpenHashMap;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.gui.FontRenderer;
 import net.minecraft.client.gui.GuiNewChat;
+import net.minecraft.client.gui.GuiUtilRenderComponents;
 import net.minecraft.util.math.MathHelper;
 import net.minecraft.util.text.ITextComponent;
 import net.minecraft.util.text.TextFormatting;
 import org.apache.commons.lang3.StringUtils;
 
 import javax.annotation.Nullable;
+import java.util.List;
 
 public class ClientTableFormatter implements TableFormatter
 {
@@ -26,7 +28,7 @@ public class ClientTableFormatter implements TableFormatter
 
     private static Int2IntOpenHashMap lastHeights = new Int2IntOpenHashMap();
 
-    private FontRenderer renderer()
+    private static FontRenderer renderer()
     {
         return Minecraft.getMinecraft().fontRenderer;
     }
@@ -62,7 +64,13 @@ public class ClientTableFormatter implements TableFormatter
     @Override
     public void writeLine( int id, ITextComponent component )
     {
-        Minecraft.getMinecraft().ingameGUI.getChatGUI().printChatMessageWithOptionalDeletion( component, id );
+        Minecraft mc = Minecraft.getMinecraft();
+        GuiNewChat chat = mc.ingameGUI.getChatGUI();
+
+        // Trim the text if it goes over the allowed length
+        int maxWidth = MathHelper.floor( chat.getChatWidth() / chat.getChatScale() );
+        List<ITextComponent> list = GuiUtilRenderComponents.splitText( component, maxWidth, mc.fontRenderer, false, false );
+        if( !list.isEmpty() ) chat.printChatMessageWithOptionalDeletion( list.get( 0 ), id );
     }
 
     @Override

src/main/java/dan200/computercraft/client/FrameInfo.java

@@ -6,43 +6,40 @@
 
 package dan200.computercraft.client;
 
+import dan200.computercraft.ComputerCraft;
+import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
 import net.minecraftforge.fml.common.gameevent.TickEvent;
+import net.minecraftforge.fml.relauncher.Side;
 
-public class FrameInfo
+@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Side.CLIENT )
+public final class FrameInfo
 {
-    private static final FrameInfo instance = new FrameInfo();
-
-    public static FrameInfo instance()
-    {
-        return instance;
-    }
-
-    private int tick;
-    private long renderFrame;
+    private static int tick;
+    private static long renderFrame;
 
     private FrameInfo()
     {
     }
 
-    public boolean getGlobalCursorBlink()
+    public static boolean getGlobalCursorBlink()
     {
         return (tick / 8) % 2 == 0;
     }
 
-    public long getRenderFrame()
+    public static long getRenderFrame()
     {
         return renderFrame;
     }
 
     @SubscribeEvent
-    public void onTick( TickEvent.ClientTickEvent event )
+    public static void onTick( TickEvent.ClientTickEvent event )
     {
         if( event.phase == TickEvent.Phase.START ) tick++;
     }
 
     @SubscribeEvent
-    public void onRenderTick( TickEvent.RenderTickEvent event )
+    public static void onRenderTick( TickEvent.RenderTickEvent event )
     {
         if( event.phase == TickEvent.Phase.START ) renderFrame++;
     }

src/main/java/dan200/computercraft/client/gui/FixedWidthFontRenderer.java

@@ -19,7 +19,7 @@ import org.lwjgl.opengl.GL11;
 
 import java.util.Arrays;
 
-public class FixedWidthFontRenderer
+public final class FixedWidthFontRenderer
 {
     private static final ResourceLocation FONT = new ResourceLocation( "computercraft", "textures/gui/term_font.png" );
     public static final ResourceLocation BACKGROUND = new ResourceLocation( "computercraft", "textures/gui/term_background.png" );
@@ -93,7 +93,7 @@ public class FixedWidthFontRenderer
 
     private boolean isGreyScale( int colour )
     {
-        return (colour == 0 || colour == 15 || colour == 7 || colour == 8);
+        return colour == 0 || colour == 15 || colour == 7 || colour == 8;
     }
 
     public void drawStringBackgroundPart( int x, int y, TextBuffer backgroundColour, double leftMarginSize, double rightMarginSize, boolean greyScale, Palette p )

src/main/java/dan200/computercraft/client/gui/GuiComputer.java

@@ -24,9 +24,10 @@ import java.io.IOException;
 
 public class GuiComputer extends GuiContainer
 {
-    private static final ResourceLocation BACKGROUND = new ResourceLocation( "computercraft", "textures/gui/corners.png" );
-    private static final ResourceLocation BACKGROUND_ADVANCED = new ResourceLocation( "computercraft", "textures/gui/corners_advanced.png" );
-    private static final ResourceLocation BACKGROUND_COMMAND = new ResourceLocation( "computercraft", "textures/gui/corners_command.png" );
+    public static final ResourceLocation BACKGROUND_NORMAL = new ResourceLocation( ComputerCraft.MOD_ID, "textures/gui/corners.png" );
+    public static final ResourceLocation BACKGROUND_ADVANCED = new ResourceLocation( ComputerCraft.MOD_ID, "textures/gui/corners_advanced.png" );
+    public static final ResourceLocation BACKGROUND_COMMAND = new ResourceLocation( ComputerCraft.MOD_ID, "textures/gui/corners_command.png" );
+    public static final ResourceLocation BACKGROUND_COLOUR = new ResourceLocation( ComputerCraft.MOD_ID, "textures/gui/corners_colour.png" );
 
     private final ComputerFamily m_family;
     private final ClientComputer m_computer;
@@ -80,12 +81,6 @@ public class GuiComputer extends GuiContainer
         Keyboard.enableRepeatEvents( false );
     }
 
-    @Override
-    public boolean doesGuiPauseGame()
-    {
-        return false;
-    }
-
     @Override
     public void updateScreen()
     {
@@ -144,7 +139,7 @@ public class GuiComputer extends GuiContainer
     }
 
     @Override
-    public void drawScreen( int mouseX, int mouseY, float f )
+    public void drawScreen( int mouseX, int mouseY, float partialTicks )
     {
         // Work out where to draw
         int startX = (width - m_terminal.getWidth()) / 2;
@@ -156,7 +151,7 @@ public class GuiComputer extends GuiContainer
         drawDefaultBackground();
 
         // Draw terminal
-        m_terminal.draw( this.mc, startX, startY, mouseX, mouseY );
+        m_terminal.draw( mc, startX, startY, mouseX, mouseY );
 
         // Draw a border around the terminal
         GlStateManager.color( 1.0f, 1.0f, 1.0f, 1.0f );
@@ -164,29 +159,23 @@ public class GuiComputer extends GuiContainer
         {
             case Normal:
             default:
-            {
-                this.mc.getTextureManager().bindTexture( BACKGROUND );
+                mc.getTextureManager().bindTexture( BACKGROUND_NORMAL );
                 break;
-            }
             case Advanced:
-            {
-                this.mc.getTextureManager().bindTexture( BACKGROUND_ADVANCED );
+                mc.getTextureManager().bindTexture( BACKGROUND_ADVANCED );
                 break;
-            }
             case Command:
-            {
-                this.mc.getTextureManager().bindTexture( BACKGROUND_COMMAND );
+                mc.getTextureManager().bindTexture( BACKGROUND_COMMAND );
                 break;
-            }
         }
 
         drawTexturedModalRect( startX - 12, startY - 12, 12, 28, 12, 12 );
-        drawTexturedModalRect( startX - 12, endY, 12, 40, 12, 16 );
+        drawTexturedModalRect( startX - 12, endY, 12, 40, 12, 12 );
         drawTexturedModalRect( endX, startY - 12, 24, 28, 12, 12 );
-        drawTexturedModalRect( endX, endY, 24, 40, 12, 16 );
+        drawTexturedModalRect( endX, endY, 24, 40, 12, 12 );
 
         drawTexturedModalRect( startX, startY - 12, 0, 0, endX - startX, 12 );
-        drawTexturedModalRect( startX, endY, 0, 12, endX - startX, 16 );
+        drawTexturedModalRect( startX, endY, 0, 12, endX - startX, 12 );
 
         drawTexturedModalRect( startX - 12, startY, 0, 28, 12, endY - startY );
         drawTexturedModalRect( endX, startY, 36, 28, 12, endY - startY );

src/main/java/dan200/computercraft/client/gui/GuiConfigCC.java

@@ -22,10 +22,8 @@ public class GuiConfigCC extends GuiConfig
         super( parentScreen, Config.getConfigElements(), ComputerCraft.MOD_ID, false, false, "CC: Tweaked" );
     }
 
-    public static class Factory
-        implements IModGuiFactory
+    public static class Factory implements IModGuiFactory
     {
-
         @Override
         public void initialize( Minecraft minecraft )
         {

src/main/java/dan200/computercraft/client/gui/GuiDiskDrive.java

@@ -25,21 +25,19 @@ public class GuiDiskDrive extends GuiContainer
     }
 
     @Override
-    protected void drawGuiContainerForegroundLayer( int par1, int par2 )
+    protected void drawGuiContainerForegroundLayer( int mouseX, int mouseY )
     {
         String title = m_container.getDiskDrive().getDisplayName().getUnformattedText();
         fontRenderer.drawString( title, (xSize - fontRenderer.getStringWidth( title )) / 2, 6, 0x404040 );
-        fontRenderer.drawString( I18n.format( "container.inventory" ), 8, (ySize - 96) + 2, 0x404040 );
+        fontRenderer.drawString( I18n.format( "container.inventory" ), 8, ySize - 96 + 2, 0x404040 );
     }
 
     @Override
-    protected void drawGuiContainerBackgroundLayer( float f, int i, int j )
+    protected void drawGuiContainerBackgroundLayer( float partialTicks, int mouseX, int mouseY )
     {
         GlStateManager.color( 1.0F, 1.0F, 1.0F, 1.0F );
-        this.mc.getTextureManager().bindTexture( BACKGROUND );
-        int l = (width - xSize) / 2;
-        int i1 = (height - ySize) / 2;
-        drawTexturedModalRect( l, i1, 0, 0, xSize, ySize );
+        mc.getTextureManager().bindTexture( BACKGROUND );
+        drawTexturedModalRect( guiLeft, guiTop, 0, 0, xSize, ySize );
     }
 
     @Override

src/main/java/dan200/computercraft/client/gui/GuiPocketComputer.java

@@ -8,6 +8,7 @@ package dan200.computercraft.client.gui;
 
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.shared.media.inventory.ContainerHeldItem;
+import dan200.computercraft.shared.pocket.items.ItemPocketComputer;
 
 public class GuiPocketComputer extends GuiComputer
 {
@@ -16,7 +17,7 @@ public class GuiPocketComputer extends GuiComputer
         super(
             container,
             ComputerCraft.Items.pocketComputer.getFamily( container.getStack() ),
-            ComputerCraft.Items.pocketComputer.createClientComputer( container.getStack() ),
+            ItemPocketComputer.createClientComputer( container.getStack() ),
             ComputerCraft.terminalWidth_pocketComputer,
             ComputerCraft.terminalHeight_pocketComputer
         );

src/main/java/dan200/computercraft/client/gui/GuiPrinter.java

@@ -16,36 +16,30 @@ public class GuiPrinter extends GuiContainer
 {
     private static final ResourceLocation BACKGROUND = new ResourceLocation( "computercraft", "textures/gui/printer.png" );
 
-    private final ContainerPrinter m_container;
+    private final ContainerPrinter container;
 
     public GuiPrinter( ContainerPrinter container )
     {
         super( container );
-        m_container = container;
+        this.container = container;
     }
 
     @Override
-    protected void drawGuiContainerForegroundLayer( int par1, int par2 )
+    protected void drawGuiContainerForegroundLayer( int mouseX, int mouseY )
     {
-        String title = m_container.getPrinter().getDisplayName().getUnformattedText();
+        String title = container.getPrinter().getDisplayName().getUnformattedText();
         fontRenderer.drawString( title, (xSize - fontRenderer.getStringWidth( title )) / 2, 6, 0x404040 );
-        fontRenderer.drawString( I18n.format( "container.inventory" ), 8, (ySize - 96) + 2, 0x404040 );
+        fontRenderer.drawString( I18n.format( "container.inventory" ), 8, ySize - 96 + 2, 0x404040 );
     }
 
     @Override
-    protected void drawGuiContainerBackgroundLayer( float f, int i, int j )
+    protected void drawGuiContainerBackgroundLayer( float partialTicks, int mouseX, int mouseY )
     {
         GlStateManager.color( 1.0F, 1.0F, 1.0F, 1.0F );
-        this.mc.getTextureManager().bindTexture( BACKGROUND );
-        int startX = (width - xSize) / 2;
-        int startY = (height - ySize) / 2;
-        drawTexturedModalRect( startX, startY, 0, 0, xSize, ySize );
+        mc.getTextureManager().bindTexture( BACKGROUND );
+        drawTexturedModalRect( guiLeft, guiTop, 0, 0, xSize, ySize );
 
-        boolean printing = m_container.isPrinting();
-        if( printing )
-        {
-            drawTexturedModalRect( startX + 34, startY + 21, 176, 0, 25, 45 );
-        }
+        if( container.isPrinting() ) drawTexturedModalRect( guiLeft + 34, guiTop + 21, 176, 0, 25, 45 );
     }
 
     @Override

src/main/java/dan200/computercraft/client/gui/GuiPrintout.java

@@ -29,6 +29,8 @@ public class GuiPrintout extends GuiContainer
     {
         super( container );
 
+        ySize = Y_SIZE;
+
         String[] text = ItemPrintout.getText( container.getStack() );
         m_text = new TextBuffer[text.length];
         for( int i = 0; i < m_text.length; i++ ) m_text[i] = new TextBuffer( text[i] );
@@ -42,12 +44,6 @@ public class GuiPrintout extends GuiContainer
         m_book = ItemPrintout.getType( container.getStack() ) == ItemPrintout.Type.Book;
     }
 
-    @Override
-    public boolean doesGuiPauseGame()
-    {
-        return false;
-    }
-
     @Override
     protected void keyTyped( char c, int k ) throws IOException
     {
@@ -73,41 +69,35 @@ public class GuiPrintout extends GuiContainer
         int mouseWheelChange = Mouse.getEventDWheel();
         if( mouseWheelChange < 0 )
         {
-            // Up
+            // Scroll up goes to the next page
             if( m_page < m_pages - 1 ) m_page++;
         }
         else if( mouseWheelChange > 0 )
         {
-            // Down
+            // Scroll down goes to the previous page
             if( m_page > 0 ) m_page--;
         }
     }
 
     @Override
-    protected void drawGuiContainerForegroundLayer( int par1, int par2 )
+    protected void drawGuiContainerBackgroundLayer( float partialTicks, int mouseX, int mouseY )
     {
-    }
-
-    @Override
-    protected void drawGuiContainerBackgroundLayer( float var1, int var2, int var3 )
-    {
-    }
-
-    @Override
-    public void drawScreen( int mouseX, int mouseY, float f )
-    {
-        // Draw background
-        zLevel = zLevel - 1;
-        drawDefaultBackground();
-        zLevel = zLevel + 1;
-
         // Draw the printout
         GlStateManager.color( 1.0f, 1.0f, 1.0f, 1.0f );
 
-        int startY = (height - Y_SIZE) / 2;
-        int startX = (width - X_SIZE) / 2;
+        drawBorder( guiLeft, guiTop, zLevel, m_page, m_pages, m_book );
+        drawText( guiLeft + X_TEXT_MARGIN, guiTop + Y_TEXT_MARGIN, ItemPrintout.LINES_PER_PAGE * m_page, m_text, m_colours );
+    }
 
-        drawBorder( startX, startY, zLevel, m_page, m_pages, m_book );
-        drawText( startX + X_TEXT_MARGIN, startY + Y_TEXT_MARGIN, ItemPrintout.LINES_PER_PAGE * m_page, m_text, m_colours );
+    @Override
+    public void drawScreen( int mouseX, int mouseY, float partialTicks )
+    {
+        // We must take the background further back in order to not overlap with our printed pages.
+        zLevel--;
+        drawDefaultBackground();
+        zLevel++;
+
+        super.drawScreen( mouseX, mouseY, partialTicks );
+        renderHoveredToolTip( mouseX, mouseY );
     }
 }

src/main/java/dan200/computercraft/client/gui/GuiTurtle.java

@@ -23,7 +23,7 @@ import java.io.IOException;
 
 public class GuiTurtle extends GuiContainer
 {
-    private static final ResourceLocation BACKGROUND = new ResourceLocation( "computercraft", "textures/gui/turtle.png" );
+    private static final ResourceLocation BACKGROUND_NORMAL = new ResourceLocation( "computercraft", "textures/gui/turtle.png" );
     private static final ResourceLocation BACKGROUND_ADVANCED = new ResourceLocation( "computercraft", "textures/gui/turtle_advanced.png" );
 
     private ContainerTurtle m_container;
@@ -50,8 +50,8 @@ public class GuiTurtle extends GuiContainer
         super.initGui();
         Keyboard.enableRepeatEvents( true );
         m_terminalGui = new WidgetTerminal(
-            (width - xSize) / 2 + 8,
-            (height - ySize) / 2 + 8,
+            guiLeft + 8,
+            guiTop + 8,
             ComputerCraft.terminalWidth_turtle,
             ComputerCraft.terminalHeight_turtle,
             () -> m_computer,
@@ -98,8 +98,8 @@ public class GuiTurtle extends GuiContainer
     public void handleMouseInput() throws IOException
     {
         super.handleMouseInput();
-        int x = Mouse.getEventX() * this.width / mc.displayWidth;
-        int y = this.height - Mouse.getEventY() * this.height / mc.displayHeight - 1;
+        int x = Mouse.getEventX() * width / mc.displayWidth;
+        int y = height - Mouse.getEventY() * height / mc.displayHeight - 1;
         m_terminalGui.handleMouseInput( x, y );
     }
 
@@ -112,34 +112,29 @@ public class GuiTurtle extends GuiContainer
 
     protected void drawSelectionSlot( boolean advanced )
     {
-        int x = (width - xSize) / 2;
-        int y = (height - ySize) / 2;
-
         // Draw selection slot
         int slot = m_container.getSelectedSlot();
         if( slot >= 0 )
         {
             GlStateManager.color( 1.0F, 1.0F, 1.0F, 1.0F );
-            int slotX = (slot % 4);
-            int slotY = (slot / 4);
-            this.mc.getTextureManager().bindTexture( advanced ? BACKGROUND_ADVANCED : BACKGROUND );
-            drawTexturedModalRect( x + m_container.m_turtleInvStartX - 2 + slotX * 18, y + m_container.m_playerInvStartY - 2 + slotY * 18, 0, 217, 24, 24 );
+            int slotX = slot % 4;
+            int slotY = slot / 4;
+            mc.getTextureManager().bindTexture( advanced ? BACKGROUND_ADVANCED : BACKGROUND_NORMAL );
+            drawTexturedModalRect( guiLeft + m_container.turtleInvStartX - 2 + slotX * 18, guiTop + m_container.playerInvStartY - 2 + slotY * 18, 0, 217, 24, 24 );
         }
     }
 
     @Override
-    protected void drawGuiContainerBackgroundLayer( float f, int mouseX, int mouseY )
+    protected void drawGuiContainerBackgroundLayer( float partialTicks, int mouseX, int mouseY )
     {
         // Draw term
-        boolean advanced = (m_family == ComputerFamily.Advanced);
+        boolean advanced = m_family == ComputerFamily.Advanced;
         m_terminalGui.draw( Minecraft.getMinecraft(), 0, 0, mouseX, mouseY );
 
         // Draw border/inventory
         GlStateManager.color( 1.0F, 1.0F, 1.0F, 1.0F );
-        this.mc.getTextureManager().bindTexture( advanced ? BACKGROUND_ADVANCED : BACKGROUND );
-        int x = (width - xSize) / 2;
-        int y = (height - ySize) / 2;
-        drawTexturedModalRect( x, y, 0, 0, xSize, ySize );
+        mc.getTextureManager().bindTexture( advanced ? BACKGROUND_ADVANCED : BACKGROUND_NORMAL );
+        drawTexturedModalRect( guiLeft, guiTop, 0, 0, xSize, ySize );
 
         drawSelectionSlot( advanced );
     }

src/main/java/dan200/computercraft/client/gui/widgets/WidgetTerminal.java

@@ -31,23 +31,23 @@ public class WidgetTerminal extends Widget
 
     private final IComputerContainer m_computer;
 
-    private float m_terminateTimer;
-    private float m_rebootTimer;
-    private float m_shutdownTimer;
+    private float m_terminateTimer = 0.0f;
+    private float m_rebootTimer = 0.0f;
+    private float m_shutdownTimer = 0.0f;
 
-    private int m_lastClickButton;
-    private int m_lastClickX;
-    private int m_lastClickY;
+    private int m_lastClickButton = -1;
+    private int m_lastClickX = -1;
+    private int m_lastClickY = -1;
 
-    private boolean m_focus;
-    private boolean m_allowFocusLoss;
+    private boolean m_focus = false;
+    private boolean m_allowFocusLoss = true;
 
     private int m_leftMargin;
     private int m_rightMargin;
     private int m_topMargin;
     private int m_bottomMargin;
 
-    private ArrayList<Integer> m_keysDown;
+    private final ArrayList<Integer> m_keysDown = new ArrayList<>();
 
     public WidgetTerminal( int x, int y, int termWidth, int termHeight, IComputerContainer computer, int leftMargin, int rightMargin, int topMargin, int bottomMargin )
     {
@@ -58,23 +58,11 @@ public class WidgetTerminal extends Widget
         );
 
         m_computer = computer;
-        m_terminateTimer = 0.0f;
-        m_rebootTimer = 0.0f;
-        m_shutdownTimer = 0.0f;
-
-        m_lastClickButton = -1;
-        m_lastClickX = -1;
-        m_lastClickY = -1;
-
-        m_focus = false;
-        m_allowFocusLoss = true;
 
         m_leftMargin = leftMargin;
         m_rightMargin = rightMargin;
         m_topMargin = topMargin;
         m_bottomMargin = bottomMargin;
-
-        m_keysDown = new ArrayList<>();
     }
 
     public void setAllowFocusLoss( boolean allowFocusLoss )
@@ -94,9 +82,9 @@ public class WidgetTerminal extends Widget
                 String clipboard = GuiScreen.getClipboardString();
                 if( clipboard != null )
                 {
-                    // Clip to the first occurance of \r or \n
-                    int newLineIndex1 = clipboard.indexOf( "\r" );
-                    int newLineIndex2 = clipboard.indexOf( "\n" );
+                    // Clip to the first occurrence of \r or \n
+                    int newLineIndex1 = clipboard.indexOf( '\r' );
+                    int newLineIndex2 = clipboard.indexOf( '\n' );
                     if( newLineIndex1 >= 0 && newLineIndex2 >= 0 )
                     {
                         clipboard = clipboard.substring( 0, Math.min( newLineIndex1, newLineIndex2 ) );
@@ -122,9 +110,7 @@ public class WidgetTerminal extends Widget
                         }
 
                         // Queue the "paste" event
-                        queueEvent( "paste", new Object[] {
-                            clipboard
-                        } );
+                        queueEvent( "paste", new Object[] { clipboard } );
                     }
                 }
                 return true;
@@ -143,18 +129,15 @@ public class WidgetTerminal extends Widget
                     }
 
                     // Queue the "key" event
-                    queueEvent( "key", new Object[] {
-                        key, repeat
-                    } );
+                    IComputer computer = m_computer.getComputer();
+                    if( computer != null ) computer.keyDown( key, repeat );
                     handled = true;
                 }
 
                 if( (ch >= 32 && ch <= 126) || (ch >= 160 && ch <= 255) ) // printable chars in byte range
                 {
                     // Queue the "char" event
-                    queueEvent( "char", new Object[] {
-                        Character.toString( ch )
-                    } );
+                    queueEvent( "char", new Object[] { Character.toString( ch ) } );
                     handled = true;
                 }
 
@@ -189,9 +172,7 @@ public class WidgetTerminal extends Widget
                         charX = Math.min( Math.max( charX, 0 ), term.getWidth() - 1 );
                         charY = Math.min( Math.max( charY, 0 ), term.getHeight() - 1 );
 
-                        computer.queueEvent( "mouse_click", new Object[] {
-                            button + 1, charX + 1, charY + 1
-                        } );
+                        computer.mouseClick( button + 1, charX + 1, charY + 1 );
 
                         m_lastClickButton = button;
                         m_lastClickX = charX;
@@ -222,9 +203,8 @@ public class WidgetTerminal extends Widget
                 if( m_focus )
                 {
                     // Queue the "key_up" event
-                    queueEvent( "key_up", new Object[] {
-                        key
-                    } );
+                    IComputer computer = m_computer.getComputer();
+                    if( computer != null ) computer.keyUp( key );
                     handled = true;
                 }
             }
@@ -251,12 +231,7 @@ public class WidgetTerminal extends Widget
 
                 if( m_lastClickButton >= 0 && !Mouse.isButtonDown( m_lastClickButton ) )
                 {
-                    if( m_focus )
-                    {
-                        computer.queueEvent( "mouse_up", new Object[] {
-                            m_lastClickButton + 1, charX + 1, charY + 1
-                        } );
-                    }
+                    if( m_focus ) computer.mouseUp( m_lastClickButton + 1, charX + 1, charY + 1 );
                     m_lastClickButton = -1;
                 }
 
@@ -270,22 +245,16 @@ public class WidgetTerminal extends Widget
                 {
                     if( wheelChange < 0 )
                     {
-                        computer.queueEvent( "mouse_scroll", new Object[] {
-                            1, charX + 1, charY + 1
-                        } );
+                        computer.mouseScroll( 1, charX + 1, charY + 1 );
                     }
                     else if( wheelChange > 0 )
                     {
-                        computer.queueEvent( "mouse_scroll", new Object[] {
-                            -1, charX + 1, charY + 1
-                        } );
+                        computer.mouseScroll( -1, charX + 1, charY + 1 );
                     }
 
                     if( m_lastClickButton >= 0 && (charX != m_lastClickX || charY != m_lastClickY) )
                     {
-                        computer.queueEvent( "mouse_drag", new Object[] {
-                            m_lastClickButton + 1, charX + 1, charY + 1
-                        } );
+                        computer.mouseDrag( m_lastClickButton + 1, charX + 1, charY + 1 );
                         m_lastClickX = charX;
                         m_lastClickY = charY;
                     }
@@ -305,11 +274,8 @@ public class WidgetTerminal extends Widget
             {
                 if( m_terminateTimer < TERMINATE_TIME )
                 {
-                    m_terminateTimer = m_terminateTimer + 0.05f;
-                    if( m_terminateTimer >= TERMINATE_TIME )
-                    {
-                        queueEvent( "terminate" );
-                    }
+                    m_terminateTimer += 0.05f;
+                    if( m_terminateTimer >= TERMINATE_TIME ) queueEvent( "terminate" );
                 }
             }
             else
@@ -322,14 +288,11 @@ public class WidgetTerminal extends Widget
             {
                 if( m_rebootTimer < TERMINATE_TIME )
                 {
-                    m_rebootTimer = m_rebootTimer + 0.05f;
+                    m_rebootTimer += 0.05f;
                     if( m_rebootTimer >= TERMINATE_TIME )
                     {
                         IComputer computer = m_computer.getComputer();
-                        if( computer != null )
-                        {
-                            computer.reboot();
-                        }
+                        if( computer != null ) computer.reboot();
                     }
                 }
             }
@@ -343,14 +306,11 @@ public class WidgetTerminal extends Widget
             {
                 if( m_shutdownTimer < TERMINATE_TIME )
                 {
-                    m_shutdownTimer = m_shutdownTimer + 0.05f;
+                    m_shutdownTimer += 0.05f;
                     if( m_shutdownTimer >= TERMINATE_TIME )
                     {
                         IComputer computer = m_computer.getComputer();
-                        if( computer != null )
-                        {
-                            computer.shutdown();
-                        }
+                        if( computer != null ) computer.shutdown();
                     }
                 }
             }
@@ -377,7 +337,7 @@ public class WidgetTerminal extends Widget
         {
             // Draw the screen contents
             IComputer computer = m_computer.getComputer();
-            Terminal terminal = (computer != null) ? computer.getTerminal() : null;
+            Terminal terminal = computer != null ? computer.getTerminal() : null;
             if( terminal != null )
             {
                 // Draw the terminal
@@ -388,7 +348,7 @@ public class WidgetTerminal extends Widget
                 // Get the data from the terminal first
                 // Unfortunately we have to keep the lock for the whole of drawing, so the text doesn't change under us.
                 FixedWidthFontRenderer fontRenderer = FixedWidthFontRenderer.instance();
-                boolean tblink = m_focus && terminal.getCursorBlink() && FrameInfo.instance().getGlobalCursorBlink();
+                boolean tblink = m_focus && terminal.getCursorBlink() && FrameInfo.getGlobalCursorBlink();
                 int tw = terminal.getWidth();
                 int th = terminal.getHeight();
                 int tx = terminal.getCursorX();
@@ -455,18 +415,12 @@ public class WidgetTerminal extends Widget
     private void queueEvent( String event )
     {
         IComputer computer = m_computer.getComputer();
-        if( computer != null )
-        {
-            computer.queueEvent( event );
-        }
+        if( computer != null ) computer.queueEvent( event );
     }
 
     private void queueEvent( String event, Object[] args )
     {
         IComputer computer = m_computer.getComputer();
-        if( computer != null )
-        {
-            computer.queueEvent( event, args );
-        }
+        if( computer != null ) computer.queueEvent( event, args );
     }
 }

src/main/java/dan200/computercraft/client/proxy/CCTurtleProxyClient.java

@@ -1,214 +0,0 @@
-/*
- * This file is part of ComputerCraft - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2019. Do not distribute without permission.
- * Send enquiries to dratcliffe@gmail.com
- */
-
-package dan200.computercraft.client.proxy;
-
-import dan200.computercraft.ComputerCraft;
-import dan200.computercraft.client.render.TileEntityTurtleRenderer;
-import dan200.computercraft.client.render.TurtleSmartItemModel;
-import dan200.computercraft.shared.proxy.CCTurtleProxyCommon;
-import dan200.computercraft.shared.turtle.blocks.TileTurtle;
-import dan200.computercraft.shared.turtle.items.ItemTurtleBase;
-import net.minecraft.block.Block;
-import net.minecraft.client.Minecraft;
-import net.minecraft.client.renderer.ItemMeshDefinition;
-import net.minecraft.client.renderer.block.model.IBakedModel;
-import net.minecraft.client.renderer.block.model.ModelBakery;
-import net.minecraft.client.renderer.block.model.ModelResourceLocation;
-import net.minecraft.client.renderer.color.IItemColor;
-import net.minecraft.client.renderer.texture.TextureMap;
-import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
-import net.minecraft.client.resources.IResourceManager;
-import net.minecraft.client.resources.SimpleReloadableResourceManager;
-import net.minecraft.item.Item;
-import net.minecraft.item.ItemStack;
-import net.minecraft.util.ResourceLocation;
-import net.minecraftforge.client.event.ModelBakeEvent;
-import net.minecraftforge.client.event.ModelRegistryEvent;
-import net.minecraftforge.client.event.TextureStitchEvent;
-import net.minecraftforge.client.model.IModel;
-import net.minecraftforge.client.model.ModelLoader;
-import net.minecraftforge.client.model.ModelLoaderRegistry;
-import net.minecraftforge.common.MinecraftForge;
-import net.minecraftforge.fml.client.registry.ClientRegistry;
-import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
-
-import javax.annotation.Nonnull;
-
-public class CCTurtleProxyClient extends CCTurtleProxyCommon
-{
-    // IComputerCraftProxy implementation
-
-    @Override
-    public void preInit()
-    {
-        super.preInit();
-
-        // Setup client forge handlers
-        registerForgeHandlers();
-    }
-
-    @SubscribeEvent
-    public void registerModels( ModelRegistryEvent event )
-    {
-        // Register item models
-        ItemMeshDefinition turtleMeshDefinition = new ItemMeshDefinition()
-        {
-            private ModelResourceLocation turtle_dynamic = new ModelResourceLocation( "computercraft:turtle_dynamic", "inventory" );
-
-            @Nonnull
-            @Override
-            public ModelResourceLocation getModelLocation( @Nonnull ItemStack stack )
-            {
-                return turtle_dynamic;
-            }
-        };
-        String[] turtleModelNames = new String[] {
-            "turtle_dynamic",
-            "turtle", "turtle_advanced",
-            "turtle_white",
-            "turtle_elf_overlay"
-        };
-        registerItemModel( ComputerCraft.Blocks.turtle, turtleMeshDefinition, turtleModelNames );
-        registerItemModel( ComputerCraft.Blocks.turtleExpanded, turtleMeshDefinition, turtleModelNames );
-        registerItemModel( ComputerCraft.Blocks.turtleAdvanced, turtleMeshDefinition, turtleModelNames );
-    }
-
-    @Override
-    public void init()
-    {
-        super.init();
-
-        // Setup turtle colours
-        Minecraft.getMinecraft().getItemColors().registerItemColorHandler(
-            new TurtleItemColour(),
-            ComputerCraft.Blocks.turtle, ComputerCraft.Blocks.turtleExpanded, ComputerCraft.Blocks.turtleAdvanced
-        );
-
-        // Setup renderers
-        ClientRegistry.bindTileEntitySpecialRenderer( TileTurtle.class, new TileEntityTurtleRenderer() );
-    }
-
-    private void registerItemModel( Block block, ItemMeshDefinition definition, String[] names )
-    {
-        registerItemModel( Item.getItemFromBlock( block ), definition, names );
-    }
-
-    private void registerItemModel( Item item, ItemMeshDefinition definition, String[] names )
-    {
-        ResourceLocation[] resources = new ResourceLocation[names.length];
-        for( int i = 0; i < names.length; i++ )
-        {
-            resources[i] = new ResourceLocation( "computercraft:" + names[i] );
-        }
-        ModelBakery.registerItemVariants( item, resources );
-        ModelLoader.setCustomMeshDefinition( item, definition );
-    }
-
-    private void registerForgeHandlers()
-    {
-        ForgeHandlers handlers = new ForgeHandlers();
-        MinecraftForge.EVENT_BUS.register( handlers );
-    }
-
-    public static class ForgeHandlers
-    {
-        private static final String[] TURTLE_UPGRADES = {
-            "turtle_modem_off_left",
-            "turtle_modem_on_left",
-            "turtle_modem_off_right",
-            "turtle_modem_on_right",
-            "turtle_crafting_table_left",
-            "turtle_crafting_table_right",
-            "advanced_turtle_modem_off_left",
-            "advanced_turtle_modem_on_left",
-            "advanced_turtle_modem_off_right",
-            "advanced_turtle_modem_on_right",
-            "turtle_speaker_upgrade_left",
-            "turtle_speaker_upgrade_right",
-        };
-
-        private TurtleSmartItemModel m_turtleSmartItemModel;
-
-        public ForgeHandlers()
-        {
-            m_turtleSmartItemModel = new TurtleSmartItemModel();
-            IResourceManager resourceManager = Minecraft.getMinecraft().getResourceManager();
-            if( resourceManager instanceof SimpleReloadableResourceManager )
-            {
-                SimpleReloadableResourceManager reloadableResourceManager = (SimpleReloadableResourceManager) resourceManager;
-                reloadableResourceManager.registerReloadListener( m_turtleSmartItemModel );
-            }
-        }
-
-        @SubscribeEvent
-        public void onTextureStitchEvent( TextureStitchEvent.Pre event )
-        {
-            // Load all textures for upgrades
-            TextureMap map = event.getMap();
-            for( String upgrade : TURTLE_UPGRADES )
-            {
-                IModel model = ModelLoaderRegistry.getModelOrMissing( new ResourceLocation( "computercraft", "block/" + upgrade ) );
-                for( ResourceLocation texture : model.getTextures() )
-                {
-                    map.registerSprite( texture );
-                }
-            }
-        }
-
-        @SubscribeEvent
-        public void onModelBakeEvent( ModelBakeEvent event )
-        {
-            // Load all upgrade models
-            for( String upgrade : TURTLE_UPGRADES )
-            {
-                loadModel( event, upgrade );
-            }
-
-            loadSmartModel( event, "turtle_dynamic", m_turtleSmartItemModel );
-        }
-
-        private void loadModel( ModelBakeEvent event, String name )
-        {
-            IModel model = ModelLoaderRegistry.getModelOrMissing(
-                new ResourceLocation( "computercraft", "block/" + name )
-            );
-            IBakedModel bakedModel = model.bake(
-                model.getDefaultState(),
-                DefaultVertexFormats.ITEM,
-                location -> Minecraft.getMinecraft().getTextureMapBlocks().getAtlasSprite( location.toString() )
-            );
-            event.getModelRegistry().putObject(
-                new ModelResourceLocation( "computercraft:" + name, "inventory" ),
-                bakedModel
-            );
-        }
-
-        private void loadSmartModel( ModelBakeEvent event, String name, IBakedModel smartModel )
-        {
-            event.getModelRegistry().putObject(
-                new ModelResourceLocation( "computercraft:" + name, "inventory" ),
-                smartModel
-            );
-        }
-    }
-
-    private static class TurtleItemColour implements IItemColor
-    {
-        @Override
-        public int colorMultiplier( @Nonnull ItemStack stack, int tintIndex )
-        {
-            if( tintIndex == 0 )
-            {
-                ItemTurtleBase turtle = (ItemTurtleBase) stack.getItem();
-                int colour = turtle.getColour( stack );
-                if( colour != -1 ) return colour;
-            }
-
-            return 0xFFFFFF;
-        }
-    }
-}

src/main/java/dan200/computercraft/client/proxy/ComputerCraftProxyClient.java

@@ -7,41 +7,21 @@
 package dan200.computercraft.client.proxy;
 
 import dan200.computercraft.ComputerCraft;
-import dan200.computercraft.client.ClientTableFormatter;
-import dan200.computercraft.client.FrameInfo;
-import dan200.computercraft.client.render.*;
+import dan200.computercraft.client.render.TileEntityCableRenderer;
+import dan200.computercraft.client.render.TileEntityMonitorRenderer;
+import dan200.computercraft.client.render.TileEntityTurtleRenderer;
 import dan200.computercraft.shared.command.CommandCopy;
-import dan200.computercraft.shared.command.text.TableBuilder;
-import dan200.computercraft.shared.media.items.ItemDiskLegacy;
 import dan200.computercraft.shared.peripheral.modem.wired.TileCable;
 import dan200.computercraft.shared.peripheral.monitor.ClientMonitor;
 import dan200.computercraft.shared.peripheral.monitor.TileMonitor;
 import dan200.computercraft.shared.proxy.ComputerCraftProxyCommon;
-import dan200.computercraft.shared.util.Colour;
-import net.minecraft.block.Block;
-import net.minecraft.client.Minecraft;
-import net.minecraft.client.renderer.ItemMeshDefinition;
-import net.minecraft.client.renderer.block.model.ModelBakery;
-import net.minecraft.client.renderer.block.model.ModelResourceLocation;
-import net.minecraft.client.renderer.color.IItemColor;
-import net.minecraft.item.Item;
-import net.minecraft.item.ItemStack;
-import net.minecraft.util.ResourceLocation;
-import net.minecraft.util.SoundEvent;
-import net.minecraft.util.math.BlockPos;
-import net.minecraft.world.World;
+import dan200.computercraft.shared.turtle.blocks.TileTurtle;
 import net.minecraftforge.client.ClientCommandHandler;
-import net.minecraftforge.client.event.ModelRegistryEvent;
-import net.minecraftforge.client.model.ModelLoader;
-import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.event.world.WorldEvent;
 import net.minecraftforge.fml.client.registry.ClientRegistry;
+import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
 import net.minecraftforge.fml.relauncher.Side;
-import net.minecraftforge.fml.relauncher.SideOnly;
-
-import javax.annotation.Nonnull;
-import java.io.File;
 
 public class ComputerCraftProxyClient extends ComputerCraftProxyCommon
 {
@@ -50,143 +30,26 @@ public class ComputerCraftProxyClient extends ComputerCraftProxyCommon
     {
         super.preInit();
 
-        // Setup client forge handlers
-        registerForgeHandlers();
-
         // Register any client-specific commands
         ClientCommandHandler.instance.registerCommand( CommandCopy.INSTANCE );
     }
 
-    @SubscribeEvent
-    public void registerModels( ModelRegistryEvent event )
-    {
-        // Register item models
-        registerItemModel( ComputerCraft.Blocks.computer, "computer" );
-        registerItemModel( ComputerCraft.Blocks.peripheral, 0, "peripheral" );
-        registerItemModel( ComputerCraft.Blocks.peripheral, 1, "wireless_modem" );
-        registerItemModel( ComputerCraft.Blocks.peripheral, 2, "monitor" );
-        registerItemModel( ComputerCraft.Blocks.peripheral, 3, "printer" );
-        registerItemModel( ComputerCraft.Blocks.peripheral, 4, "advanced_monitor" );
-        registerItemModel( ComputerCraft.Blocks.cable, 0, "cable" );
-        registerItemModel( ComputerCraft.Blocks.cable, 1, "wired_modem" );
-        registerItemModel( ComputerCraft.Blocks.commandComputer, "command_computer" );
-        registerItemModel( ComputerCraft.Blocks.advancedModem, "advanced_modem" );
-        registerItemModel( ComputerCraft.Blocks.peripheral, 5, "speaker" );
-        registerItemModel( ComputerCraft.Blocks.wiredModemFull, "wired_modem_full" );
-
-        registerItemModel( ComputerCraft.Items.disk, "disk" );
-        registerItemModel( ComputerCraft.Items.diskExpanded, "disk_expanded" );
-        registerItemModel( ComputerCraft.Items.treasureDisk, "treasure_disk" );
-        registerItemModel( ComputerCraft.Items.printout, 0, "printout" );
-        registerItemModel( ComputerCraft.Items.printout, 1, "pages" );
-        registerItemModel( ComputerCraft.Items.printout, 2, "book" );
-        registerItemModel( ComputerCraft.Items.pocketComputer, "pocket_computer" );
-    }
-
     @Override
     public void init()
     {
         super.init();
 
-        // Load textures
-        Minecraft mc = Minecraft.getMinecraft();
-
-        // Setup
-        mc.getItemColors().registerItemColorHandler( new DiskColorHandler( ComputerCraft.Items.disk ), ComputerCraft.Items.disk );
-        mc.getItemColors().registerItemColorHandler( new DiskColorHandler( ComputerCraft.Items.diskExpanded ), ComputerCraft.Items.diskExpanded );
-
-        mc.getItemColors().registerItemColorHandler( ( stack, layer ) ->
-        {
-            switch( layer )
-            {
-                case 0:
-                default:
-                    return 0xFFFFFF;
-                case 1:
-                {
-                    // Frame colour
-                    int colour = ComputerCraft.Items.pocketComputer.getColour( stack );
-                    return colour == -1 ? 0xFFFFFF : colour;
-                }
-                case 2:
-                {
-                    // Light colour
-                    int colour = ComputerCraft.Items.pocketComputer.getLightState( stack );
-                    return colour == -1 ? Colour.Black.getHex() : colour;
-                }
-            }
-        }, ComputerCraft.Items.pocketComputer );
-
         // Setup renderers
         ClientRegistry.bindTileEntitySpecialRenderer( TileMonitor.class, new TileEntityMonitorRenderer() );
         ClientRegistry.bindTileEntitySpecialRenderer( TileCable.class, new TileEntityCableRenderer() );
+        ClientRegistry.bindTileEntitySpecialRenderer( TileTurtle.class, new TileEntityTurtleRenderer() );
     }
 
-    private void registerItemModel( Block block, int damage, String name )
-    {
-        registerItemModel( Item.getItemFromBlock( block ), damage, name );
-    }
-
-    private void registerItemModel( Item item, int damage, String name )
-    {
-        ModelResourceLocation res = new ModelResourceLocation( "computercraft:" + name, "inventory" );
-        ModelBakery.registerItemVariants( item, new ResourceLocation( "computercraft", name ) );
-        ModelLoader.setCustomModelResourceLocation( item, damage, res );
-    }
-
-    private void registerItemModel( Block block, String name )
-    {
-        registerItemModel( Item.getItemFromBlock( block ), name );
-    }
-
-    private void registerItemModel( Item item, String name )
-    {
-        final ModelResourceLocation res = new ModelResourceLocation( "computercraft:" + name, "inventory" );
-        ModelBakery.registerItemVariants( item, new ResourceLocation( "computercraft", name ) );
-        ModelLoader.setCustomMeshDefinition( item, new ItemMeshDefinition()
-        {
-            @Nonnull
-            @Override
-            public ModelResourceLocation getModelLocation( @Nonnull ItemStack stack )
-            {
-                return res;
-            }
-        } );
-    }
-
-    @Override
-    public File getWorldDir( World world )
-    {
-        return world.getSaveHandler().getWorldDirectory();
-    }
-
-    private void registerForgeHandlers()
-    {
-        MinecraftForge.EVENT_BUS.register( new ForgeHandlers() );
-        MinecraftForge.EVENT_BUS.register( new RenderOverlayCable() );
-        MinecraftForge.EVENT_BUS.register( new ItemPocketRenderer() );
-        MinecraftForge.EVENT_BUS.register( new ItemPrintoutRenderer() );
-        MinecraftForge.EVENT_BUS.register( FrameInfo.instance() );
-    }
-
-    @Override
-    public void playRecordClient( BlockPos pos, SoundEvent record, String info )
-    {
-        Minecraft mc = Minecraft.getMinecraft();
-        mc.world.playRecord( pos, record );
-        if( info != null ) mc.ingameGUI.setRecordPlayingMessage( info );
-    }
-
-    @Override
-    public void showTableClient( TableBuilder table )
-    {
-        ClientTableFormatter.INSTANCE.display( table );
-    }
-
-    public class ForgeHandlers
+    @Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Side.CLIENT )
+    public static final class ForgeHandlers
     {
         @SubscribeEvent
-        public void onWorldUnload( WorldEvent.Unload event )
+        public static void onWorldUnload( WorldEvent.Unload event )
         {
             if( event.getWorld().isRemote )
             {
@@ -195,20 +58,5 @@ public class ComputerCraftProxyClient extends ComputerCraftProxyCommon
         }
     }
 
-    @SideOnly( Side.CLIENT )
-    private static class DiskColorHandler implements IItemColor
-    {
-        private final ItemDiskLegacy disk;
 
-        private DiskColorHandler( ItemDiskLegacy disk )
-        {
-            this.disk = disk;
-        }
-
-        @Override
-        public int colorMultiplier( @Nonnull ItemStack stack, int layer )
-        {
-            return layer == 0 ? 0xFFFFFF : disk.getColour( stack );
-        }
-    }
 }

src/main/java/dan200/computercraft/client/render/CableHighlightRenderer.java

@@ -23,17 +23,24 @@ import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.RayTraceResult;
 import net.minecraft.world.World;
 import net.minecraftforge.client.event.DrawBlockHighlightEvent;
+import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
+import net.minecraftforge.fml.relauncher.Side;
 import org.lwjgl.opengl.GL11;
 
-public class RenderOverlayCable
+@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Side.CLIENT )
+public final class CableHighlightRenderer
 {
     private static final float EXPAND = 0.002f;
     private static final double MIN = CableBounds.MIN - EXPAND;
     private static final double MAX = CableBounds.MAX + EXPAND;
 
+    private CableHighlightRenderer()
+    {
+    }
+
     @SubscribeEvent
-    public void drawHighlight( DrawBlockHighlightEvent event )
+    public static void drawHighlight( DrawBlockHighlightEvent event )
     {
         if( event.getTarget().typeOfHit != RayTraceResult.Type.BLOCK ) return;
 
@@ -46,7 +53,7 @@ public class RenderOverlayCable
         state = state.getActualState( world, pos );
 
         event.setCanceled( true );
-        PeripheralType type = ComputerCraft.Blocks.cable.getPeripheralType( state );
+        PeripheralType type = BlockCable.getPeripheralType( state );
 
         GlStateManager.enableBlend();
         GlStateManager.tryBlendFuncSeparate( GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA, 1, 0 );

src/main/java/dan200/computercraft/client/render/ItemPocketRenderer.java

@@ -12,155 +12,242 @@ import dan200.computercraft.client.gui.FixedWidthFontRenderer;
 import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.core.terminal.TextBuffer;
 import dan200.computercraft.shared.computer.core.ClientComputer;
+import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.pocket.items.ItemPocketComputer;
+import dan200.computercraft.shared.util.Colour;
 import dan200.computercraft.shared.util.Palette;
 import net.minecraft.client.Minecraft;
+import net.minecraft.client.renderer.BufferBuilder;
 import net.minecraft.client.renderer.GlStateManager;
-import net.minecraft.client.renderer.RenderItem;
-import net.minecraft.client.renderer.block.model.IBakedModel;
-import net.minecraft.client.renderer.block.model.ItemCameraTransforms;
-import net.minecraft.client.renderer.texture.TextureManager;
-import net.minecraft.client.renderer.texture.TextureMap;
+import net.minecraft.client.renderer.Tessellator;
+import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
 import net.minecraft.item.ItemStack;
-import net.minecraftforge.client.ForgeHooksClient;
 import net.minecraftforge.client.event.RenderSpecificHandEvent;
+import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
 import net.minecraftforge.fml.relauncher.Side;
-import net.minecraftforge.fml.relauncher.SideOnly;
 import org.lwjgl.opengl.GL11;
 
-import static dan200.computercraft.client.gui.FixedWidthFontRenderer.FONT_HEIGHT;
-import static dan200.computercraft.client.gui.FixedWidthFontRenderer.FONT_WIDTH;
+import static dan200.computercraft.client.gui.FixedWidthFontRenderer.*;
+import static dan200.computercraft.client.gui.GuiComputer.*;
 
 /**
  * Emulates map rendering for pocket computers
  */
-@SideOnly( Side.CLIENT )
-public class ItemPocketRenderer extends ItemMapLikeRenderer
+@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Side.CLIENT )
+public final class ItemPocketRenderer extends ItemMapLikeRenderer
 {
+    private static final int MARGIN = 2;
+    private static final int FRAME = 12;
+    private static final int LIGHT_HEIGHT = 8;
+
+    private static final ItemPocketRenderer INSTANCE = new ItemPocketRenderer();
+
+    private ItemPocketRenderer()
+    {
+    }
+
     @SubscribeEvent
-    public void renderItem( RenderSpecificHandEvent event )
+    public static void renderItem( RenderSpecificHandEvent event )
     {
         ItemStack stack = event.getItemStack();
         if( !(stack.getItem() instanceof ItemPocketComputer) ) return;
 
         event.setCanceled( true );
-        renderItemFirstPerson( event.getHand(), event.getInterpolatedPitch(), event.getEquipProgress(), event.getSwingProgress(), event.getItemStack() );
+        INSTANCE.renderItemFirstPerson( event.getHand(), event.getInterpolatedPitch(), event.getEquipProgress(), event.getSwingProgress(), event.getItemStack() );
     }
 
     @Override
     protected void renderItem( ItemStack stack )
     {
-        // Setup various transformations. Note that these are partially adapated from the corresponding method
+        ClientComputer computer = ItemPocketComputer.createClientComputer( stack );
+        Terminal terminal = computer == null ? null : computer.getTerminal();
+
+        int termWidth, termHeight;
+        if( terminal == null )
+        {
+            termWidth = ComputerCraft.terminalWidth_pocketComputer;
+            termHeight = ComputerCraft.terminalHeight_pocketComputer;
+        }
+        else
+        {
+            termWidth = terminal.getWidth();
+            termHeight = terminal.getHeight();
+        }
+
+        int width = termWidth * FONT_WIDTH + MARGIN * 2;
+        int height = termHeight * FONT_HEIGHT + MARGIN * 2;
+
+        // Setup various transformations. Note that these are partially adapted from the corresponding method
         // in ItemRenderer
+        GlStateManager.pushMatrix();
+
         GlStateManager.disableLighting();
+        GlStateManager.disableDepth();
 
         GlStateManager.rotate( 180f, 0f, 1f, 0f );
         GlStateManager.rotate( 180f, 0f, 0f, 1f );
         GlStateManager.scale( 0.5, 0.5, 0.5 );
 
-        ItemPocketComputer pocketComputer = ComputerCraft.Items.pocketComputer;
-        ClientComputer computer = pocketComputer.createClientComputer( stack );
+        double scale = 0.75 / Math.max( width + FRAME * 2, height + FRAME * 2 + LIGHT_HEIGHT );
+        GlStateManager.scale( scale, scale, 0 );
+        GlStateManager.translate( -0.5 * width, -0.5 * height, 0 );
 
+        // Render the main frame
+        ComputerFamily family = ComputerCraft.Items.pocketComputer.getFamily( stack );
+        int frameColour = ComputerCraft.Items.pocketComputer.getColour( stack );
+        renderFrame( family, frameColour, width, height );
+
+        // Render the light
+        int lightColour = ItemPocketComputer.getLightState( stack );
+        if( lightColour == -1 ) lightColour = Colour.Black.getHex();
+        renderLight( lightColour, width, height );
+
+        if( computer != null && terminal != null )
         {
-            // First render the background item. We use the item's model rather than a direct texture as this ensures
-            // we display the pocket light and other such decorations.
-            GlStateManager.pushMatrix();
+            // If we've a computer and terminal then attempt to render it.
+            renderTerminal( terminal, !computer.isColour(), width, height );
+        }
+        else
+        {
+            // Otherwise render a plain background
+            Minecraft.getMinecraft().getTextureManager().bindTexture( BACKGROUND );
 
-            GlStateManager.scale( 1.0f, -1.0f, 1.0f );
+            Tessellator tessellator = Tessellator.getInstance();
+            BufferBuilder buffer = tessellator.getBuffer();
 
-            Minecraft minecraft = Minecraft.getMinecraft();
-            TextureManager textureManager = minecraft.getTextureManager();
-            RenderItem renderItem = minecraft.getRenderItem();
-
-            // Copy of RenderItem#renderItemModelIntoGUI but without the translation or scaling
-            textureManager.bindTexture( TextureMap.LOCATION_BLOCKS_TEXTURE );
-            textureManager.getTexture( TextureMap.LOCATION_BLOCKS_TEXTURE ).setBlurMipmap( false, false );
-
-            GlStateManager.enableRescaleNormal();
-            GlStateManager.enableAlpha();
-            GlStateManager.alphaFunc( GL11.GL_GREATER, 0.1F );
-            GlStateManager.enableBlend();
-            GlStateManager.blendFunc( GlStateManager.SourceFactor.SRC_ALPHA, GlStateManager.DestFactor.ONE_MINUS_SRC_ALPHA );
-            GlStateManager.color( 1.0F, 1.0F, 1.0F, 1.0F );
-
-            IBakedModel bakedmodel = renderItem.getItemModelWithOverrides( stack, null, null );
-            bakedmodel = ForgeHooksClient.handleCameraTransforms( bakedmodel, ItemCameraTransforms.TransformType.GUI, false );
-            renderItem.renderItem( stack, bakedmodel );
-
-            GlStateManager.disableAlpha();
-            GlStateManager.disableRescaleNormal();
-
-            GlStateManager.popMatrix();
+            Colour black = Colour.Black;
+            buffer.begin( GL11.GL_QUADS, DefaultVertexFormats.POSITION );
+            renderTexture( buffer, 0, 0, 0, 0, width, height, black.getR(), black.getG(), black.getB() );
+            tessellator.draw();
         }
 
-        // If we've a computer and terminal then attempt to render it.
-        if( computer != null )
+        GlStateManager.enableDepth();
+        GlStateManager.enableLighting();
+        GlStateManager.popMatrix();
+    }
+
+    private static void renderFrame( ComputerFamily family, int colour, int width, int height )
+    {
+
+        Minecraft.getMinecraft().getTextureManager().bindTexture( colour != -1
+            ? BACKGROUND_COLOUR
+            : family == ComputerFamily.Normal ? BACKGROUND_NORMAL : BACKGROUND_ADVANCED
+        );
+
+        float r = ((colour >>> 16) & 0xFF) / 255.0f;
+        float g = ((colour >>> 8) & 0xFF) / 255.0f;
+        float b = (colour & 0xFF) / 255.0f;
+
+        Tessellator tessellator = Tessellator.getInstance();
+        BufferBuilder buffer = tessellator.getBuffer();
+        buffer.begin( GL11.GL_QUADS, DefaultVertexFormats.POSITION_TEX_COLOR );
+
+        // Top left, middle, right
+        renderTexture( buffer, -FRAME, -FRAME, 12, 28, FRAME, FRAME, r, g, b );
+        renderTexture( buffer, 0, -FRAME, 0, 0, width, FRAME, r, g, b );
+        renderTexture( buffer, width, -FRAME, 24, 28, FRAME, FRAME, r, g, b );
+
+        // Left and bright border
+        renderTexture( buffer, -FRAME, 0, 0, 28, FRAME, height, r, g, b );
+        renderTexture( buffer, width, 0, 36, 28, FRAME, height, r, g, b );
+
+        // Bottom left, middle, right. We do this in three portions: the top inner corners, an extended region for
+        // lights, and then the bottom outer corners.
+        renderTexture( buffer, -FRAME, height, 12, 40, FRAME, FRAME / 2, r, g, b );
+        renderTexture( buffer, 0, height, 0, 12, width, FRAME / 2, r, g, b );
+        renderTexture( buffer, width, height, 24, 40, FRAME, FRAME / 2, r, g, b );
+
+        renderTexture( buffer, -FRAME, height + FRAME / 2, 12, 44, FRAME, LIGHT_HEIGHT, FRAME, 4, r, g, b );
+        renderTexture( buffer, 0, height + FRAME / 2, 0, 16, width, LIGHT_HEIGHT, FRAME, 4, r, g, b );
+        renderTexture( buffer, width, height + FRAME / 2, 24, 44, FRAME, LIGHT_HEIGHT, FRAME, 4, r, g, b );
+
+        renderTexture( buffer, -FRAME, height + LIGHT_HEIGHT + FRAME / 2, 12, 40 + FRAME / 2, FRAME, FRAME / 2, r, g, b );
+        renderTexture( buffer, 0, height + LIGHT_HEIGHT + FRAME / 2, 0, 12 + FRAME / 2, width, FRAME / 2, r, g, b );
+        renderTexture( buffer, width, height + LIGHT_HEIGHT + FRAME / 2, 24, 40 + FRAME / 2, FRAME, FRAME / 2, r, g, b );
+
+        tessellator.draw();
+    }
+
+    private static void renderLight( int colour, int width, int height )
+    {
+        GlStateManager.enableBlend();
+        GlStateManager.disableTexture2D();
+
+        float r = ((colour >>> 16) & 0xFF) / 255.0f;
+        float g = ((colour >>> 8) & 0xFF) / 255.0f;
+        float b = (colour & 0xFF) / 255.0f;
+
+        Tessellator tessellator = Tessellator.getInstance();
+        BufferBuilder buffer = tessellator.getBuffer();
+        buffer.begin( GL11.GL_QUADS, DefaultVertexFormats.POSITION_COLOR );
+        buffer.pos( width - LIGHT_HEIGHT * 2, height + LIGHT_HEIGHT + FRAME / 2.0f, 0.0D ).color( r, g, b, 1.0f ).endVertex();
+        buffer.pos( width, height + LIGHT_HEIGHT + FRAME / 2.0f, 0.0D ).color( r, g, b, 1.0f ).endVertex();
+        buffer.pos( width, height + FRAME / 2.0f, 0.0D ).color( r, g, b, 1.0f ).endVertex();
+        buffer.pos( width - LIGHT_HEIGHT * 2, height + FRAME / 2.0f, 0.0D ).color( r, g, b, 1.0f ).endVertex();
+
+        tessellator.draw();
+        GlStateManager.enableTexture2D();
+    }
+
+    private static void renderTerminal( Terminal terminal, boolean greyscale, int width, int height )
+    {
+        synchronized( terminal )
         {
-            Terminal terminal = computer.getTerminal();
-            if( terminal != null )
+            int termWidth = terminal.getWidth();
+            int termHeight = terminal.getHeight();
+
+            FixedWidthFontRenderer fontRenderer = FixedWidthFontRenderer.instance();
+            Palette palette = terminal.getPalette();
+
+            // Render top/bottom borders
+            TextBuffer emptyLine = new TextBuffer( ' ', termWidth );
+            fontRenderer.drawString(
+                emptyLine, MARGIN, 0,
+                terminal.getTextColourLine( 0 ), terminal.getBackgroundColourLine( 0 ), MARGIN, MARGIN, greyscale, palette
+            );
+            fontRenderer.drawString(
+                emptyLine, MARGIN, 2 * MARGIN + (termHeight - 1) * FixedWidthFontRenderer.FONT_HEIGHT,
+                terminal.getTextColourLine( termHeight - 1 ), terminal.getBackgroundColourLine( termHeight - 1 ), MARGIN, MARGIN, greyscale, palette
+            );
+
+            // Render the actual text
+            for( int line = 0; line < termWidth; line++ )
             {
-                synchronized( terminal )
-                {
-                    GlStateManager.pushMatrix();
-                    GlStateManager.disableDepth();
+                TextBuffer text = terminal.getLine( line );
+                TextBuffer colour = terminal.getTextColourLine( line );
+                TextBuffer backgroundColour = terminal.getBackgroundColourLine( line );
+                fontRenderer.drawString(
+                    text, MARGIN, MARGIN + line * FONT_HEIGHT,
+                    colour, backgroundColour, MARGIN, MARGIN, greyscale, palette
+                );
+            }
 
-                    // Reset the position to be at the top left corner of the pocket computer
-                    // Note we translate towards the screen slightly too.
-                    GlStateManager.translate( -8 / 16.0, -8 / 16.0, 0.5 / 16.0 );
-                    // Translate to the top left of the screen.
-                    GlStateManager.translate( 4 / 16.0, 3 / 16.0, 0 );
-
-                    // Work out the scaling required to resize the terminal in order to fit on the computer
-                    final int margin = 2;
-                    int tw = terminal.getWidth();
-                    int th = terminal.getHeight();
-                    int width = tw * FONT_WIDTH + margin * 2;
-                    int height = th * FONT_HEIGHT + margin * 2;
-                    int max = Math.max( height, width );
-
-                    // The grid is 8 * 8 wide, so we start with a base of 1/2 (8 / 16).
-                    double scale = 1.0 / 2.0 / max;
-                    GlStateManager.scale( scale, scale, scale );
-
-                    // The margin/start positions are determined in order for the terminal to be centred.
-                    int startX = (max - width) / 2 + margin;
-                    int startY = (max - height) / 2 + margin;
-
-                    FixedWidthFontRenderer fontRenderer = FixedWidthFontRenderer.instance();
-                    boolean greyscale = !computer.isColour();
-                    Palette palette = terminal.getPalette();
-
-                    // Render the actual text
-                    for( int line = 0; line < th; line++ )
-                    {
-                        TextBuffer text = terminal.getLine( line );
-                        TextBuffer colour = terminal.getTextColourLine( line );
-                        TextBuffer backgroundColour = terminal.getBackgroundColourLine( line );
-                        fontRenderer.drawString(
-                            text, startX, startY + line * FONT_HEIGHT,
-                            colour, backgroundColour, margin, margin, greyscale, palette
-                        );
-                    }
-
-                    // And render the cursor;
-                    int tx = terminal.getCursorX(), ty = terminal.getCursorY();
-                    if( terminal.getCursorBlink() && FrameInfo.instance().getGlobalCursorBlink() &&
-                        tx >= 0 && ty >= 0 && tx < tw && ty < th )
-                    {
-                        TextBuffer cursorColour = new TextBuffer( "0123456789abcdef".charAt( terminal.getTextColour() ), 1 );
-                        fontRenderer.drawString(
-                            new TextBuffer( '_', 1 ), startX + FONT_WIDTH * tx, startY + FONT_HEIGHT * ty,
-                            cursorColour, null, 0, 0, greyscale, palette
-                        );
-                    }
-
-                    GlStateManager.enableDepth();
-                    GlStateManager.popMatrix();
-                }
+            // And render the cursor;
+            int tx = terminal.getCursorX(), ty = terminal.getCursorY();
+            if( terminal.getCursorBlink() && FrameInfo.getGlobalCursorBlink() &&
+                tx >= 0 && ty >= 0 && tx < termWidth && ty < termHeight )
+            {
+                TextBuffer cursorColour = new TextBuffer( "0123456789abcdef".charAt( terminal.getTextColour() ), 1 );
+                fontRenderer.drawString(
+                    new TextBuffer( '_', 1 ), MARGIN + FONT_WIDTH * tx, MARGIN + FONT_HEIGHT * ty,
+                    cursorColour, null, 0, 0, greyscale, palette
+                );
             }
         }
+    }
 
-        GlStateManager.enableLighting();
+    private static void renderTexture( BufferBuilder builder, int x, int y, int textureX, int textureY, int width, int height, float r, float g, float b )
+    {
+        renderTexture( builder, x, y, textureX, textureY, width, height, width, height, r, g, b );
+    }
+
+    private static void renderTexture( BufferBuilder builder, int x, int y, int textureX, int textureY, int width, int height, int textureWidth, int textureHeight, float r, float g, float b )
+    {
+        float scale = 1 / 255.0f;
+        builder.pos( x, y + height, 0 ).tex( textureX * scale, (textureY + textureHeight) * scale ).color( r, g, b, 1.0f ).endVertex();
+        builder.pos( x + width, y + height, 0 ).tex( (textureX + textureWidth) * scale, (textureY + textureHeight) * scale ).color( r, g, b, 1.0f ).endVertex();
+        builder.pos( x + width, y, 0 ).tex( (textureX + textureWidth) * scale, textureY * scale ).color( r, g, b, 1.0f ).endVertex();
+        builder.pos( x, y, 0 ).tex( textureX * scale, textureY * scale ).color( r, g, b, 1.0f ).endVertex();
     }
 }

src/main/java/dan200/computercraft/client/render/ItemPrintoutRenderer.java

@@ -12,7 +12,9 @@ import net.minecraft.client.renderer.GlStateManager;
 import net.minecraft.item.ItemStack;
 import net.minecraftforge.client.event.RenderItemInFrameEvent;
 import net.minecraftforge.client.event.RenderSpecificHandEvent;
+import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
+import net.minecraftforge.fml.relauncher.Side;
 
 import static dan200.computercraft.client.gui.FixedWidthFontRenderer.FONT_HEIGHT;
 import static dan200.computercraft.client.gui.FixedWidthFontRenderer.FONT_WIDTH;
@@ -20,17 +22,27 @@ import static dan200.computercraft.client.render.PrintoutRenderer.*;
 import static dan200.computercraft.shared.media.items.ItemPrintout.LINES_PER_PAGE;
 import static dan200.computercraft.shared.media.items.ItemPrintout.LINE_MAX_LENGTH;
 
-public class ItemPrintoutRenderer extends ItemMapLikeRenderer
+/**
+ * Emulates map and item-frame rendering for printouts
+ */
+@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Side.CLIENT )
+public final class ItemPrintoutRenderer extends ItemMapLikeRenderer
 {
+    private static final ItemPrintoutRenderer INSTANCE = new ItemPrintoutRenderer();
+
+    private ItemPrintoutRenderer()
+    {
+    }
+
     @SubscribeEvent
-    public void onRenderInHand( RenderSpecificHandEvent event )
+    public static void onRenderInHand( RenderSpecificHandEvent event )
     {
         ItemStack stack = event.getItemStack();
         if( stack.getItem() != ComputerCraft.Items.printout ) return;
 
         event.setCanceled( true );
 
-        renderItemFirstPerson( event.getHand(), event.getInterpolatedPitch(), event.getEquipProgress(), event.getSwingProgress(), event.getItemStack() );
+        INSTANCE.renderItemFirstPerson( event.getHand(), event.getInterpolatedPitch(), event.getEquipProgress(), event.getSwingProgress(), event.getItemStack() );
     }
 
     @Override
@@ -51,7 +63,7 @@ public class ItemPrintoutRenderer extends ItemMapLikeRenderer
     }
 
     @SubscribeEvent
-    public void onRenderInFrame( RenderItemInFrameEvent event )
+    public static void onRenderInFrame( RenderItemInFrameEvent event )
     {
         ItemStack stack = event.getItem();
         if( stack.getItem() != ComputerCraft.Items.printout ) return;
@@ -69,6 +81,7 @@ public class ItemPrintoutRenderer extends ItemMapLikeRenderer
         drawPrintout( stack );
 
         GlStateManager.enableLighting();
+        GlStateManager.disableBlend();
     }
 
     private static void drawPrintout( ItemStack stack )

src/main/java/dan200/computercraft/client/render/ModelTransformer.java

@@ -94,7 +94,7 @@ public final class ModelTransformer
         private final Point3f[] before = new Point3f[4];
         private final Point3f[] after = new Point3f[4];
 
-        public NormalAwareTransformer( IVertexConsumer parent, Matrix4f positionMatrix, Matrix4f normalMatrix )
+        NormalAwareTransformer( IVertexConsumer parent, Matrix4f positionMatrix, Matrix4f normalMatrix )
         {
             super( parent );
             this.positionMatrix = positionMatrix;
@@ -180,7 +180,7 @@ public final class ModelTransformer
      *
      * This also provides the ability to swap vertices through {@link #swap(int, int)} to allow reordering.
      */
-    private static class BakedQuadBuilder implements IVertexConsumer
+    private static final class BakedQuadBuilder implements IVertexConsumer
     {
         private final VertexFormat format;
 
@@ -195,7 +195,7 @@ public final class ModelTransformer
         private BakedQuadBuilder( VertexFormat format )
         {
             this.format = format;
-            this.vertexData = new int[format.getSize()];
+            vertexData = new int[format.getSize()];
         }
 
         @Nonnull
@@ -208,7 +208,7 @@ public final class ModelTransformer
         @Override
         public void setQuadTint( int tint )
         {
-            this.quadTint = tint;
+            quadTint = tint;
         }
 
         @Override

src/main/java/dan200/computercraft/client/render/MonitorHighlightRenderer.java

@@ -0,0 +1,118 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2019. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.client.render;
+
+import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.shared.peripheral.monitor.TileMonitor;
+import net.minecraft.client.renderer.BufferBuilder;
+import net.minecraft.client.renderer.GlStateManager;
+import net.minecraft.client.renderer.Tessellator;
+import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
+import net.minecraft.entity.player.EntityPlayer;
+import net.minecraft.tileentity.TileEntity;
+import net.minecraft.util.EnumFacing;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.RayTraceResult;
+import net.minecraft.world.World;
+import net.minecraftforge.client.event.DrawBlockHighlightEvent;
+import net.minecraftforge.fml.common.Mod;
+import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
+import net.minecraftforge.fml.relauncher.Side;
+import org.lwjgl.opengl.GL11;
+
+import java.util.EnumSet;
+
+import static net.minecraft.util.EnumFacing.*;
+
+@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Side.CLIENT )
+public final class MonitorHighlightRenderer
+{
+    private static final float EXPAND = 0.002f;
+
+    private MonitorHighlightRenderer()
+    {
+    }
+
+    @SubscribeEvent
+    public static void drawHighlight( DrawBlockHighlightEvent event )
+    {
+        if( event.getTarget().typeOfHit != RayTraceResult.Type.BLOCK || event.getPlayer().isSneaking() ) return;
+
+        World world = event.getPlayer().getEntityWorld();
+        BlockPos pos = event.getTarget().getBlockPos();
+
+        if( world.getBlockState( pos ).getBlock() != ComputerCraft.Blocks.peripheral ) return;
+
+        TileEntity tile = world.getTileEntity( pos );
+        if( !(tile instanceof TileMonitor) ) return;
+
+        TileMonitor monitor = (TileMonitor) tile;
+        event.setCanceled( true );
+
+        // Determine which sides are part of the external faces of the monitor, and so which need to be rendered.
+        EnumSet<EnumFacing> faces = EnumSet.allOf( EnumFacing.class );
+        EnumFacing front = monitor.getFront();
+        faces.remove( front );
+        if( monitor.getXIndex() != 0 ) faces.remove( monitor.getRight().getOpposite() );
+        if( monitor.getXIndex() != monitor.getWidth() - 1 ) faces.remove( monitor.getRight() );
+        if( monitor.getYIndex() != 0 ) faces.remove( monitor.getDown().getOpposite() );
+        if( monitor.getYIndex() != monitor.getHeight() - 1 ) faces.remove( monitor.getDown() );
+
+        GlStateManager.enableBlend();
+        GlStateManager.tryBlendFuncSeparate( GlStateManager.SourceFactor.SRC_ALPHA, GlStateManager.DestFactor.ONE_MINUS_SRC_ALPHA, GlStateManager.SourceFactor.ONE, GlStateManager.DestFactor.ZERO );
+        GL11.glLineWidth( 2.0F );
+        GlStateManager.disableTexture2D();
+        GlStateManager.depthMask( false );
+        GlStateManager.pushMatrix();
+
+        EntityPlayer player = event.getPlayer();
+        double x = player.lastTickPosX + (player.posX - player.lastTickPosX) * event.getPartialTicks();
+        double y = player.lastTickPosY + (player.posY - player.lastTickPosY) * event.getPartialTicks();
+        double z = player.lastTickPosZ + (player.posZ - player.lastTickPosZ) * event.getPartialTicks();
+
+        GlStateManager.translate( -x + pos.getX(), -y + pos.getY(), -z + pos.getZ() );
+
+        Tessellator tessellator = Tessellator.getInstance();
+        BufferBuilder buffer = tessellator.getBuffer();
+        buffer.begin( GL11.GL_LINES, DefaultVertexFormats.POSITION_COLOR );
+
+        // I wish I could think of a better way to do this
+        if( faces.contains( NORTH ) || faces.contains( WEST ) ) line( buffer, 0, 0, 0, UP );
+        if( faces.contains( SOUTH ) || faces.contains( WEST ) ) line( buffer, 0, 0, 1, UP );
+        if( faces.contains( NORTH ) || faces.contains( EAST ) ) line( buffer, 1, 0, 0, UP );
+        if( faces.contains( SOUTH ) || faces.contains( EAST ) ) line( buffer, 1, 0, 1, UP );
+        if( faces.contains( NORTH ) || faces.contains( DOWN ) ) line( buffer, 0, 0, 0, EAST );
+        if( faces.contains( SOUTH ) || faces.contains( DOWN ) ) line( buffer, 0, 0, 1, EAST );
+        if( faces.contains( NORTH ) || faces.contains( UP ) ) line( buffer, 0, 1, 0, EAST );
+        if( faces.contains( SOUTH ) || faces.contains( UP ) ) line( buffer, 0, 1, 1, EAST );
+        if( faces.contains( WEST ) || faces.contains( DOWN ) ) line( buffer, 0, 0, 0, SOUTH );
+        if( faces.contains( EAST ) || faces.contains( DOWN ) ) line( buffer, 1, 0, 0, SOUTH );
+        if( faces.contains( WEST ) || faces.contains( UP ) ) line( buffer, 0, 1, 0, SOUTH );
+        if( faces.contains( EAST ) || faces.contains( UP ) ) line( buffer, 1, 1, 0, SOUTH );
+
+        tessellator.draw();
+
+        GlStateManager.popMatrix();
+        GlStateManager.depthMask( true );
+        GlStateManager.enableTexture2D();
+        GlStateManager.disableBlend();
+    }
+
+    private static void line( BufferBuilder buffer, int x, int y, int z, EnumFacing direction )
+    {
+        double minX = x == 0 ? -EXPAND : 1 + EXPAND;
+        double minY = y == 0 ? -EXPAND : 1 + EXPAND;
+        double minZ = z == 0 ? -EXPAND : 1 + EXPAND;
+
+        buffer.pos( minX, minY, minZ ).color( 0, 0, 0, 0.4f ).endVertex();
+        buffer.pos(
+            minX + direction.getXOffset() * (1 + EXPAND * 2),
+            minY + direction.getYOffset() * (1 + EXPAND * 2),
+            minZ + direction.getZOffset() * (1 + EXPAND * 2)
+        ).color( 0, 0, 0, 0.4f ).endVertex();
+    }
+}

src/main/java/dan200/computercraft/client/render/PrintoutRenderer.java

@@ -12,6 +12,8 @@ import dan200.computercraft.shared.util.Palette;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.BufferBuilder;
 import net.minecraft.client.renderer.GlStateManager;
+import net.minecraft.client.renderer.GlStateManager.DestFactor;
+import net.minecraft.client.renderer.GlStateManager.SourceFactor;
 import net.minecraft.client.renderer.Tessellator;
 import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
 import net.minecraft.util.ResourceLocation;
@@ -20,7 +22,7 @@ import org.lwjgl.opengl.GL11;
 import static dan200.computercraft.client.gui.FixedWidthFontRenderer.FONT_HEIGHT;
 import static dan200.computercraft.shared.media.items.ItemPrintout.LINES_PER_PAGE;
 
-public class PrintoutRenderer
+public final class PrintoutRenderer
 {
     private static final ResourceLocation BG = new ResourceLocation( "computercraft", "textures/gui/printout.png" );
     private static final double BG_SIZE = 256.0;
@@ -58,6 +60,8 @@ public class PrintoutRenderer
     private static final int COVER_Y = Y_SIZE;
     private static final int COVER_X = X_SIZE + 4 * X_FOLD_SIZE;
 
+    private PrintoutRenderer() {}
+
     public static void drawText( int x, int y, int start, TextBuffer[] text, TextBuffer[] colours )
     {
         FixedWidthFontRenderer fontRenderer = FixedWidthFontRenderer.instance();
@@ -73,6 +77,7 @@ public class PrintoutRenderer
         GlStateManager.color( 1.0f, 1.0f, 1.0f, 1.0f );
         GlStateManager.enableBlend();
         GlStateManager.enableTexture2D();
+        GlStateManager.tryBlendFuncSeparate( SourceFactor.SRC_ALPHA, DestFactor.ONE_MINUS_SRC_ALPHA, SourceFactor.ONE, DestFactor.ZERO );
 
         FixedWidthFontRenderer fontRenderer = FixedWidthFontRenderer.instance();
 
@@ -87,6 +92,7 @@ public class PrintoutRenderer
         GlStateManager.color( 1.0f, 1.0f, 1.0f, 1.0f );
         GlStateManager.enableBlend();
         GlStateManager.enableTexture2D();
+        GlStateManager.tryBlendFuncSeparate( SourceFactor.SRC_ALPHA, DestFactor.ONE_MINUS_SRC_ALPHA, SourceFactor.ONE, DestFactor.ZERO );
 
         Minecraft.getMinecraft().getTextureManager().bindTexture( BG );
 

src/main/java/dan200/computercraft/client/render/TileEntityCableRenderer.java

@@ -61,11 +61,11 @@ public class TileEntityCableRenderer extends TileEntitySpecialRenderer<TileCable
         state = state.getActualState( world, pos );
         if( te.getPeripheralType() != PeripheralType.Cable && WorldUtil.isVecInsideInclusive( CableBounds.getModemBounds( state ), hit.hitVec.subtract( pos.getX(), pos.getY(), pos.getZ() ) ) )
         {
-            state = block.getDefaultState().withProperty( BlockCable.Properties.MODEM, state.getValue( BlockCable.Properties.MODEM ) );
+            state = block.getDefaultState().withProperty( BlockCable.MODEM, state.getValue( BlockCable.MODEM ) );
         }
         else
         {
-            state = state.withProperty( BlockCable.Properties.MODEM, BlockCableModemVariant.None );
+            state = state.withProperty( BlockCable.MODEM, BlockCableModemVariant.None );
         }
 
         IBakedModel model = mc.getBlockRendererDispatcher().getModelForState( state );

src/main/java/dan200/computercraft/client/render/TileEntityMonitorRenderer.java

@@ -37,7 +37,7 @@ public class TileEntityMonitorRenderer extends TileEntitySpecialRenderer<TileMon
         }
     }
 
-    private void renderMonitorAt( TileMonitor monitor, double posX, double posY, double posZ, float f, int i )
+    private static void renderMonitorAt( TileMonitor monitor, double posX, double posY, double posZ, float f, int i )
     {
         // Render from the origin monitor
         ClientMonitor originTerminal = monitor.getClientMonitor();
@@ -49,7 +49,7 @@ public class TileEntityMonitorRenderer extends TileEntitySpecialRenderer<TileMon
         // Ensure each monitor terminal is rendered only once. We allow rendering a specific tile
         // multiple times in a single frame to ensure compatibility with shaders which may run a
         // pass multiple times.
-        long renderFrame = FrameInfo.instance().getRenderFrame();
+        long renderFrame = FrameInfo.getRenderFrame();
         if( originTerminal.lastRenderFrame == renderFrame && !monitorPos.equals( originTerminal.lastRenderPos ) )
         {
             return;
@@ -78,7 +78,7 @@ public class TileEntityMonitorRenderer extends TileEntitySpecialRenderer<TileMon
             GlStateManager.rotate( pitch, 1.0f, 0.0f, 0.0f );
             GlStateManager.translate(
                 -0.5 + TileMonitor.RENDER_BORDER + TileMonitor.RENDER_MARGIN,
-                (origin.getHeight() - 0.5) - (TileMonitor.RENDER_BORDER + TileMonitor.RENDER_MARGIN),
+                origin.getHeight() - 0.5 - (TileMonitor.RENDER_BORDER + TileMonitor.RENDER_MARGIN),
                 0.5
             );
             double xSize = origin.getWidth() - 2.0 * (TileMonitor.RENDER_MARGIN + TileMonitor.RENDER_BORDER);
@@ -230,7 +230,7 @@ public class TileEntityMonitorRenderer extends TileEntitySpecialRenderer<TileMon
                                 GlStateManager.glEndList();
                             }
                         }
-                        if( FrameInfo.instance().getGlobalCursorBlink() )
+                        if( FrameInfo.getGlobalCursorBlink() )
                         {
                             GlStateManager.callList( originTerminal.renderDisplayLists[2] );
                             GlStateManager.resetColor();

src/main/java/dan200/computercraft/client/render/TileEntityTurtleRenderer.java

@@ -14,23 +14,20 @@ import dan200.computercraft.shared.util.Holiday;
 import dan200.computercraft.shared.util.HolidayUtil;
 import net.minecraft.block.state.IBlockState;
 import net.minecraft.client.Minecraft;
-import net.minecraft.client.gui.FontRenderer;
 import net.minecraft.client.renderer.BufferBuilder;
+import net.minecraft.client.renderer.EntityRenderer;
 import net.minecraft.client.renderer.GlStateManager;
 import net.minecraft.client.renderer.Tessellator;
 import net.minecraft.client.renderer.block.model.BakedQuad;
 import net.minecraft.client.renderer.block.model.IBakedModel;
 import net.minecraft.client.renderer.block.model.ModelManager;
 import net.minecraft.client.renderer.block.model.ModelResourceLocation;
-import net.minecraft.client.renderer.entity.RenderManager;
 import net.minecraft.client.renderer.texture.TextureMap;
 import net.minecraft.client.renderer.tileentity.TileEntitySpecialRenderer;
 import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
 import net.minecraft.client.renderer.vertex.VertexFormat;
 import net.minecraft.util.EnumFacing;
 import net.minecraft.util.ResourceLocation;
-import net.minecraft.util.math.BlockPos;
-import net.minecraft.util.math.RayTraceResult;
 import net.minecraft.util.math.Vec3d;
 import net.minecraftforge.client.ForgeHooksClient;
 import net.minecraftforge.client.model.pipeline.LightUtil;
@@ -48,9 +45,9 @@ public class TileEntityTurtleRenderer extends TileEntitySpecialRenderer<TileTurt
     private static final ModelResourceLocation ELF_OVERLAY_MODEL = new ModelResourceLocation( "computercraft:turtle_elf_overlay", "inventory" );
 
     @Override
-    public void render( TileTurtle tileEntity, double posX, double posY, double posZ, float f, int i, float f2 )
+    public void render( TileTurtle tileEntity, double posX, double posY, double posZ, float partialTicks, int breaking, float f2 )
     {
-        if( tileEntity != null ) renderTurtleAt( tileEntity, posX, posY, posZ, f, i );
+        if( tileEntity != null ) renderTurtleAt( tileEntity, posX, posY, posZ, partialTicks );
     }
 
     public static ModelResourceLocation getTurtleModel( ComputerFamily family, boolean coloured )
@@ -65,7 +62,7 @@ public class TileEntityTurtleRenderer extends TileEntitySpecialRenderer<TileTurt
         }
     }
 
-    public static ModelResourceLocation getTurtleOverlayModel( ComputerFamily family, ResourceLocation overlay, boolean christmas )
+    public static ModelResourceLocation getTurtleOverlayModel( ResourceLocation overlay, boolean christmas )
     {
         if( overlay != null )
         {
@@ -81,26 +78,30 @@ public class TileEntityTurtleRenderer extends TileEntitySpecialRenderer<TileTurt
         }
     }
 
-    private void renderTurtleAt( TileTurtle turtle, double posX, double posY, double posZ, float f, int i )
+    private void renderTurtleAt( TileTurtle turtle, double posX, double posY, double posZ, float partialTicks )
     {
-        IBlockState state = turtle.getWorld().getBlockState( turtle.getPos() );
+        // Render the label
+        String label = turtle.createProxy().getLabel();
+        if( label != null && rendererDispatcher.cameraHitResult != null && turtle.getPos().equals( rendererDispatcher.cameraHitResult.getBlockPos() ) )
+        {
+            setLightmapDisabled( true );
+            EntityRenderer.drawNameplate(
+                getFontRenderer(), label,
+                (float) posX + 0.5F, (float) posY + 1.2F, (float) posZ + 0.5F, 0,
+                rendererDispatcher.entityYaw, rendererDispatcher.entityPitch, false, false
+            );
+            setLightmapDisabled( false );
+        }
+
         GlStateManager.pushMatrix();
         try
         {
+            IBlockState state = turtle.getWorld().getBlockState( turtle.getPos() );
             // Setup the transform
-            Vec3d offset;
-            float yaw;
-            offset = turtle.getRenderOffset( f );
-            yaw = turtle.getRenderYaw( f );
+            Vec3d offset = turtle.getRenderOffset( partialTicks );
+            float yaw = turtle.getRenderYaw( partialTicks );
             GlStateManager.translate( posX + offset.x, posY + offset.y, posZ + offset.z );
 
-            // Render the label
-            String label = turtle.createProxy().getLabel();
-            if( label != null )
-            {
-                renderLabel( turtle.getAccess().getPosition(), label );
-            }
-
             // Render the turtle
             GlStateManager.translate( 0.5f, 0.5f, 0.5f );
             GlStateManager.rotate( 180.0f - yaw, 0.0f, 1.0f, 0.0f );
@@ -112,18 +113,14 @@ public class TileEntityTurtleRenderer extends TileEntitySpecialRenderer<TileTurt
             }
             GlStateManager.translate( -0.5f, -0.5f, -0.5f );
             // Render the turtle
-            int colour;
-            ComputerFamily family;
-            ResourceLocation overlay;
-            colour = turtle.getColour();
-            family = turtle.getFamily();
-            overlay = turtle.getOverlay();
+            int colour = turtle.getColour();
+            ComputerFamily family = turtle.getFamily();
+            ResourceLocation overlay = turtle.getOverlay();
 
             renderModel( state, getTurtleModel( family, colour != -1 ), colour == -1 ? null : new int[] { colour } );
 
             // Render the overlay
             ModelResourceLocation overlayModel = getTurtleOverlayModel(
-                family,
                 overlay,
                 HolidayUtil.getCurrentHoliday() == Holiday.Christmas
             );
@@ -144,8 +141,8 @@ public class TileEntityTurtleRenderer extends TileEntitySpecialRenderer<TileTurt
             }
 
             // Render the upgrades
-            renderUpgrade( state, turtle, TurtleSide.Left, f );
-            renderUpgrade( state, turtle, TurtleSide.Right, f );
+            renderUpgrade( state, turtle, TurtleSide.Left, partialTicks );
+            renderUpgrade( state, turtle, TurtleSide.Right, partialTicks );
         }
         finally
         {
@@ -154,7 +151,7 @@ public class TileEntityTurtleRenderer extends TileEntitySpecialRenderer<TileTurt
         }
     }
 
-    private void renderUpgrade( IBlockState state, TileTurtle turtle, TurtleSide side, float f )
+    private static void renderUpgrade( IBlockState state, TileTurtle turtle, TurtleSide side, float f )
     {
         ITurtleUpgrade upgrade = turtle.getUpgrade( side );
         if( upgrade != null )
@@ -187,14 +184,14 @@ public class TileEntityTurtleRenderer extends TileEntitySpecialRenderer<TileTurt
         }
     }
 
-    private void renderModel( IBlockState state, ModelResourceLocation modelLocation, int[] tints )
+    private static void renderModel( IBlockState state, ModelResourceLocation modelLocation, int[] tints )
     {
         Minecraft mc = Minecraft.getMinecraft();
         ModelManager modelManager = mc.getRenderItem().getItemModelMesher().getModelManager();
         renderModel( state, modelManager.getModel( modelLocation ), tints );
     }
 
-    private void renderModel( IBlockState state, IBakedModel model, int[] tints )
+    private static void renderModel( IBlockState state, IBakedModel model, int[] tints )
     {
         Minecraft mc = Minecraft.getMinecraft();
         Tessellator tessellator = Tessellator.getInstance();
@@ -206,7 +203,7 @@ public class TileEntityTurtleRenderer extends TileEntitySpecialRenderer<TileTurt
         }
     }
 
-    private void renderQuads( Tessellator tessellator, List<BakedQuad> quads, int[] tints )
+    private static void renderQuads( Tessellator tessellator, List<BakedQuad> quads, int[] tints )
     {
         BufferBuilder buffer = tessellator.getBuffer();
         VertexFormat format = DefaultVertexFormats.ITEM;
@@ -232,72 +229,4 @@ public class TileEntityTurtleRenderer extends TileEntitySpecialRenderer<TileTurt
         }
         tessellator.draw();
     }
-
-    private void renderLabel( BlockPos position, String label )
-    {
-        Minecraft mc = Minecraft.getMinecraft();
-        RayTraceResult mop = mc.objectMouseOver;
-        if( mop != null && mop.typeOfHit == RayTraceResult.Type.BLOCK && mop.getBlockPos().equals( position ) )
-        {
-            RenderManager renderManager = mc.getRenderManager();
-            FontRenderer fontrenderer = renderManager.getFontRenderer();
-            float scale = 0.016666668F * 1.6f;
-
-            GlStateManager.pushMatrix();
-            GlStateManager.disableLighting();
-            GlStateManager.enableBlend();
-            GlStateManager.blendFunc( GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA );
-            try
-            {
-                GlStateManager.translate( 0.5f, 1.25f, 0.5f );
-                GlStateManager.rotate( -renderManager.playerViewY, 0.0F, 1.0F, 0.0F );
-                GlStateManager.rotate( renderManager.playerViewX, 1.0F, 0.0F, 0.0F );
-                GlStateManager.scale( -scale, -scale, scale );
-
-                int yOffset = 0;
-                int xOffset = fontrenderer.getStringWidth( label ) / 2;
-
-                // Draw background
-                GlStateManager.depthMask( false );
-                GlStateManager.disableDepth();
-                try
-                {
-                    // Quad
-                    GlStateManager.disableTexture2D();
-                    try
-                    {
-                        Tessellator tessellator = Tessellator.getInstance();
-                        BufferBuilder renderer = tessellator.getBuffer();
-                        renderer.begin( GL11.GL_QUADS, DefaultVertexFormats.POSITION_COLOR );
-                        renderer.pos( -xOffset - 1, -1 + yOffset, 0.0D ).color( 0.0F, 0.0F, 0.0F, 0.25F ).endVertex();
-                        renderer.pos( -xOffset - 1, 8 + yOffset, 0.0D ).color( 0.0F, 0.0F, 0.0F, 0.25F ).endVertex();
-                        renderer.pos( xOffset + 1, 8 + yOffset, 0.0D ).color( 0.0F, 0.0F, 0.0F, 0.25F ).endVertex();
-                        renderer.pos( xOffset + 1, -1 + yOffset, 0.0D ).color( 0.0F, 0.0F, 0.0F, 0.25F ).endVertex();
-                        tessellator.draw();
-                    }
-                    finally
-                    {
-                        GlStateManager.enableTexture2D();
-                    }
-
-                    // Text
-                    fontrenderer.drawString( label, -fontrenderer.getStringWidth( label ) / 2, yOffset, 0x20ffffff );
-                }
-                finally
-                {
-                    GlStateManager.enableDepth();
-                    GlStateManager.depthMask( true );
-                }
-
-                // Draw foreground text
-                fontrenderer.drawString( label, -fontrenderer.getStringWidth( label ) / 2, yOffset, -1 );
-            }
-            finally
-            {
-                GlStateManager.disableBlend();
-                GlStateManager.enableLighting();
-                GlStateManager.popMatrix();
-            }
-        }
-    }
 }

src/main/java/dan200/computercraft/client/render/TurtleModelLoader.java

@@ -0,0 +1,121 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2019. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.client.render;
+
+import com.google.common.collect.ImmutableMap;
+import dan200.computercraft.ComputerCraft;
+import net.minecraft.client.renderer.block.model.IBakedModel;
+import net.minecraft.client.renderer.texture.TextureAtlasSprite;
+import net.minecraft.client.renderer.vertex.VertexFormat;
+import net.minecraft.client.resources.IResourceManager;
+import net.minecraft.util.ResourceLocation;
+import net.minecraftforge.client.model.ICustomModelLoader;
+import net.minecraftforge.client.model.IModel;
+import net.minecraftforge.client.model.ModelLoaderRegistry;
+import net.minecraftforge.common.model.IModelState;
+
+import javax.annotation.Nonnull;
+import java.util.function.Function;
+
+public final class TurtleModelLoader implements ICustomModelLoader
+{
+    private static final ResourceLocation NORMAL_TURTLE_MODEL = new ResourceLocation( ComputerCraft.MOD_ID, "block/turtle" );
+    private static final ResourceLocation ADVANCED_TURTLE_MODEL = new ResourceLocation( ComputerCraft.MOD_ID, "block/advanced_turtle" );
+    private static final ResourceLocation COLOUR_TURTLE_MODEL = new ResourceLocation( ComputerCraft.MOD_ID, "block/turtle_white" );
+
+    public static final TurtleModelLoader INSTANCE = new TurtleModelLoader();
+
+    private TurtleModelLoader()
+    {
+    }
+
+    @Override
+    public void onResourceManagerReload( @Nonnull IResourceManager manager )
+    {
+    }
+
+    @Override
+    public boolean accepts( @Nonnull ResourceLocation name )
+    {
+        return name.getNamespace().equals( ComputerCraft.MOD_ID )
+            && (name.getPath().equals( "turtle" ) || name.getPath().equals( "turtle_advanced" ));
+    }
+
+    @Nonnull
+    @Override
+    public IModel loadModel( @Nonnull ResourceLocation name ) throws Exception
+    {
+        if( name.getNamespace().equals( ComputerCraft.MOD_ID ) )
+        {
+            IModel colourModel = ModelLoaderRegistry.getModel( COLOUR_TURTLE_MODEL );
+            switch( name.getPath() )
+            {
+                case "turtle":
+                    return new TurtleModel( ModelLoaderRegistry.getModel( NORMAL_TURTLE_MODEL ), colourModel );
+                case "turtle_advanced":
+                    return new TurtleModel( ModelLoaderRegistry.getModel( ADVANCED_TURTLE_MODEL ), colourModel );
+            }
+        }
+
+        throw new IllegalStateException( "Loader does not accept " + name );
+    }
+
+    private static final class TurtleModel implements IModel
+    {
+        private final IModel family;
+        private final IModel colour;
+
+        private TurtleModel( IModel family, IModel colour )
+        {
+            this.family = family;
+            this.colour = colour;
+        }
+
+        @Nonnull
+        @Override
+        public IBakedModel bake( @Nonnull IModelState state, @Nonnull VertexFormat format, @Nonnull Function<ResourceLocation, TextureAtlasSprite> function )
+        {
+            return new TurtleSmartItemModel(
+                family.bake( state, format, function ),
+                colour.bake( state, format, function )
+            );
+        }
+
+        private TurtleModel copy( IModel family, IModel colour )
+        {
+            return this.family == family && this.colour == colour ? this : new TurtleModel( family, colour );
+        }
+
+        @Nonnull
+        @Override
+        public IModel smoothLighting( boolean value )
+        {
+            return copy( family.smoothLighting( value ), colour.smoothLighting( value ) );
+        }
+
+        @Nonnull
+        @Override
+        public IModel gui3d( boolean value )
+        {
+            return copy( family.gui3d( value ), colour.gui3d( value ) );
+        }
+
+        @Nonnull
+        @Override
+        public IModel uvlock( boolean value )
+        {
+            return copy( family.uvlock( value ), colour.uvlock( value ) );
+        }
+
+        @Nonnull
+        @Override
+        public IModel retexture( ImmutableMap<String, String> textures )
+        {
+            return copy( family.retexture( textures ), colour.retexture( textures ) );
+        }
+    }
+}

src/main/java/dan200/computercraft/client/render/TurtleMultiModel.java

@@ -17,7 +17,7 @@ import net.minecraft.util.EnumFacing;
 import javax.annotation.Nonnull;
 import javax.vecmath.Matrix4f;
 import java.util.ArrayList;
-import java.util.HashMap;
+import java.util.EnumMap;
 import java.util.List;
 import java.util.Map;
 
@@ -30,8 +30,8 @@ public class TurtleMultiModel implements IBakedModel
     private final Matrix4f m_leftUpgradeTransform;
     private final IBakedModel m_rightUpgradeModel;
     private final Matrix4f m_rightUpgradeTransform;
-    private List<BakedQuad> m_generalQuads;
-    private Map<EnumFacing, List<BakedQuad>> m_faceQuads;
+    private List<BakedQuad> m_generalQuads = null;
+    private Map<EnumFacing, List<BakedQuad>> m_faceQuads = new EnumMap<>( EnumFacing.class );
 
     public TurtleMultiModel( IBakedModel baseModel, IBakedModel overlayModel, Matrix4f generalTransform, IBakedModel leftUpgradeModel, Matrix4f leftUpgradeTransform, IBakedModel rightUpgradeModel, Matrix4f rightUpgradeTransform )
     {
@@ -43,8 +43,6 @@ public class TurtleMultiModel implements IBakedModel
         m_rightUpgradeModel = rightUpgradeModel;
         m_rightUpgradeTransform = rightUpgradeTransform;
         m_generalTransform = generalTransform;
-        m_generalQuads = null;
-        m_faceQuads = new HashMap<>();
     }
 
     @Nonnull

src/main/java/dan200/computercraft/client/render/TurtleSmartItemModel.java

@@ -9,7 +9,6 @@ package dan200.computercraft.client.render;
 import com.google.common.base.Objects;
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.api.turtle.TurtleSide;
-import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.turtle.items.ItemTurtleBase;
 import dan200.computercraft.shared.util.Holiday;
 import dan200.computercraft.shared.util.HolidayUtil;
@@ -17,15 +16,11 @@ import net.minecraft.block.state.IBlockState;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.block.model.*;
 import net.minecraft.client.renderer.texture.TextureAtlasSprite;
-import net.minecraft.client.resources.IResourceManager;
 import net.minecraft.entity.EntityLivingBase;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.EnumFacing;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.world.World;
-import net.minecraftforge.client.resource.IResourceType;
-import net.minecraftforge.client.resource.ISelectiveResourceReloadListener;
-import net.minecraftforge.client.resource.VanillaResourceType;
 import org.apache.commons.lang3.tuple.Pair;
 
 import javax.annotation.Nonnull;
@@ -34,9 +29,8 @@ import javax.vecmath.Matrix4f;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
-import java.util.function.Predicate;
 
-public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceReloadListener
+public class TurtleSmartItemModel implements IBakedModel
 {
     private static final Matrix4f s_identity, s_flip;
 
@@ -53,17 +47,15 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
 
     private static class TurtleModelCombination
     {
-        public final ComputerFamily m_family;
-        public final boolean m_colour;
-        public final ITurtleUpgrade m_leftUpgrade;
-        public final ITurtleUpgrade m_rightUpgrade;
-        public final ResourceLocation m_overlay;
-        public final boolean m_christmas;
-        public final boolean m_flip;
+        final boolean m_colour;
+        final ITurtleUpgrade m_leftUpgrade;
+        final ITurtleUpgrade m_rightUpgrade;
+        final ResourceLocation m_overlay;
+        final boolean m_christmas;
+        final boolean m_flip;
 
-        public TurtleModelCombination( ComputerFamily family, boolean colour, ITurtleUpgrade leftUpgrade, ITurtleUpgrade rightUpgrade, ResourceLocation overlay, boolean christmas, boolean flip )
+        TurtleModelCombination( boolean colour, ITurtleUpgrade leftUpgrade, ITurtleUpgrade rightUpgrade, ResourceLocation overlay, boolean christmas, boolean flip )
         {
-            m_family = family;
             m_colour = colour;
             m_leftUpgrade = leftUpgrade;
             m_rightUpgrade = rightUpgrade;
@@ -79,8 +71,7 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
             if( !(other instanceof TurtleModelCombination) ) return false;
 
             TurtleModelCombination otherCombo = (TurtleModelCombination) other;
-            return otherCombo.m_family == m_family &&
-                otherCombo.m_colour == m_colour &&
+            return otherCombo.m_colour == m_colour &&
                 otherCombo.m_leftUpgrade == m_leftUpgrade &&
                 otherCombo.m_rightUpgrade == m_rightUpgrade &&
                 Objects.equal( otherCombo.m_overlay, m_overlay ) &&
@@ -92,8 +83,7 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
         public int hashCode()
         {
             final int prime = 31;
-            int result = 1;
-            result = prime * result + m_family.hashCode();
+            int result = 0;
             result = prime * result + (m_colour ? 1 : 0);
             result = prime * result + (m_leftUpgrade != null ? m_leftUpgrade.hashCode() : 0);
             result = prime * result + (m_rightUpgrade != null ? m_rightUpgrade.hashCode() : 0);
@@ -104,14 +94,18 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
         }
     }
 
+    private final IBakedModel familyModel;
+    private final IBakedModel colourModel;
+
     private HashMap<TurtleModelCombination, IBakedModel> m_cachedModels;
     private ItemOverrideList m_overrides;
-    private final TurtleModelCombination m_defaultCombination;
 
-    public TurtleSmartItemModel()
+    public TurtleSmartItemModel( IBakedModel familyModel, IBakedModel colourModel )
     {
+        this.familyModel = familyModel;
+        this.colourModel = colourModel;
+
         m_cachedModels = new HashMap<>();
-        m_defaultCombination = new TurtleModelCombination( ComputerFamily.Normal, false, null, null, null, false, false );
         m_overrides = new ItemOverrideList( new ArrayList<>() )
         {
             @Nonnull
@@ -119,7 +113,6 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
             public IBakedModel handleItemState( @Nonnull IBakedModel originalModel, @Nonnull ItemStack stack, @Nullable World world, @Nullable EntityLivingBase entity )
             {
                 ItemTurtleBase turtle = (ItemTurtleBase) stack.getItem();
-                ComputerFamily family = turtle.getFamily( stack );
                 int colour = turtle.getColour( stack );
                 ITurtleUpgrade leftUpgrade = turtle.getUpgrade( stack, TurtleSide.Left );
                 ITurtleUpgrade rightUpgrade = turtle.getUpgrade( stack, TurtleSide.Right );
@@ -127,17 +120,11 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
                 boolean christmas = HolidayUtil.getCurrentHoliday() == Holiday.Christmas;
                 String label = turtle.getLabel( stack );
                 boolean flip = label != null && (label.equals( "Dinnerbone" ) || label.equals( "Grumm" ));
-                TurtleModelCombination combo = new TurtleModelCombination( family, colour != -1, leftUpgrade, rightUpgrade, overlay, christmas, flip );
-                if( m_cachedModels.containsKey( combo ) )
-                {
-                    return m_cachedModels.get( combo );
-                }
-                else
-                {
-                    IBakedModel model = buildModel( combo );
-                    m_cachedModels.put( combo, model );
-                    return model;
-                }
+                TurtleModelCombination combo = new TurtleModelCombination( colour != -1, leftUpgrade, rightUpgrade, overlay, christmas, flip );
+
+                IBakedModel model = m_cachedModels.get( combo );
+                if( model == null ) m_cachedModels.put( combo, model = buildModel( combo ) );
+                return model;
             }
         };
     }
@@ -149,23 +136,17 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
         return m_overrides;
     }
 
-    @Override
-    public void onResourceManagerReload( @Nonnull IResourceManager resourceManager, @Nonnull Predicate<IResourceType> resourcePredicate )
-    {
-        if( resourcePredicate.test( VanillaResourceType.MODELS ) ) m_cachedModels.clear();
-    }
-
     private IBakedModel buildModel( TurtleModelCombination combo )
     {
         Minecraft mc = Minecraft.getMinecraft();
         ModelManager modelManager = mc.getRenderItem().getItemModelMesher().getModelManager();
-        ModelResourceLocation baseModelLocation = TileEntityTurtleRenderer.getTurtleModel( combo.m_family, combo.m_colour );
-        ModelResourceLocation overlayModelLocation = TileEntityTurtleRenderer.getTurtleOverlayModel( combo.m_family, combo.m_overlay, combo.m_christmas );
-        IBakedModel baseModel = modelManager.getModel( baseModelLocation );
-        IBakedModel overlayModel = (overlayModelLocation != null) ? modelManager.getModel( overlayModelLocation ) : null;
+        ModelResourceLocation overlayModelLocation = TileEntityTurtleRenderer.getTurtleOverlayModel( combo.m_overlay, combo.m_christmas );
+
+        IBakedModel baseModel = combo.m_colour ? colourModel : familyModel;
+        IBakedModel overlayModel = overlayModelLocation != null ? modelManager.getModel( overlayModelLocation ) : null;
         Matrix4f transform = combo.m_flip ? s_flip : s_identity;
-        Pair<IBakedModel, Matrix4f> leftModel = (combo.m_leftUpgrade != null) ? combo.m_leftUpgrade.getModel( null, TurtleSide.Left ) : null;
-        Pair<IBakedModel, Matrix4f> rightModel = (combo.m_rightUpgrade != null) ? combo.m_rightUpgrade.getModel( null, TurtleSide.Right ) : null;
+        Pair<IBakedModel, Matrix4f> leftModel = combo.m_leftUpgrade != null ? combo.m_leftUpgrade.getModel( null, TurtleSide.Left ) : null;
+        Pair<IBakedModel, Matrix4f> rightModel = combo.m_rightUpgrade != null ? combo.m_rightUpgrade.getModel( null, TurtleSide.Right ) : null;
         if( leftModel != null && rightModel != null )
         {
             return new TurtleMultiModel( baseModel, overlayModel, transform, leftModel.getLeft(), leftModel.getRight(), rightModel.getLeft(), rightModel.getRight() );
@@ -184,38 +165,36 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
         }
     }
 
-    // These should not be called:
-
     @Nonnull
     @Override
     public List<BakedQuad> getQuads( IBlockState state, EnumFacing facing, long rand )
     {
-        return getDefaultModel().getQuads( state, facing, rand );
+        return familyModel.getQuads( state, facing, rand );
     }
 
     @Override
     public boolean isAmbientOcclusion()
     {
-        return getDefaultModel().isAmbientOcclusion();
+        return familyModel.isAmbientOcclusion();
     }
 
     @Override
     public boolean isGui3d()
     {
-        return getDefaultModel().isGui3d();
+        return familyModel.isGui3d();
     }
 
     @Override
     public boolean isBuiltInRenderer()
     {
-        return getDefaultModel().isBuiltInRenderer();
+        return familyModel.isBuiltInRenderer();
     }
 
     @Nonnull
     @Override
     public TextureAtlasSprite getParticleTexture()
     {
-        return getDefaultModel().getParticleTexture();
+        return familyModel.getParticleTexture();
     }
 
     @Nonnull
@@ -223,18 +202,7 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
     @Deprecated
     public ItemCameraTransforms getItemCameraTransforms()
     {
-        return getDefaultModel().getItemCameraTransforms();
+        return familyModel.getItemCameraTransforms();
     }
 
-    private IBakedModel getDefaultModel()
-    {
-        IBakedModel model = m_cachedModels.get( m_defaultCombination );
-        if( model == null )
-        {
-            model = buildModel( m_defaultCombination );
-            m_cachedModels.put( m_defaultCombination, model );
-        }
-
-        return model;
-    }
 }

src/main/java/dan200/computercraft/core/apis/AddressPredicate.java

@@ -20,7 +20,7 @@ import java.util.regex.Pattern;
  */
 public class AddressPredicate
 {
-    private static class HostRange
+    private static final class HostRange
     {
         private final byte[] min;
         private final byte[] max;
@@ -69,7 +69,10 @@ public class AddressPredicate
                 }
                 catch( NumberFormatException e )
                 {
-                    ComputerCraft.log.warn( "Cannot parse CIDR size from {} ({})", filter, prefixSizeStr );
+                    ComputerCraft.log.error(
+                        "Malformed http whitelist/blacklist entry '{}': Cannot extract size of CIDR mask from '{}'.",
+                        filter, prefixSizeStr
+                    );
                     continue;
                 }
 
@@ -80,7 +83,10 @@ public class AddressPredicate
                 }
                 catch( IllegalArgumentException e )
                 {
-                    ComputerCraft.log.warn( "Cannot parse IP address from {} ({})", filter, addressStr );
+                    ComputerCraft.log.error(
+                        "Malformed http whitelist/blacklist entry '{}': Cannot extract IP address from '{}'.",
+                        filter, prefixSizeStr
+                    );
                     continue;
                 }
 

src/main/java/dan200/computercraft/core/apis/ApiFactories.java

@@ -6,13 +6,13 @@
 
 package dan200.computercraft.core.apis;
 
-import com.google.common.base.Preconditions;
 import dan200.computercraft.api.lua.ILuaAPIFactory;
 
 import javax.annotation.Nonnull;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.LinkedHashSet;
+import java.util.Objects;
 
 public final class ApiFactories
 {
@@ -25,7 +25,7 @@ public final class ApiFactories
 
     public static void register( @Nonnull ILuaAPIFactory factory )
     {
-        Preconditions.checkNotNull( factory, "provider cannot be null" );
+        Objects.requireNonNull( factory, "provider cannot be null" );
         factories.add( factory );
     }
 

src/main/java/dan200/computercraft/core/apis/ComputerAccess.java

@@ -6,12 +6,10 @@
 
 package dan200.computercraft.core.apis;
 
-import com.google.common.base.Preconditions;
 import dan200.computercraft.api.filesystem.IMount;
 import dan200.computercraft.api.filesystem.IWritableMount;
 import dan200.computercraft.api.peripheral.IComputerAccess;
-import dan200.computercraft.core.computer.Computer;
-import dan200.computercraft.core.computer.IComputerOwned;
+import dan200.computercraft.api.peripheral.IWorkMonitor;
 import dan200.computercraft.core.filesystem.FileSystem;
 import dan200.computercraft.core.filesystem.FileSystemException;
 
@@ -21,22 +19,22 @@ import java.util.HashSet;
 import java.util.Objects;
 import java.util.Set;
 
-public abstract class ComputerAccess implements IComputerAccess, IComputerOwned
+public abstract class ComputerAccess implements IComputerAccess
 {
     private final IAPIEnvironment m_environment;
     private final Set<String> m_mounts = new HashSet<>();
 
-    protected ComputerAccess( IAPIEnvironment m_environment )
+    protected ComputerAccess( IAPIEnvironment environment )
     {
-        this.m_environment = m_environment;
+        this.m_environment = environment;
     }
 
     public void unmountAll()
     {
         FileSystem fileSystem = m_environment.getFileSystem();
-        for( String m_mount : m_mounts )
+        for( String mount : m_mounts )
         {
-            fileSystem.unmount( m_mount );
+            fileSystem.unmount( mount );
         }
         m_mounts.clear();
     }
@@ -122,15 +120,15 @@ public abstract class ComputerAccess implements IComputerAccess, IComputerOwned
     @Override
     public void queueEvent( @Nonnull final String event, final Object[] arguments )
     {
-        Preconditions.checkNotNull( event, "event cannot be null" );
+        Objects.requireNonNull( event, "event cannot be null" );
         m_environment.queueEvent( event, arguments );
     }
 
     @Nullable
     @Override
-    public Computer getComputer()
+    public IWorkMonitor getMainThreadMonitor()
     {
-        return m_environment.getComputer();
+        return m_environment.getMainThreadMonitor();
     }
 
     private String findFreeLocation( String desiredLoc )

src/main/java/dan200/computercraft/core/apis/FSAPI.java

@@ -34,18 +34,16 @@ public class FSAPI implements ILuaAPI
     private IAPIEnvironment m_env;
     private FileSystem m_fileSystem;
 
-    public FSAPI( IAPIEnvironment _env )
+    public FSAPI( IAPIEnvironment env )
     {
-        m_env = _env;
+        m_env = env;
         m_fileSystem = null;
     }
 
     @Override
     public String[] getNames()
     {
-        return new String[] {
-            "fs"
-        };
+        return new String[] { "fs" };
     }
 
     @Override
@@ -353,10 +351,8 @@ public class FSAPI implements ILuaAPI
                 return new Object[] { FileSystem.getDirectory( path ) };
             }
             default:
-            {
-                assert (false);
+                assert false;
                 return null;
-            }
         }
     }
 }

src/main/java/dan200/computercraft/core/apis/HTTPAPI.java

@@ -42,9 +42,7 @@ public class HTTPAPI implements ILuaAPI
     @Override
     public String[] getNames()
     {
-        return new String[] {
-            "http"
-        };
+        return new String[] { "http" };
     }
 
     @Override
@@ -83,6 +81,7 @@ public class HTTPAPI implements ILuaAPI
     }
 
     @Override
+    @SuppressWarnings( "resource" )
     public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] args ) throws LuaException
     {
         switch( method )
@@ -95,7 +94,7 @@ public class HTTPAPI implements ILuaAPI
 
                 if( args.length >= 1 && args[0] instanceof Map )
                 {
-                    Map<?, ?> options = (Map) args[0];
+                    Map<?, ?> options = (Map<?, ?>) args[0];
                     address = getStringField( options, "url" );
                     postString = optStringField( options, "body", null );
                     headerTable = optTableField( options, "headers", Collections.emptyMap() );
@@ -135,7 +134,6 @@ public class HTTPAPI implements ILuaAPI
                 try
                 {
                     URI uri = HttpRequest.checkUri( address );
-
                     HttpRequest request = new HttpRequest( requests, m_apiEnvironment, address, postString, headers, binary, redirect );
 
                     long requestBody = request.body().readableBytes() + HttpRequest.getHeaderSize( headers );
@@ -199,9 +197,7 @@ public class HTTPAPI implements ILuaAPI
                 }
             }
             default:
-            {
                 return null;
-            }
         }
     }
 
@@ -209,14 +205,14 @@ public class HTTPAPI implements ILuaAPI
     private static HttpHeaders getHeaders( @Nonnull Map<?, ?> headerTable ) throws LuaException
     {
         HttpHeaders headers = new DefaultHttpHeaders();
-        for( Object key : headerTable.keySet() )
+        for( Map.Entry<?, ?> entry : headerTable.entrySet() )
         {
-            Object value = headerTable.get( key );
-            if( key instanceof String && value instanceof String )
+            Object value = entry.getValue();
+            if( entry.getKey() instanceof String && value instanceof String )
             {
                 try
                 {
-                    headers.add( (String) key, value );
+                    headers.add( (String) entry.getKey(), value );
                 }
                 catch( IllegalArgumentException e )
                 {

src/main/java/dan200/computercraft/core/apis/IAPIEnvironment.java

@@ -7,27 +7,33 @@
 package dan200.computercraft.core.apis;
 
 import dan200.computercraft.api.peripheral.IPeripheral;
-import dan200.computercraft.core.computer.Computer;
+import dan200.computercraft.api.peripheral.IWorkMonitor;
+import dan200.computercraft.core.computer.ComputerSide;
 import dan200.computercraft.core.computer.IComputerEnvironment;
-import dan200.computercraft.core.computer.IComputerOwned;
 import dan200.computercraft.core.filesystem.FileSystem;
 import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.core.tracking.TrackingField;
 
-public interface IAPIEnvironment extends IComputerOwned
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+public interface IAPIEnvironment
 {
+    @FunctionalInterface
     interface IPeripheralChangeListener
     {
-        void onPeripheralChanged( int side, IPeripheral newPeripheral );
+        void onPeripheralChanged( ComputerSide side, @Nullable IPeripheral newPeripheral );
     }
 
-    @Override
-    Computer getComputer();
-
     int getComputerID();
 
+    @Nonnull
     IComputerEnvironment getComputerEnvironment();
 
+    @Nonnull
+    IWorkMonitor getMainThreadMonitor();
+
+    @Nonnull
     Terminal getTerminal();
 
     FileSystem getFileSystem();
@@ -38,29 +44,30 @@ public interface IAPIEnvironment extends IComputerOwned
 
     void queueEvent( String event, Object[] args );
 
-    void setOutput( int side, int output );
+    void setOutput( ComputerSide side, int output );
 
-    int getOutput( int side );
+    int getOutput( ComputerSide side );
 
-    int getInput( int side );
+    int getInput( ComputerSide side );
 
-    void setBundledOutput( int side, int output );
+    void setBundledOutput( ComputerSide side, int output );
 
-    int getBundledOutput( int side );
+    int getBundledOutput( ComputerSide side );
 
-    int getBundledInput( int side );
+    int getBundledInput( ComputerSide side );
 
-    void setPeripheralChangeListener( IPeripheralChangeListener listener );
+    void setPeripheralChangeListener( @Nullable IPeripheralChangeListener listener );
 
-    IPeripheral getPeripheral( int side );
+    @Nullable
+    IPeripheral getPeripheral( ComputerSide side );
 
     String getLabel();
 
-    void setLabel( String label );
+    void setLabel( @Nullable String label );
 
-    void addTrackingChange( TrackingField field, long change );
+    void addTrackingChange( @Nonnull TrackingField field, long change );
 
-    default void addTrackingChange( TrackingField field )
+    default void addTrackingChange( @Nonnull TrackingField field )
     {
         addTrackingChange( field, 1 );
     }

src/main/java/dan200/computercraft/core/apis/ILuaAPI.java

@@ -10,12 +10,14 @@ package dan200.computercraft.core.apis;
  * This exists purely to ensure binary compatibility.
  *
  * @see dan200.computercraft.api.lua.ILuaAPI
+ * @deprecated Use the version in the public API. Only exists for compatibility with CCEmuX.
  */
 @Deprecated
 public interface ILuaAPI extends dan200.computercraft.api.lua.ILuaAPI
 {
     void advance( double v );
 
+    @Override
     default void update()
     {
         advance( 0.05 );

src/main/java/dan200/computercraft/core/apis/LuaDateTime.java

@@ -0,0 +1,281 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2019. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.core.apis;
+
+import dan200.computercraft.api.lua.LuaException;
+
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+import java.time.ZoneOffset;
+import java.time.format.DateTimeFormatterBuilder;
+import java.time.format.TextStyle;
+import java.time.temporal.*;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.LongUnaryOperator;
+
+final class LuaDateTime
+{
+    private LuaDateTime()
+    {
+    }
+
+    static void format( DateTimeFormatterBuilder formatter, String format, ZoneOffset offset ) throws LuaException
+    {
+        for( int i = 0; i < format.length(); )
+        {
+            char c;
+            switch( c = format.charAt( i++ ) )
+            {
+                case '\n':
+                    formatter.appendLiteral( '\n' );
+                    break;
+                default:
+                    formatter.appendLiteral( c );
+                    break;
+                case '%':
+                    if( i >= format.length() ) break;
+                    switch( c = format.charAt( i++ ) )
+                    {
+                        default:
+                            throw new LuaException( "bad argument #1: invalid conversion specifier '%" + c + "'" );
+
+                        case '%':
+                            formatter.appendLiteral( '%' );
+                            break;
+                        case 'a':
+                            formatter.appendText( ChronoField.DAY_OF_WEEK, TextStyle.SHORT );
+                            break;
+                        case 'A':
+                            formatter.appendText( ChronoField.DAY_OF_WEEK, TextStyle.FULL );
+                            break;
+                        case 'b':
+                        case 'h':
+                            formatter.appendText( ChronoField.MONTH_OF_YEAR, TextStyle.SHORT );
+                            break;
+                        case 'B':
+                            formatter.appendText( ChronoField.MONTH_OF_YEAR, TextStyle.FULL );
+                            break;
+                        case 'c':
+                            format( formatter, "%a %b %e %H:%M:%S %Y", offset );
+                            break;
+                        case 'C':
+                            formatter.appendValueReduced( CENTURY, 2, 2, 0 );
+                            break;
+                        case 'd':
+                            formatter.appendValue( ChronoField.DAY_OF_MONTH, 2 );
+                            break;
+                        case 'D':
+                        case 'x':
+                            format( formatter, "%m/%d/%y", offset );
+                            break;
+                        case 'e':
+                            formatter.padNext( 2 ).appendValue( ChronoField.DAY_OF_MONTH );
+                            break;
+                        case 'F':
+                            format( formatter, "%Y-%m-%d", offset );
+                            break;
+                        case 'g':
+                            formatter.appendValueReduced( IsoFields.WEEK_BASED_YEAR, 2, 2, 0 );
+                            break;
+                        case 'G':
+                            formatter.appendValue( IsoFields.WEEK_BASED_YEAR );
+                            break;
+                        case 'H':
+                            formatter.appendValue( ChronoField.HOUR_OF_DAY, 2 );
+                            break;
+                        case 'I':
+                            formatter.appendValue( ChronoField.HOUR_OF_AMPM );
+                            break;
+                        case 'j':
+                            formatter.appendValue( ChronoField.DAY_OF_YEAR, 3 );
+                            break;
+                        case 'm':
+                            formatter.appendValue( ChronoField.MONTH_OF_YEAR, 2 );
+                            break;
+                        case 'M':
+                            formatter.appendValue( ChronoField.MINUTE_OF_HOUR, 2 );
+                            break;
+                        case 'n':
+                            formatter.appendLiteral( '\n' );
+                            break;
+                        case 'p':
+                            formatter.appendText( ChronoField.AMPM_OF_DAY );
+                            break;
+                        case 'r':
+                            format( formatter, "%I:%M:%S %p", offset );
+                            break;
+                        case 'R':
+                            format( formatter, "%H:%M", offset );
+                            break;
+                        case 'S':
+                            formatter.appendValue( ChronoField.SECOND_OF_MINUTE, 2 );
+                            break;
+                        case 't':
+                            formatter.appendLiteral( '\t' );
+                            break;
+                        case 'T':
+                        case 'X':
+                            format( formatter, "%H:%M:%S", offset );
+                            break;
+                        case 'u':
+                            formatter.appendValue( ChronoField.DAY_OF_WEEK );
+                            break;
+                        case 'U':
+                            formatter.appendValue( ChronoField.ALIGNED_WEEK_OF_YEAR, 2 );
+                            break;
+                        case 'V':
+                            formatter.appendValue( IsoFields.WEEK_OF_WEEK_BASED_YEAR, 2 );
+                            break;
+                        case 'w':
+                            formatter.appendValue( ZERO_WEEK );
+                            break;
+                        case 'W':
+                            formatter.appendValue( WeekFields.ISO.weekOfYear(), 2 );
+                            break;
+                        case 'y':
+                            formatter.appendValueReduced( ChronoField.YEAR, 2, 2, 0 );
+                            break;
+                        case 'Y':
+                            formatter.appendValue( ChronoField.YEAR );
+                            break;
+                        case 'z':
+                            formatter.appendOffset( "+HHMM", "+0000" );
+                            break;
+                        case 'Z':
+                            formatter.appendChronologyId();
+                            break;
+                    }
+            }
+        }
+    }
+
+    static long fromTable( Map<?, ?> table ) throws LuaException
+    {
+        int year = getField( table, "year", -1 );
+        int month = getField( table, "month", -1 );
+        int day = getField( table, "day", -1 );
+        int hour = getField( table, "hour", 12 );
+        int minute = getField( table, "min", 12 );
+        int second = getField( table, "sec", 12 );
+        LocalDateTime time = LocalDateTime.of( year, month, day, hour, minute, second );
+
+        Boolean isDst = getBoolField( table, "isdst" );
+        if( isDst != null )
+        {
+            boolean requireDst = isDst;
+            for( ZoneOffset possibleOffset : ZoneOffset.systemDefault().getRules().getValidOffsets( time ) )
+            {
+                Instant instant = time.toInstant( possibleOffset );
+                if( possibleOffset.getRules().getDaylightSavings( instant ).isZero() == requireDst )
+                {
+                    return instant.getEpochSecond();
+                }
+            }
+        }
+
+        ZoneOffset offset = ZoneOffset.systemDefault().getRules().getOffset( time );
+        return time.toInstant( offset ).getEpochSecond();
+    }
+
+    static Map<String, ?> toTable( TemporalAccessor date, ZoneId offset, Instant instant )
+    {
+        HashMap<String, Object> table = new HashMap<>( 9 );
+        table.put( "year", date.getLong( ChronoField.YEAR ) );
+        table.put( "month", date.getLong( ChronoField.MONTH_OF_YEAR ) );
+        table.put( "day", date.getLong( ChronoField.DAY_OF_MONTH ) );
+        table.put( "hour", date.getLong( ChronoField.HOUR_OF_DAY ) );
+        table.put( "min", date.getLong( ChronoField.MINUTE_OF_HOUR ) );
+        table.put( "sec", date.getLong( ChronoField.SECOND_OF_MINUTE ) );
+        table.put( "wday", date.getLong( WeekFields.SUNDAY_START.dayOfWeek() ) );
+        table.put( "yday", date.getLong( ChronoField.DAY_OF_YEAR ) );
+        table.put( "isdst", offset.getRules().isDaylightSavings( instant ) );
+        return table;
+    }
+
+    private static int getField( Map<?, ?> table, String field, int def ) throws LuaException
+    {
+        Object value = table.get( field );
+        if( value instanceof Number ) return ((Number) value).intValue();
+        if( def < 0 ) throw new LuaException( "field \"" + field + "\" missing in date table" );
+        return def;
+    }
+
+    private static Boolean getBoolField( Map<?, ?> table, String field ) throws LuaException
+    {
+        Object value = table.get( field );
+        if( value instanceof Boolean || value == null ) return (Boolean) value;
+        throw new LuaException( "field \"" + field + "\" missing in date table" );
+    }
+
+    private static final TemporalField CENTURY = map( ChronoField.YEAR, ValueRange.of( 0, 6 ), x -> (x / 100) % 100 );
+    private static final TemporalField ZERO_WEEK = map( WeekFields.SUNDAY_START.dayOfWeek(), ValueRange.of( 0, 6 ), x -> x - 1 );
+
+    private static TemporalField map( TemporalField field, ValueRange range, LongUnaryOperator convert )
+    {
+        return new TemporalField()
+        {
+            private final ValueRange range = ValueRange.of( 0, 99 );
+
+            @Override
+            public TemporalUnit getBaseUnit()
+            {
+                return field.getBaseUnit();
+            }
+
+            @Override
+            public TemporalUnit getRangeUnit()
+            {
+                return field.getRangeUnit();
+            }
+
+            @Override
+            public ValueRange range()
+            {
+                return range;
+            }
+
+            @Override
+            public boolean isDateBased()
+            {
+                return field.isDateBased();
+            }
+
+            @Override
+            public boolean isTimeBased()
+            {
+                return field.isTimeBased();
+            }
+
+            @Override
+            public boolean isSupportedBy( TemporalAccessor temporal )
+            {
+                return field.isSupportedBy( temporal );
+            }
+
+            @Override
+            public ValueRange rangeRefinedBy( TemporalAccessor temporal )
+            {
+                return range;
+            }
+
+            @Override
+            public long getFrom( TemporalAccessor temporal )
+            {
+                return convert.applyAsLong( temporal.getLong( field ) );
+            }
+
+            @Override
+            @SuppressWarnings( "unchecked" )
+            public <R extends Temporal> R adjustInto( R temporal, long newValue )
+            {
+                return (R) temporal.with( field, newValue );
+            }
+        };
+    }
+}

src/main/java/dan200/computercraft/core/apis/OSAPI.java

@@ -12,6 +12,11 @@ import dan200.computercraft.api.lua.LuaException;
 import dan200.computercraft.shared.util.StringUtil;
 
 import javax.annotation.Nonnull;
+import java.time.Instant;
+import java.time.ZoneId;
+import java.time.ZoneOffset;
+import java.time.ZonedDateTime;
+import java.time.format.DateTimeFormatterBuilder;
 import java.util.*;
 
 import static dan200.computercraft.core.apis.ArgumentHelper.*;
@@ -31,20 +36,20 @@ public class OSAPI implements ILuaAPI
 
     private static class Timer
     {
-        public int m_ticksLeft;
+        int m_ticksLeft;
 
-        public Timer( int ticksLeft )
+        Timer( int ticksLeft )
         {
             m_ticksLeft = ticksLeft;
         }
     }
 
-    private class Alarm implements Comparable<Alarm>
+    private static class Alarm implements Comparable<Alarm>
     {
-        public final double m_time;
-        public final int m_day;
+        final double m_time;
+        final int m_day;
 
-        public Alarm( double time, int day )
+        Alarm( double time, int day )
         {
             m_time = time;
             m_day = day;
@@ -73,9 +78,7 @@ public class OSAPI implements ILuaAPI
     @Override
     public String[] getNames()
     {
-        return new String[] {
-            "os"
-        };
+        return new String[] { "os" };
     }
 
     @Override
@@ -110,7 +113,7 @@ public class OSAPI implements ILuaAPI
             {
                 Map.Entry<Integer, Timer> entry = it.next();
                 Timer timer = entry.getValue();
-                timer.m_ticksLeft = timer.m_ticksLeft - 1;
+                timer.m_ticksLeft--;
                 if( timer.m_ticksLeft <= 0 )
                 {
                     // Queue the "timer" event
@@ -184,11 +187,12 @@ public class OSAPI implements ILuaAPI
             "day",
             "cancelTimer",
             "cancelAlarm",
-            "epoch"
+            "epoch",
+            "date",
         };
     }
 
-    private float getTimeForCalendar( Calendar c )
+    private static float getTimeForCalendar( Calendar c )
     {
         float time = c.get( Calendar.HOUR_OF_DAY );
         time += c.get( Calendar.MINUTE ) / 60.0f;
@@ -196,9 +200,9 @@ public class OSAPI implements ILuaAPI
         return time;
     }
 
-    private int getDayForCalendar( Calendar c )
+    private static int getDayForCalendar( Calendar c )
     {
-        GregorianCalendar g = (c instanceof GregorianCalendar) ? (GregorianCalendar) c : new GregorianCalendar();
+        GregorianCalendar g = c instanceof GregorianCalendar ? (GregorianCalendar) c : new GregorianCalendar();
         int year = c.get( Calendar.YEAR );
         int day = 0;
         for( int y = 1970; y < year; y++ )
@@ -209,7 +213,7 @@ public class OSAPI implements ILuaAPI
         return day;
     }
 
-    private long getEpochForCalendar( Calendar c )
+    private static long getEpochForCalendar( Calendar c )
     {
         return c.getTime().getTime();
     }
@@ -219,12 +223,9 @@ public class OSAPI implements ILuaAPI
     {
         switch( method )
         {
-            case 0:
-            {
-                // queueEvent
+            case 0: // queueEvent
                 queueLuaEvent( getString( args, 0 ), trimArray( args, 1 ) );
                 return null;
-            }
             case 1:
             {
                 // startTimer
@@ -245,29 +246,20 @@ public class OSAPI implements ILuaAPI
                 }
                 synchronized( m_alarms )
                 {
-                    int day = (time > m_time) ? m_day : (m_day + 1);
+                    int day = time > m_time ? m_day : m_day + 1;
                     m_alarms.put( m_nextAlarmToken, new Alarm( time, day ) );
                     return new Object[] { m_nextAlarmToken++ };
                 }
             }
-            case 3:
-            {
-                // shutdown
+            case 3: // shutdown
                 m_apiEnvironment.shutdown();
                 return null;
-            }
-            case 4:
-            {
-                // reboot
+            case 4: // reboot
                 m_apiEnvironment.reboot();
                 return null;
-            }
             case 5:
-            case 6:
-            {
-                // computerID/getComputerID
+            case 6: // computerID/getComputerID
                 return new Object[] { getComputerID() };
-            }
             case 7:
             {
                 // setComputerLabel
@@ -286,19 +278,19 @@ public class OSAPI implements ILuaAPI
                 }
                 return null;
             }
-            case 10:
-            {
-                // clock
+            case 10: // clock
                 synchronized( m_timers )
                 {
                     return new Object[] { m_clock * 0.05 };
                 }
-            }
             case 11:
             {
                 // time
+                Object value = args.length > 0 ? args[0] : null;
+                if( value instanceof Map ) return new Object[] { LuaDateTime.fromTable( (Map<?, ?>) value ) };
+
                 String param = optString( args, 0, "ingame" );
-                switch( param )
+                switch( param.toLowerCase( Locale.ROOT ) )
                 {
                     case "utc":
                     {
@@ -326,7 +318,7 @@ public class OSAPI implements ILuaAPI
             {
                 // day
                 String param = optString( args, 0, "ingame" );
-                switch( param )
+                switch( param.toLowerCase( Locale.ROOT ) )
                 {
                     case "utc":
                     {
@@ -356,10 +348,7 @@ public class OSAPI implements ILuaAPI
                 int token = getInt( args, 0 );
                 synchronized( m_timers )
                 {
-                    if( m_timers.containsKey( token ) )
-                    {
-                        m_timers.remove( token );
-                    }
+                    m_timers.remove( token );
                 }
                 return null;
             }
@@ -369,18 +358,14 @@ public class OSAPI implements ILuaAPI
                 int token = getInt( args, 0 );
                 synchronized( m_alarms )
                 {
-                    if( m_alarms.containsKey( token ) )
-                    {
-                        m_alarms.remove( token );
-                    }
+                    m_alarms.remove( token );
                 }
                 return null;
             }
-            case 15:
+            case 15: // epoch
             {
-                // epoch
                 String param = optString( args, 0, "ingame" );
-                switch( param )
+                switch( param.toLowerCase( Locale.ROOT ) )
                 {
                     case "utc":
                     {
@@ -398,18 +383,41 @@ public class OSAPI implements ILuaAPI
                         // Get in-game epoch
                         synchronized( m_alarms )
                         {
-                            return new Object[] {
-                                m_day * 86400000 + (int) (m_time * 3600000.0f)
-                            };
+                            return new Object[] { m_day * 86400000 + (int) (m_time * 3600000.0f) };
                         }
                     default:
                         throw new LuaException( "Unsupported operation" );
                 }
             }
-            default:
+            case 16: // date
             {
-                return null;
+                String format = optString( args, 0, "%c" );
+                long time = optLong( args, 1, Instant.now().getEpochSecond() );
+
+                Instant instant = Instant.ofEpochSecond( time );
+                ZonedDateTime date;
+                ZoneOffset offset;
+                if( format.startsWith( "!" ) )
+                {
+                    offset = ZoneOffset.UTC;
+                    date = ZonedDateTime.ofInstant( instant, offset );
+                    format = format.substring( 1 );
+                }
+                else
+                {
+                    ZoneId id = ZoneId.systemDefault();
+                    offset = id.getRules().getOffset( instant );
+                    date = ZonedDateTime.ofInstant( instant, id );
+                }
+
+                if( format.equals( "*t" ) ) return new Object[] { LuaDateTime.toTable( date, offset, instant ) };
+
+                DateTimeFormatterBuilder formatter = new DateTimeFormatterBuilder();
+                LuaDateTime.format( formatter, format, offset );
+                return new Object[] { formatter.toFormatter( Locale.ROOT ).format( date ) };
             }
+            default:
+                return null;
         }
     }
 

src/main/java/dan200/computercraft/core/apis/PeripheralAPI.java

@@ -12,9 +12,7 @@ import dan200.computercraft.api.lua.ILuaAPI;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
 import dan200.computercraft.api.peripheral.IPeripheral;
-import dan200.computercraft.core.computer.Computer;
-import dan200.computercraft.core.computer.ComputerThread;
-import dan200.computercraft.core.computer.ITask;
+import dan200.computercraft.core.computer.ComputerSide;
 import dan200.computercraft.core.tracking.TrackingField;
 
 import javax.annotation.Nonnull;
@@ -38,7 +36,7 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
         private Map<String, Integer> m_methodMap;
         private boolean m_attached;
 
-        public PeripheralWrapper( IPeripheral peripheral, String side )
+        PeripheralWrapper( IPeripheral peripheral, String side )
         {
             super( m_environment );
             m_side = side;
@@ -47,8 +45,8 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
 
             m_type = peripheral.getType();
             m_methods = peripheral.getMethodNames();
-            assert (m_type != null);
-            assert (m_methods != null);
+            assert m_type != null;
+            assert m_methods != null;
 
             m_methodMap = new HashMap<>();
             for( int i = 0; i < m_methods.length; i++ )
@@ -231,9 +229,9 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
     private final PeripheralWrapper[] m_peripherals;
     private boolean m_running;
 
-    public PeripheralAPI( IAPIEnvironment _environment )
+    public PeripheralAPI( IAPIEnvironment environment )
     {
-        m_environment = _environment;
+        m_environment = environment;
         m_environment.setPeripheralChangeListener( this );
 
         m_peripherals = new PeripheralWrapper[6];
@@ -248,76 +246,33 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
     // IPeripheralChangeListener
 
     @Override
-    public void onPeripheralChanged( int side, IPeripheral newPeripheral )
+    public void onPeripheralChanged( ComputerSide side, IPeripheral newPeripheral )
     {
         synchronized( m_peripherals )
         {
-            if( m_peripherals[side] != null )
+            int index = side.ordinal();
+            if( m_peripherals[index] != null )
             {
                 // Queue a detachment
-                final PeripheralWrapper wrapper = m_peripherals[side];
-                ComputerThread.queueTask( new ITask()
-                {
-                    @Override
-                    public Computer getOwner()
-                    {
-                        return m_environment.getComputer();
-                    }
-
-                    @Override
-                    public void execute()
-                    {
-                        synchronized( m_peripherals )
-                        {
-                            if( wrapper.isAttached() )
-                            {
-                                wrapper.detach();
-                            }
-                        }
-                    }
-                }, null );
+                final PeripheralWrapper wrapper = m_peripherals[index];
+                if( wrapper.isAttached() ) wrapper.detach();
 
                 // Queue a detachment event
-                m_environment.queueEvent( "peripheral_detach", new Object[] { Computer.s_sideNames[side] } );
+                m_environment.queueEvent( "peripheral_detach", new Object[] { side.getName() } );
             }
 
             // Assign the new peripheral
-            if( newPeripheral != null )
-            {
-                m_peripherals[side] = new PeripheralWrapper( newPeripheral, Computer.s_sideNames[side] );
-            }
-            else
-            {
-                m_peripherals[side] = null;
-            }
+            m_peripherals[index] = newPeripheral == null ? null
+                : new PeripheralWrapper( newPeripheral, side.getName() );
 
-            if( m_peripherals[side] != null )
+            if( m_peripherals[index] != null )
             {
                 // Queue an attachment
-                final PeripheralWrapper wrapper = m_peripherals[side];
-                ComputerThread.queueTask( new ITask()
-                {
-                    @Override
-                    public Computer getOwner()
-                    {
-                        return m_environment.getComputer();
-                    }
-
-                    @Override
-                    public void execute()
-                    {
-                        synchronized( m_peripherals )
-                        {
-                            if( m_running && !wrapper.isAttached() )
-                            {
-                                wrapper.attach();
-                            }
-                        }
-                    }
-                }, null );
+                final PeripheralWrapper wrapper = m_peripherals[index];
+                if( m_running && !wrapper.isAttached() ) wrapper.attach();
 
                 // Queue an attachment event
-                m_environment.queueEvent( "peripheral", new Object[] { Computer.s_sideNames[side] } );
+                m_environment.queueEvent( "peripheral", new Object[] { side.getName() } );
             }
         }
     }
@@ -327,9 +282,7 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
     @Override
     public String[] getNames()
     {
-        return new String[] {
-            "peripheral"
-        };
+        return new String[] { "peripheral" };
     }
 
     @Override
@@ -341,10 +294,7 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
             for( int i = 0; i < 6; i++ )
             {
                 PeripheralWrapper wrapper = m_peripherals[i];
-                if( wrapper != null && !wrapper.isAttached() )
-                {
-                    wrapper.attach();
-                }
+                if( wrapper != null && !wrapper.isAttached() ) wrapper.attach();
             }
         }
     }
@@ -374,7 +324,7 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
             "isPresent",
             "getType",
             "getMethods",
-            "call"
+            "call",
         };
     }
 
@@ -387,16 +337,13 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
             {
                 // isPresent
                 boolean present = false;
-                int side = parseSide( args );
-                if( side >= 0 )
+                ComputerSide side = ComputerSide.valueOfInsensitive( getString( args, 0 ) );
+                if( side != null )
                 {
                     synchronized( m_peripherals )
                     {
-                        PeripheralWrapper p = m_peripherals[side];
-                        if( p != null )
-                        {
-                            present = true;
-                        }
+                        PeripheralWrapper p = m_peripherals[side.ordinal()];
+                        if( p != null ) present = true;
                     }
                 }
                 return new Object[] { present };
@@ -404,21 +351,13 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
             case 1:
             {
                 // getType
-                String type = null;
-                int side = parseSide( args );
-                if( side >= 0 )
+                ComputerSide side = ComputerSide.valueOfInsensitive( getString( args, 0 ) );
+                if( side != null )
                 {
                     synchronized( m_peripherals )
                     {
-                        PeripheralWrapper p = m_peripherals[side];
-                        if( p != null )
-                        {
-                            type = p.getType();
-                        }
-                    }
-                    if( type != null )
-                    {
-                        return new Object[] { type };
+                        PeripheralWrapper p = m_peripherals[side.ordinal()];
+                        if( p != null ) return new Object[] { p.getType() };
                     }
                 }
                 return null;
@@ -427,12 +366,12 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
             {
                 // getMethods
                 String[] methods = null;
-                int side = parseSide( args );
-                if( side >= 0 )
+                ComputerSide side = ComputerSide.valueOfInsensitive( getString( args, 0 ) );
+                if( side != null )
                 {
                     synchronized( m_peripherals )
                     {
-                        PeripheralWrapper p = m_peripherals[side];
+                        PeripheralWrapper p = m_peripherals[side.ordinal()];
                         if( p != null )
                         {
                             methods = p.getMethods();
@@ -453,16 +392,16 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
             case 3:
             {
                 // call
-                int side = parseSide( args );
+                ComputerSide side = ComputerSide.valueOfInsensitive( getString( args, 0 ) );
                 String methodName = getString( args, 1 );
                 Object[] methodArgs = Arrays.copyOfRange( args, 2, args.length );
 
-                if( side >= 0 )
+                if( side != null )
                 {
                     PeripheralWrapper p;
                     synchronized( m_peripherals )
                     {
-                        p = m_peripherals[side];
+                        p = m_peripherals[side.ordinal()];
                     }
                     if( p != null )
                     {
@@ -472,24 +411,7 @@ public class PeripheralAPI implements ILuaAPI, IAPIEnvironment.IPeripheralChange
                 throw new LuaException( "No peripheral attached" );
             }
             default:
-            {
                 return null;
-            }
         }
     }
-
-    // Privates
-
-    private int parseSide( Object[] args ) throws LuaException
-    {
-        String side = getString( args, 0 );
-        for( int n = 0; n < Computer.s_sideNames.length; n++ )
-        {
-            if( side.equals( Computer.s_sideNames[n] ) )
-            {
-                return n;
-            }
-        }
-        return -1;
-    }
 }

src/main/java/dan200/computercraft/core/apis/RedstoneAPI.java

@@ -9,7 +9,7 @@ package dan200.computercraft.core.apis;
 import dan200.computercraft.api.lua.ILuaAPI;
 import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
-import dan200.computercraft.core.computer.Computer;
+import dan200.computercraft.core.computer.ComputerSide;
 
 import javax.annotation.Nonnull;
 import java.util.HashMap;
@@ -29,9 +29,7 @@ public class RedstoneAPI implements ILuaAPI
     @Override
     public String[] getNames()
     {
-        return new String[] {
-            "rs", "redstone"
-        };
+        return new String[] { "rs", "redstone" };
     }
 
     @Nonnull
@@ -65,65 +63,49 @@ public class RedstoneAPI implements ILuaAPI
             {
                 // getSides
                 Map<Object, Object> table = new HashMap<>();
-                for( int i = 0; i < Computer.s_sideNames.length; i++ )
+                for( int i = 0; i < ComputerSide.NAMES.length; i++ )
                 {
-                    table.put( i + 1, Computer.s_sideNames[i] );
+                    table.put( i + 1, ComputerSide.NAMES[i] );
                 }
                 return new Object[] { table };
             }
             case 1:
             {
                 // setOutput
-                int side = parseSide( args );
+                ComputerSide side = parseSide( args );
                 boolean output = getBoolean( args, 1 );
                 m_environment.setOutput( side, output ? 15 : 0 );
                 return null;
             }
-            case 2:
-            {
-                // getOutput
-                int side = parseSide( args );
-                return new Object[] { m_environment.getOutput( side ) > 0 };
-            }
-            case 3:
-            {
-                // getInput
-                int side = parseSide( args );
-                return new Object[] { m_environment.getInput( side ) > 0 };
-            }
+            case 2: // getOutput
+                return new Object[] { m_environment.getOutput( parseSide( args ) ) > 0 };
+            case 3: // getInput
+                return new Object[] { m_environment.getInput( parseSide( args ) ) > 0 };
             case 4:
             {
                 // setBundledOutput
-                int side = parseSide( args );
+                ComputerSide side = parseSide( args );
                 int output = getInt( args, 1 );
                 m_environment.setBundledOutput( side, output );
                 return null;
             }
-            case 5:
-            {
-                // getBundledOutput
-                int side = parseSide( args );
-                return new Object[] { m_environment.getBundledOutput( side ) };
-            }
-            case 6:
-            {
-                // getBundledInput
-                int side = parseSide( args );
-                return new Object[] { m_environment.getBundledInput( side ) };
-            }
+            case 5: // getBundledOutput
+                return new Object[] { m_environment.getBundledOutput( parseSide( args ) ) };
+            case 6: // getBundledInput
+                return new Object[] { m_environment.getBundledInput( parseSide( args ) ) };
             case 7:
             {
                 // testBundledInput
-                int side = parseSide( args );
+                ComputerSide side = parseSide( args );
                 int mask = getInt( args, 1 );
                 int input = m_environment.getBundledInput( side );
-                return new Object[] { ((input & mask) == mask) };
+                return new Object[] { (input & mask) == mask };
             }
             case 8:
             case 9:
             {
                 // setAnalogOutput/setAnalogueOutput
-                int side = parseSide( args );
+                ComputerSide side = parseSide( args );
                 int output = getInt( args, 1 );
                 if( output < 0 || output > 15 )
                 {
@@ -133,36 +115,20 @@ public class RedstoneAPI implements ILuaAPI
                 return null;
             }
             case 10:
-            case 11:
-            {
-                // getAnalogOutput/getAnalogueOutput
-                int side = parseSide( args );
-                return new Object[] { m_environment.getOutput( side ) };
-            }
+            case 11: // getAnalogOutput/getAnalogueOutput
+                return new Object[] { m_environment.getOutput( parseSide( args ) ) };
             case 12:
-            case 13:
-            {
-                // getAnalogInput/getAnalogueInput
-                int side = parseSide( args );
-                return new Object[] { m_environment.getInput( side ) };
-            }
+            case 13: // getAnalogInput/getAnalogueInput
+                return new Object[] { m_environment.getInput( parseSide( args ) ) };
             default:
-            {
                 return null;
-            }
         }
     }
 
-    private int parseSide( Object[] args ) throws LuaException
+    private static ComputerSide parseSide( Object[] args ) throws LuaException
     {
-        String side = getString( args, 0 );
-        for( int n = 0; n < Computer.s_sideNames.length; n++ )
-        {
-            if( side.equals( Computer.s_sideNames[n] ) )
-            {
-                return n;
-            }
-        }
-        throw new LuaException( "Invalid side." );
+        ComputerSide side = ComputerSide.valueOfInsensitive( getString( args, 0 ) );
+        if( side == null ) throw new LuaException( "Invalid side." );
+        return side;
     }
 }

src/main/java/dan200/computercraft/core/apis/TermAPI.java

@@ -11,6 +11,7 @@ import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
 import dan200.computercraft.core.computer.IComputerEnvironment;
 import dan200.computercraft.core.terminal.Terminal;
+import dan200.computercraft.shared.util.Colour;
 import dan200.computercraft.shared.util.Palette;
 import org.apache.commons.lang3.ArrayUtils;
 
@@ -23,18 +24,16 @@ public class TermAPI implements ILuaAPI
     private final Terminal m_terminal;
     private final IComputerEnvironment m_environment;
 
-    public TermAPI( IAPIEnvironment _environment )
+    public TermAPI( IAPIEnvironment environment )
     {
-        m_terminal = _environment.getTerminal();
-        m_environment = _environment.getComputerEnvironment();
+        m_terminal = environment.getTerminal();
+        m_environment = environment.getComputerEnvironment();
     }
 
     @Override
     public String[] getNames()
     {
-        return new String[] {
-            "term"
-        };
+        return new String[] { "term" };
     }
 
     @Nonnull
@@ -65,6 +64,8 @@ public class TermAPI implements ILuaAPI
             "setPaletteColor",
             "getPaletteColour",
             "getPaletteColor",
+            "nativePaletteColour",
+            "nativePaletteColor",
             "getCursorBlink",
         };
     }
@@ -86,9 +87,7 @@ public class TermAPI implements ILuaAPI
 
     public static Object[] encodeColour( int colour ) throws LuaException
     {
-        return new Object[] {
-            1 << colour
-        };
+        return new Object[] { 1 << colour };
     }
 
     public static void setColour( Terminal terminal, int colour, double r, double g, double b )
@@ -108,16 +107,7 @@ public class TermAPI implements ILuaAPI
             case 0:
             {
                 // write
-                String text;
-                if( args.length > 0 && args[0] != null )
-                {
-                    text = args[0].toString();
-                }
-                else
-                {
-                    text = "";
-                }
-
+                String text = args.length > 0 && args[0] != null ? args[0].toString() : "";
                 synchronized( m_terminal )
                 {
                     m_terminal.write( text );
@@ -178,24 +168,18 @@ public class TermAPI implements ILuaAPI
                 }
                 return new Object[] { width, height };
             }
-            case 6:
-            {
-                // clear
+            case 6: // clear
                 synchronized( m_terminal )
                 {
                     m_terminal.clear();
                 }
                 return null;
-            }
-            case 7:
-            {
-                // clearLine
+            case 7: // clearLine
                 synchronized( m_terminal )
                 {
                     m_terminal.clearLine();
                 }
                 return null;
-            }
             case 8:
             case 9:
             {
@@ -219,23 +203,14 @@ public class TermAPI implements ILuaAPI
                 return null;
             }
             case 12:
-            case 13:
-            {
-                // isColour/isColor
+            case 13: // isColour/isColor
                 return new Object[] { m_environment.isColour() };
-            }
             case 14:
-            case 15:
-            {
-                // getTextColour/getTextColor
+            case 15: // getTextColour/getTextColor
                 return encodeColour( m_terminal.getTextColour() );
-            }
             case 16:
-            case 17:
-            {
-                // getBackgroundColour/getBackgroundColor
+            case 17: // getBackgroundColour/getBackgroundColor
                 return encodeColour( m_terminal.getBackgroundColour() );
-            }
             case 18:
             {
                 // blit
@@ -289,12 +264,23 @@ public class TermAPI implements ILuaAPI
                 return null;
             }
             case 23:
+            case 24:
+            {
+                // nativePaletteColour/nativePaletteColor
+                int colour = 15 - parseColour( args );
+                Colour c = Colour.fromInt( colour );
+
+                float[] rgb = c.getRGB();
+
+                Object[] rgbObj = new Object[rgb.length];
+                for( int i = 0; i < rgbObj.length; ++i ) rgbObj[i] = rgb[i];
+                return rgbObj;
+            }
+            case 25:
                 // getCursorBlink
                 return new Object[] { m_terminal.getCursorBlink() };
             default:
-            {
                 return null;
-            }
         }
     }
 

src/main/java/dan200/computercraft/core/apis/handles/ArrayByteChannel.java

@@ -6,13 +6,11 @@
 
 package dan200.computercraft.core.apis.handles;
 
-import com.google.common.base.Preconditions;
-
-import java.io.IOException;
 import java.nio.ByteBuffer;
 import java.nio.channels.ClosedChannelException;
 import java.nio.channels.NonWritableChannelException;
 import java.nio.channels.SeekableByteChannel;
+import java.util.Objects;
 
 /**
  * A seekable, readable byte channel which is backed by a simple byte array.
@@ -30,10 +28,10 @@ public class ArrayByteChannel implements SeekableByteChannel
     }
 
     @Override
-    public int read( ByteBuffer destination ) throws IOException
+    public int read( ByteBuffer destination ) throws ClosedChannelException
     {
         if( closed ) throw new ClosedChannelException();
-        Preconditions.checkNotNull( destination, "destination" );
+        Objects.requireNonNull( destination, "destination" );
 
         if( position >= backing.length ) return -1;
 
@@ -44,21 +42,21 @@ public class ArrayByteChannel implements SeekableByteChannel
     }
 
     @Override
-    public int write( ByteBuffer src ) throws IOException
+    public int write( ByteBuffer src ) throws ClosedChannelException
     {
         if( closed ) throw new ClosedChannelException();
         throw new NonWritableChannelException();
     }
 
     @Override
-    public long position() throws IOException
+    public long position() throws ClosedChannelException
     {
         if( closed ) throw new ClosedChannelException();
         return position;
     }
 
     @Override
-    public SeekableByteChannel position( long newPosition ) throws IOException
+    public SeekableByteChannel position( long newPosition ) throws ClosedChannelException
     {
         if( closed ) throw new ClosedChannelException();
         if( newPosition < 0 || newPosition > Integer.MAX_VALUE )
@@ -70,14 +68,14 @@ public class ArrayByteChannel implements SeekableByteChannel
     }
 
     @Override
-    public long size() throws IOException
+    public long size() throws ClosedChannelException
     {
         if( closed ) throw new ClosedChannelException();
         return backing.length;
     }
 
     @Override
-    public SeekableByteChannel truncate( long size ) throws IOException
+    public SeekableByteChannel truncate( long size ) throws ClosedChannelException
     {
         if( closed ) throw new ClosedChannelException();
         throw new NonWritableChannelException();

src/main/java/dan200/computercraft/core/apis/handles/BinaryReadableHandle.java

@@ -38,8 +38,8 @@ public class BinaryReadableHandle extends HandleGeneric
     public BinaryReadableHandle( ReadableByteChannel channel, Closeable closeable )
     {
         super( closeable );
-        this.m_reader = channel;
-        this.m_seekable = asSeekable( channel );
+        m_reader = channel;
+        m_seekable = asSeekable( channel );
     }
 
     public BinaryReadableHandle( ReadableByteChannel channel )
@@ -169,27 +169,42 @@ public class BinaryReadableHandle extends HandleGeneric
                 {
                     ByteArrayOutputStream stream = new ByteArrayOutputStream();
 
-                    boolean readAnything = false;
+                    boolean readAnything = false, readRc = false;
                     while( true )
                     {
                         single.clear();
-                        int r = m_reader.read( single );
-                        if( r == -1 ) break;
+                        int read = m_reader.read( single );
+                        if( read <= 0 )
+                        {
+                            // Nothing else to read, and we saw no \n. Return the array. If we saw a \r, then add it
+                            // back.
+                            if( readRc ) stream.write( '\r' );
+                            return readAnything ? new Object[] { stream.toByteArray() } : null;
+                        }
 
                         readAnything = true;
-                        byte b = single.get( 0 );
-                        if( b == '\n' )
+
+                        byte chr = single.get( 0 );
+                        if( chr == '\n' )
                         {
-                            if( withTrailing ) stream.write( b );
-                            break;
+                            if( withTrailing )
+                            {
+                                if( readRc ) stream.write( '\r' );
+                                stream.write( chr );
+                            }
+                            return new Object[] { stream.toByteArray() };
                         }
                         else
                         {
-                            stream.write( b );
+                            // We want to skip \r\n, but obviously need to include cases where \r is not followed by \n.
+                            // Note, this behaviour is non-standard compliant (strictly speaking we should have no
+                            // special logic for \r), but we preserve compatibility with EncodedReadableHandle and
+                            // previous behaviour of the io library.
+                            if( readRc ) stream.write( '\r' );
+                            readRc = chr == '\r';
+                            if( !readRc ) stream.write( chr );
                         }
                     }
-
-                    return readAnything ? new Object[] { stream.toByteArray() } : null;
                 }
                 catch( IOException e )
                 {
@@ -197,6 +212,7 @@ public class BinaryReadableHandle extends HandleGeneric
                 }
             }
             case 3: // close
+                checkOpen();
                 close();
                 return null;
             case 4: // seek

src/main/java/dan200/computercraft/core/apis/handles/BinaryWritableHandle.java

@@ -32,8 +32,8 @@ public class BinaryWritableHandle extends HandleGeneric
     public BinaryWritableHandle( WritableByteChannel channel, Closeable closeable )
     {
         super( closeable );
-        this.m_writer = channel;
-        this.m_seekable = asSeekable( channel );
+        m_writer = channel;
+        m_seekable = asSeekable( channel );
     }
 
     public BinaryWritableHandle( WritableByteChannel channel )
@@ -95,6 +95,7 @@ public class BinaryWritableHandle extends HandleGeneric
                     return null;
                 }
             case 2: // close
+                checkOpen();
                 close();
                 return null;
             case 3: // seek

src/main/java/dan200/computercraft/core/apis/handles/EncodedReadableHandle.java

@@ -32,7 +32,7 @@ public class EncodedReadableHandle extends HandleGeneric
     public EncodedReadableHandle( @Nonnull BufferedReader reader, @Nonnull Closeable closable )
     {
         super( closable );
-        this.m_reader = reader;
+        m_reader = reader;
     }
 
     public EncodedReadableHandle( @Nonnull BufferedReader reader )
@@ -84,7 +84,7 @@ public class EncodedReadableHandle extends HandleGeneric
                 checkOpen();
                 try
                 {
-                    StringBuilder result = new StringBuilder( "" );
+                    StringBuilder result = new StringBuilder();
                     String line = m_reader.readLine();
                     while( line != null )
                     {
@@ -152,6 +152,7 @@ public class EncodedReadableHandle extends HandleGeneric
                     return null;
                 }
             case 3: // close
+                checkOpen();
                 close();
                 return null;
             default:

src/main/java/dan200/computercraft/core/apis/handles/EncodedWritableHandle.java

@@ -27,7 +27,7 @@ public class EncodedWritableHandle extends HandleGeneric
     public EncodedWritableHandle( @Nonnull BufferedWriter writer, @Nonnull Closeable closable )
     {
         super( closable );
-        this.m_writer = writer;
+        m_writer = writer;
     }
 
     public EncodedWritableHandle( @Nonnull BufferedWriter writer )
@@ -93,6 +93,7 @@ public class EncodedWritableHandle extends HandleGeneric
                     return null;
                 }
             case 3: // close
+                checkOpen();
                 close();
                 return null;
             default:

src/main/java/dan200/computercraft/core/apis/handles/HandleGeneric.java

@@ -26,7 +26,7 @@ public abstract class HandleGeneric implements ILuaObject
 
     protected HandleGeneric( @Nonnull Closeable closable )
     {
-        this.m_closable = closable;
+        m_closable = closable;
     }
 
     protected void checkOpen() throws LuaException
@@ -37,8 +37,13 @@ public abstract class HandleGeneric implements ILuaObject
     protected final void close()
     {
         m_open = false;
-        IoUtil.closeQuietly( m_closable );
-        m_closable = null;
+
+        Closeable closeable = m_closable;
+        if( closeable != null )
+        {
+            IoUtil.closeQuietly( closeable );
+            m_closable = null;
+        }
     }
 
     /**
@@ -46,7 +51,7 @@ public abstract class HandleGeneric implements ILuaObject
      *
      * @param channel The channel to seek in
      * @param args    The Lua arguments to process, like Lua's {@code file:seek}.
-     * @return The new position of the file, or null if some error occured.
+     * @return The new position of the file, or null if some error occurred.
      * @throws LuaException If the arguments were invalid
      * @see <a href="https://www.lua.org/manual/5.1/manual.html#pdf-file:seek">{@code file:seek} in the Lua manual.</a>
      */

src/main/java/dan200/computercraft/core/apis/http/CheckUrl.java

@@ -31,7 +31,7 @@ public class CheckUrl extends Resource<CheckUrl>
         super( limiter );
         this.environment = environment;
         this.address = address;
-        this.host = uri.getHost();
+        host = uri.getHost();
     }
 
     public void run()

src/main/java/dan200/computercraft/core/apis/http/Resource.java

@@ -72,7 +72,8 @@ public abstract class Resource<T extends Resource<T>> implements Closeable
      */
     protected void dispose()
     {
-        @SuppressWarnings( "unchecked" ) T thisT = (T) this;
+        @SuppressWarnings( "unchecked" )
+        T thisT = (T) this;
         limiter.release( thisT );
     }
 
@@ -95,7 +96,8 @@ public abstract class Resource<T extends Resource<T>> implements Closeable
 
     public boolean queue( Consumer<T> task )
     {
-        @SuppressWarnings( "unchecked" ) T thisT = (T) this;
+        @SuppressWarnings( "unchecked" )
+        T thisT = (T) this;
         return limiter.queue( thisT, () -> task.accept( thisT ) );
     }
 
@@ -140,6 +142,6 @@ public abstract class Resource<T extends Resource<T>> implements Closeable
     public static void cleanup()
     {
         Reference<?> reference;
-        while( (reference = QUEUE.poll()) != null ) ((CloseReference) reference).resource.close();
+        while( (reference = QUEUE.poll()) != null ) ((CloseReference<?>) reference).resource.close();
     }
 }

src/main/java/dan200/computercraft/core/apis/http/ResourceGroup.java

@@ -32,7 +32,7 @@ public class ResourceGroup<T extends Resource<T>>
 
     public ResourceGroup()
     {
-        this.limit = ZERO;
+        limit = ZERO;
     }
 
     public void startup()

src/main/java/dan200/computercraft/core/apis/http/ResourceQueue.java

@@ -26,12 +26,14 @@ public class ResourceQueue<T extends Resource<T>> extends ResourceGroup<T>
     {
     }
 
+    @Override
     public synchronized void shutdown()
     {
         super.shutdown();
         pending.clear();
     }
 
+    @Override
     public synchronized boolean queue( Supplier<T> resource )
     {
         if( !active ) return false;
@@ -40,6 +42,7 @@ public class ResourceQueue<T extends Resource<T>> extends ResourceGroup<T>
         return true;
     }
 
+    @Override
     public synchronized void release( T resource )
     {
         super.release( resource );

src/main/java/dan200/computercraft/core/apis/http/request/HttpRequest.java

@@ -67,12 +67,12 @@ public class HttpRequest extends Resource<HttpRequest>
         super( limiter );
         this.environment = environment;
         this.address = address;
-        this.postBuffer = postText != null
+        postBuffer = postText != null
             ? Unpooled.wrappedBuffer( postText.getBytes( StandardCharsets.UTF_8 ) )
             : Unpooled.buffer( 0 );
         this.headers = headers;
         this.binary = binary;
-        this.redirects = new AtomicInteger( followRedirects ? MAX_REDIRECTS : 0 );
+        redirects = new AtomicInteger( followRedirects ? MAX_REDIRECTS : 0 );
 
         if( postText != null )
         {
@@ -113,6 +113,7 @@ public class HttpRequest extends Resource<HttpRequest>
     {
         // Validate the URL
         if( url.getScheme() == null ) throw new HTTPRequestException( "Must specify http or https" );
+        if( url.getHost() == null ) throw new HTTPRequestException( "URL malformed" );
 
         String scheme = url.getScheme().toLowerCase( Locale.ROOT );
         if( !scheme.equalsIgnoreCase( "http" ) && !scheme.equalsIgnoreCase( "https" ) )
@@ -239,6 +240,7 @@ public class HttpRequest extends Resource<HttpRequest>
         if( tryClose() ) environment.queueEvent( SUCCESS_EVENT, new Object[] { address, object } );
     }
 
+    @Override
     protected void dispose()
     {
         super.dispose();

src/main/java/dan200/computercraft/core/apis/http/request/HttpRequestHandler.java

@@ -37,7 +37,7 @@ public final class HttpRequestHandler extends SimpleChannelInboundHandler<HttpOb
     /**
      * Same as {@link io.netty.handler.codec.MessageAggregator}.
      */
-    private static final int DEFAULT_MAX_COMPOSITEBUFFER_COMPONENTS = 1024;
+    private static final int DEFAULT_MAX_COMPOSITE_BUFFER_COMPONENTS = 1024;
 
     private static final byte[] EMPTY_BYTES = new byte[0];
 
@@ -147,7 +147,7 @@ public final class HttpRequestHandler extends SimpleChannelInboundHandler<HttpOb
 
             if( responseBody == null )
             {
-                responseBody = ctx.alloc().compositeBuffer( DEFAULT_MAX_COMPOSITEBUFFER_COMPONENTS );
+                responseBody = ctx.alloc().compositeBuffer( DEFAULT_MAX_COMPOSITE_BUFFER_COMPONENTS );
             }
 
             ByteBuf partial = content.content();

src/main/java/dan200/computercraft/core/apis/http/websocket/Websocket.java

@@ -95,7 +95,7 @@ public class Websocket extends Resource<Websocket>
         {
             try
             {
-                uri = new URI( "ws://" + uri.toString() );
+                uri = new URI( "ws://" + uri );
             }
             catch( URISyntaxException e )
             {
@@ -161,7 +161,10 @@ public class Websocket extends Resource<Websocket>
                     }
                 } )
                 .remoteAddress( socketAddress )
-                .connect();
+                .connect()
+                .addListener( c -> {
+                    if( !c.isSuccess() ) failure( c.cause().getMessage() );
+                } );
 
             // Do an additional check for cancellation
             checkClosed();
@@ -183,7 +186,7 @@ public class Websocket extends Resource<Websocket>
 
         WebsocketHandle handle = new WebsocketHandle( this, channel );
         environment().queueEvent( SUCCESS_EVENT, new Object[] { address, handle } );
-        this.websocketHandle = createOwnerReference( handle );
+        websocketHandle = createOwnerReference( handle );
 
         checkClosed();
     }
@@ -213,7 +216,7 @@ public class Websocket extends Resource<Websocket>
         executorFuture = closeFuture( executorFuture );
         connectFuture = closeChannel( connectFuture );
 
-        WeakReference<WebsocketHandle> websocketHandleRef = this.websocketHandle;
+        WeakReference<WebsocketHandle> websocketHandleRef = websocketHandle;
         WebsocketHandle websocketHandle = websocketHandleRef == null ? null : websocketHandleRef.get();
         if( websocketHandle != null ) IoUtil.closeQuietly( websocketHandle );
         this.websocketHandle = null;

src/main/java/dan200/computercraft/core/apis/http/websocket/WebsocketHandle.java

@@ -24,6 +24,7 @@ import java.io.Closeable;
 import java.util.Arrays;
 
 import static dan200.computercraft.core.apis.ArgumentHelper.optBoolean;
+import static dan200.computercraft.core.apis.http.websocket.Websocket.CLOSE_EVENT;
 import static dan200.computercraft.core.apis.http.websocket.Websocket.MESSAGE_EVENT;
 
 public class WebsocketHandle implements ILuaObject, Closeable
@@ -53,15 +54,18 @@ public class WebsocketHandle implements ILuaObject, Closeable
         switch( method )
         {
             case 0: // receive
+                checkOpen();
                 while( true )
                 {
-                    checkOpen();
-
-                    Object[] event = context.pullEvent( MESSAGE_EVENT );
-                    if( event.length >= 3 && Objects.equal( event[1], websocket.address() ) )
+                    Object[] event = context.pullEvent( null );
+                    if( event.length >= 3 && Objects.equal( event[0], MESSAGE_EVENT ) && Objects.equal( event[1], websocket.address() ) )
                     {
                         return Arrays.copyOfRange( event, 2, event.length );
                     }
+                    else if( event.length >= 2 && Objects.equal( event[0], CLOSE_EVENT ) && Objects.equal( event[1], websocket.address() ) && closed )
+                    {
+                        return null;
+                    }
                 }
 
             case 1: // send

src/main/java/dan200/computercraft/core/apis/http/websocket/WebsocketHandler.java

@@ -83,6 +83,11 @@ public class WebsocketHandler extends SimpleChannelInboundHandler<Object>
             CloseWebSocketFrame closeFrame = (CloseWebSocketFrame) frame;
             websocket.close( closeFrame.statusCode(), closeFrame.reasonText() );
         }
+        else if( frame instanceof PingWebSocketFrame )
+        {
+            frame.content().retain();
+            ctx.channel().writeAndFlush( new PongWebSocketFrame( frame.content() ) );
+        }
     }
 
     @Override
@@ -108,6 +113,13 @@ public class WebsocketHandler extends SimpleChannelInboundHandler<Object>
             message = "Could not connect";
         }
 
-        websocket.failure( message );
+        if( handshaker.isHandshakeComplete() )
+        {
+            websocket.close( -1, message );
+        }
+        else
+        {
+            websocket.failure( message );
+        }
     }
 }

src/main/java/dan200/computercraft/core/computer/ApiWrapper.java

@@ -0,0 +1,68 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2019. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.core.computer;
+
+import dan200.computercraft.api.lua.ILuaAPI;
+import dan200.computercraft.api.lua.ILuaContext;
+import dan200.computercraft.api.lua.LuaException;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+
+/**
+ * A wrapper for {@link ILuaAPI}s which cleans up after a {@link ComputerSystem} when the computer is shutdown.
+ */
+final class ApiWrapper implements ILuaAPI
+{
+    private final ILuaAPI delegate;
+    private final ComputerSystem system;
+
+    ApiWrapper( ILuaAPI delegate, ComputerSystem system )
+    {
+        this.delegate = delegate;
+        this.system = system;
+    }
+
+    @Override
+    public String[] getNames()
+    {
+        return delegate.getNames();
+    }
+
+    @Override
+    public void startup()
+    {
+        delegate.startup();
+    }
+
+    @Override
+    public void update()
+    {
+        delegate.update();
+    }
+
+    @Override
+    public void shutdown()
+    {
+        delegate.shutdown();
+        system.unmountAll();
+    }
+
+    @Nonnull
+    @Override
+    public String[] getMethodNames()
+    {
+        return delegate.getMethodNames();
+    }
+
+    @Nullable
+    @Override
+    public Object[] callMethod( @Nonnull ILuaContext context, int method, @Nonnull Object[] arguments ) throws LuaException, InterruptedException
+    {
+        return delegate.callMethod( context, method, arguments );
+    }
+}

src/main/java/dan200/computercraft/core/computer/ComputerExecutor.java

@@ -0,0 +1,668 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2019. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.core.computer;
+
+import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.api.filesystem.IMount;
+import dan200.computercraft.api.filesystem.IWritableMount;
+import dan200.computercraft.api.lua.ILuaAPI;
+import dan200.computercraft.api.lua.ILuaAPIFactory;
+import dan200.computercraft.core.apis.*;
+import dan200.computercraft.core.filesystem.FileSystem;
+import dan200.computercraft.core.filesystem.FileSystemException;
+import dan200.computercraft.core.lua.CobaltLuaMachine;
+import dan200.computercraft.core.lua.ILuaMachine;
+import dan200.computercraft.core.lua.MachineResult;
+import dan200.computercraft.core.terminal.Terminal;
+import dan200.computercraft.core.tracking.Tracking;
+import dan200.computercraft.shared.util.Colour;
+import dan200.computercraft.shared.util.IoUtil;
+
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
+import java.io.InputStream;
+import java.util.ArrayDeque;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Queue;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.concurrent.locks.ReentrantLock;
+
+/**
+ * The main task queue and executor for a single computer. This handles turning on and off a computer, as well as
+ * running events.
+ *
+ * When the computer is instructed to turn on or off, or handle an event, we queue a task and register this to be
+ * executed on the {@link ComputerThread}. Note, as we may be starting many events in a single tick, the external
+ * cannot lock on anything which may be held for a long time.
+ *
+ * The executor is effectively composed of two separate queues. Firstly, we have a "single element" queue
+ * {@link #command} which determines which state the computer should transition too. This is set by
+ * {@link #queueStart()} and {@link #queueStop(boolean, boolean)}.
+ *
+ * When a computer is on, we simply push any events onto to the {@link #eventQueue}.
+ *
+ * Both queues are run from the {@link #work()} method, which tries to execute a command if one exists, or resumes the
+ * machine with an event otherwise.
+ *
+ * One final responsibility for the executor is calling {@link ILuaAPI#update()} every tick, via the {@link #tick()}
+ * method. This should only be called when the computer is actually on ({@link #isOn}).
+ */
+final class ComputerExecutor
+{
+    private static final int QUEUE_LIMIT = 256;
+
+    private static IMount romMount;
+    private static final Object romMountLock = new Object();
+
+    private final Computer computer;
+    private final List<ILuaAPI> apis = new ArrayList<>();
+    final TimeoutState timeout = new TimeoutState();
+
+    private FileSystem fileSystem;
+
+    private ILuaMachine machine;
+
+    /**
+     * Whether the computer is currently on. This is set to false when a shutdown starts, or when turning on completes
+     * (but just before the Lua machine is started).
+     *
+     * @see #isOnLock
+     */
+    private volatile boolean isOn = false;
+
+    /**
+     * The lock to acquire when you need to modify the "on state" of a computer.
+     *
+     * We hold this lock when running any command, and attempt to hold it when updating APIs. This ensures you don't
+     * update APIs while also starting/stopping them.
+     *
+     * @see #isOn
+     * @see #tick()
+     * @see #turnOn()
+     * @see #shutdown()
+     */
+    private final ReentrantLock isOnLock = new ReentrantLock();
+
+    /**
+     * A lock used for any changes to {@link #eventQueue}, {@link #command} or {@link #onComputerQueue}. This will be
+     * used on the main thread, so locks should be kept as brief as possible.
+     */
+    private final Object queueLock = new Object();
+
+    /**
+     * Determines if this executor is present within {@link ComputerThread}.
+     *
+     * @see #queueLock
+     * @see #enqueue()
+     * @see #afterWork()
+     */
+    volatile boolean onComputerQueue = false;
+
+    /**
+     * The amount of time this computer has used on a theoretical machine which shares work evenly amongst computers.
+     *
+     * @see ComputerThread
+     */
+    long virtualRuntime = 0;
+
+    /**
+     * The last time at which we updated {@link #virtualRuntime}.
+     *
+     * @see ComputerThread
+     */
+    long vRuntimeStart;
+
+    /**
+     * The command that {@link #work()} should execute on the computer thread.
+     *
+     * One sets the command with {@link #queueStart()} and {@link #queueStop(boolean, boolean)}. Neither of these will
+     * queue a new event if there is an existing one in the queue.
+     *
+     * Note, if command is not {@code null}, then some command is scheduled to be executed. Otherwise it is not
+     * currently in the queue (or is currently being executed).
+     */
+    private volatile StateCommand command;
+
+    /**
+     * The queue of events which should be executed when this computer is on.
+     *
+     * Note, this should be empty if this computer is off - it is cleared on shutdown and when turning on again.
+     */
+    private final Queue<Event> eventQueue = new ArrayDeque<>( 4 );
+
+    /**
+     * Whether we interrupted an event and so should resume it instead of executing another task.
+     *
+     * @see #work()
+     * @see #resumeMachine(String, Object[])
+     */
+    private boolean interruptedEvent = false;
+
+    /**
+     * Whether this executor has been closed, and will no longer accept any incoming commands or events.
+     *
+     * @see #queueStop(boolean, boolean)
+     */
+    private boolean closed;
+
+    private IWritableMount rootMount;
+
+    /**
+     * The thread the executor is running on. This is non-null when performing work. We use this to ensure we're only
+     * doing one bit of work at one time.
+     *
+     * @see ComputerThread
+     */
+    final AtomicReference<Thread> executingThread = new AtomicReference<>();
+
+    ComputerExecutor( Computer computer )
+    {
+        // Ensure the computer thread is running as required.
+        ComputerThread.start();
+
+        this.computer = computer;
+
+        Environment environment = computer.getEnvironment();
+
+        // Add all default APIs to the loaded list.
+        apis.add( new TermAPI( environment ) );
+        apis.add( new RedstoneAPI( environment ) );
+        apis.add( new FSAPI( environment ) );
+        apis.add( new PeripheralAPI( environment ) );
+        apis.add( new OSAPI( environment ) );
+        if( ComputerCraft.http_enable ) apis.add( new HTTPAPI( environment ) );
+
+        // Load in the externally registered APIs.
+        for( ILuaAPIFactory factory : ApiFactories.getAll() )
+        {
+            ComputerSystem system = new ComputerSystem( environment );
+            ILuaAPI api = factory.create( system );
+            if( api != null ) apis.add( new ApiWrapper( api, system ) );
+        }
+    }
+
+    boolean isOn()
+    {
+        return isOn;
+    }
+
+    FileSystem getFileSystem()
+    {
+        return fileSystem;
+    }
+
+    Computer getComputer()
+    {
+        return computer;
+    }
+
+    void addApi( ILuaAPI api )
+    {
+        apis.add( api );
+    }
+
+    /**
+     * Schedule this computer to be started if not already on.
+     */
+    void queueStart()
+    {
+        synchronized( queueLock )
+        {
+            // We should only schedule a start if we're not currently on and there's turn on.
+            if( closed || isOn || command != null ) return;
+
+            command = StateCommand.TURN_ON;
+            enqueue();
+        }
+    }
+
+    /**
+     * Schedule this computer to be stopped if not already on.
+     *
+     * @param reboot Reboot the computer after stopping
+     * @param close  Close the computer after stopping.
+     * @see #closed
+     */
+    void queueStop( boolean reboot, boolean close )
+    {
+        synchronized( queueLock )
+        {
+            if( closed ) return;
+            closed = close;
+
+            StateCommand newCommand = reboot ? StateCommand.REBOOT : StateCommand.SHUTDOWN;
+
+            // We should only schedule a stop if we're currently on and there's no shutdown pending.
+            if( !isOn || command != null )
+            {
+                // If we're closing, set the command just in case.
+                if( close ) command = newCommand;
+                return;
+            }
+
+            command = newCommand;
+            enqueue();
+        }
+    }
+
+    /**
+     * Abort this whole computer due to a timeout. This will immediately destroy the Lua machine,
+     * and then schedule a shutdown.
+     */
+    void abort()
+    {
+        ILuaMachine machine = this.machine;
+        if( machine != null ) machine.close();
+
+        synchronized( queueLock )
+        {
+            if( closed ) return;
+            command = StateCommand.ABORT;
+            if( isOn ) enqueue();
+        }
+    }
+
+    /**
+     * Queue an event if the computer is on
+     *
+     * @param event The event's name
+     * @param args  The event's arguments
+     */
+    void queueEvent( @Nonnull String event, @Nullable Object[] args )
+    {
+        // Events should be skipped if we're not on.
+        if( !isOn ) return;
+
+        synchronized( queueLock )
+        {
+            // And if we've got some command in the pipeline, then don't queue events - they'll
+            // probably be disposed of anyway.
+            // We also limit the number of events which can be queued.
+            if( closed || command != null || eventQueue.size() >= QUEUE_LIMIT ) return;
+
+            eventQueue.offer( new Event( event, args ) );
+            enqueue();
+        }
+    }
+
+    /**
+     * Add this executor to the {@link ComputerThread} if not already there.
+     */
+    private void enqueue()
+    {
+        synchronized( queueLock )
+        {
+            if( !onComputerQueue ) ComputerThread.queue( this );
+        }
+    }
+
+    /**
+     * Update the internals of the executor.
+     */
+    void tick()
+    {
+        if( isOn && isOnLock.tryLock() )
+        {
+            // This horrific structure means we don't try to update APIs while the state is being changed
+            // (and so they may be running startup/shutdown).
+            // We use tryLock here, as it has minimal delay, and it doesn't matter if we miss an advance at the
+            // beginning or end of a computer's lifetime.
+            try
+            {
+                if( isOn )
+                {
+                    // Advance our APIs.
+                    for( ILuaAPI api : apis ) api.update();
+                }
+            }
+            finally
+            {
+                isOnLock.unlock();
+            }
+        }
+    }
+
+    private IMount getRomMount()
+    {
+        if( romMount != null ) return romMount;
+
+        synchronized( romMountLock )
+        {
+            if( romMount != null ) return romMount;
+            return romMount = computer.getComputerEnvironment().createResourceMount( "computercraft", "lua/rom" );
+        }
+    }
+
+    IWritableMount getRootMount()
+    {
+        if( rootMount == null )
+        {
+            rootMount = computer.getComputerEnvironment().createSaveDirMount(
+                "computer/" + computer.assignID(),
+                computer.getComputerEnvironment().getComputerSpaceLimit()
+            );
+        }
+        return rootMount;
+    }
+
+    private FileSystem createFileSystem()
+    {
+        FileSystem filesystem = null;
+        try
+        {
+            filesystem = new FileSystem( "hdd", getRootMount() );
+
+            IMount romMount = getRomMount();
+            if( romMount == null )
+            {
+                displayFailure( "Cannot mount ROM", null );
+                return null;
+            }
+
+            filesystem.mount( "rom", "rom", romMount );
+            return filesystem;
+        }
+        catch( FileSystemException e )
+        {
+            if( filesystem != null ) filesystem.close();
+            ComputerCraft.log.error( "Cannot mount computer filesystem", e );
+
+            displayFailure( "Cannot mount computer system", null );
+            return null;
+        }
+    }
+
+    private ILuaMachine createLuaMachine()
+    {
+        // Load the bios resource
+        InputStream biosStream = null;
+        try
+        {
+            biosStream = computer.getComputerEnvironment().createResourceFile( "computercraft", "lua/bios.lua" );
+        }
+        catch( Exception ignored )
+        {
+        }
+
+        if( biosStream == null )
+        {
+            displayFailure( "Error loading bios.lua", null );
+            return null;
+        }
+
+        // Create the lua machine
+        ILuaMachine machine = new CobaltLuaMachine( computer, timeout );
+
+        // Add the APIs
+        for( ILuaAPI api : apis ) machine.addAPI( api );
+
+        // Start the machine running the bios resource
+        MachineResult result = machine.loadBios( biosStream );
+        IoUtil.closeQuietly( biosStream );
+
+        if( result.isError() )
+        {
+            machine.close();
+            displayFailure( "Error loading bios.lua", result.getMessage() );
+            return null;
+        }
+
+        return machine;
+    }
+
+    private void turnOn() throws InterruptedException
+    {
+        isOnLock.lockInterruptibly();
+        try
+        {
+            // Reset the terminal and event queue
+            computer.getTerminal().reset();
+            interruptedEvent = false;
+            synchronized( queueLock )
+            {
+                eventQueue.clear();
+            }
+
+            // Init filesystem
+            if( (fileSystem = createFileSystem()) == null )
+            {
+                shutdown();
+                return;
+            }
+
+            // Init APIs
+            for( ILuaAPI api : apis ) api.startup();
+
+            // Init lua
+            if( (machine = createLuaMachine()) == null )
+            {
+                shutdown();
+                return;
+            }
+
+            // Initialisation has finished, so let's mark ourselves as on.
+            isOn = true;
+            computer.markChanged();
+        }
+        finally
+        {
+            isOnLock.unlock();
+        }
+
+        // Now actually start the computer, now that everything is set up.
+        resumeMachine( null, null );
+    }
+
+    private void shutdown() throws InterruptedException
+    {
+        isOnLock.lockInterruptibly();
+        try
+        {
+            isOn = false;
+            interruptedEvent = false;
+            synchronized( queueLock )
+            {
+                eventQueue.clear();
+            }
+
+            // Shutdown Lua machine
+            if( machine != null )
+            {
+                machine.close();
+                machine = null;
+            }
+
+            // Shutdown our APIs
+            for( ILuaAPI api : apis ) api.shutdown();
+
+            // Unload filesystem
+            if( fileSystem != null )
+            {
+                fileSystem.close();
+                fileSystem = null;
+            }
+
+            computer.getEnvironment().resetOutput();
+            computer.markChanged();
+        }
+        finally
+        {
+            isOnLock.unlock();
+        }
+    }
+
+    /**
+     * Called before calling {@link #work()}, setting up any important state.
+     */
+    void beforeWork()
+    {
+        vRuntimeStart = System.nanoTime();
+        timeout.startTimer();
+    }
+
+    /**
+     * Called after executing {@link #work()}.
+     *
+     * @return If we have more work to do.
+     */
+    boolean afterWork()
+    {
+        if( interruptedEvent )
+        {
+            timeout.pauseTimer();
+        }
+        else
+        {
+            timeout.stopTimer();
+        }
+
+        Tracking.addTaskTiming( getComputer(), timeout.nanoCurrent() );
+
+        if( interruptedEvent ) return true;
+
+        synchronized( queueLock )
+        {
+            if( eventQueue.isEmpty() && command == null ) return onComputerQueue = false;
+            return true;
+        }
+    }
+
+    /**
+     * The main worker function, called by {@link ComputerThread}.
+     *
+     * This either executes a {@link StateCommand} or attempts to run an event
+     *
+     * @throws InterruptedException If various locks could not be acquired.
+     * @see #command
+     * @see #eventQueue
+     */
+    void work() throws InterruptedException
+    {
+        if( interruptedEvent )
+        {
+            interruptedEvent = false;
+            if( machine != null )
+            {
+                resumeMachine( null, null );
+                return;
+            }
+        }
+
+        StateCommand command;
+        Event event = null;
+        synchronized( queueLock )
+        {
+            command = this.command;
+            this.command = null;
+
+            // If we've no command, pull something from the event queue instead.
+            if( command == null )
+            {
+                if( !isOn )
+                {
+                    // We're not on and had no command, but we had work queued. This should never happen, so clear
+                    // the event queue just in case.
+                    eventQueue.clear();
+                    return;
+                }
+
+                event = eventQueue.poll();
+            }
+        }
+
+        if( command != null )
+        {
+            switch( command )
+            {
+                case TURN_ON:
+                    if( isOn ) return;
+                    turnOn();
+                    break;
+
+                case SHUTDOWN:
+
+                    if( !isOn ) return;
+                    computer.getTerminal().reset();
+                    shutdown();
+                    break;
+
+                case REBOOT:
+                    if( !isOn ) return;
+                    computer.getTerminal().reset();
+                    shutdown();
+
+                    computer.turnOn();
+                    break;
+
+                case ABORT:
+                    if( !isOn ) return;
+                    displayFailure( "Error running computer", TimeoutState.ABORT_MESSAGE );
+                    shutdown();
+                    break;
+            }
+        }
+        else if( event != null )
+        {
+            resumeMachine( event.name, event.args );
+        }
+    }
+
+    private void displayFailure( String message, String extra )
+    {
+        Terminal terminal = computer.getTerminal();
+        boolean colour = computer.getComputerEnvironment().isColour();
+        terminal.reset();
+
+        // Display our primary error message
+        if( colour ) terminal.setTextColour( 15 - Colour.Red.ordinal() );
+        terminal.write( message );
+
+        if( extra != null )
+        {
+            // Display any additional information. This generally comes from the Lua Machine, such as compilation or
+            // runtime errors.
+            terminal.setCursorPos( 0, terminal.getCursorY() + 1 );
+            terminal.write( extra );
+        }
+
+        // And display our generic "CC may be installed incorrectly" message.
+        terminal.setCursorPos( 0, terminal.getCursorY() + 1 );
+        if( colour ) terminal.setTextColour( 15 - Colour.White.ordinal() );
+        terminal.write( "ComputerCraft may be installed incorrectly" );
+    }
+
+    private void resumeMachine( String event, Object[] args ) throws InterruptedException
+    {
+        MachineResult result = machine.handleEvent( event, args );
+        interruptedEvent = result.isPause();
+        if( !result.isError() ) return;
+
+        displayFailure( "Error running computer", result.getMessage() );
+        shutdown();
+    }
+
+    private enum StateCommand
+    {
+        TURN_ON,
+        SHUTDOWN,
+        REBOOT,
+        ABORT,
+    }
+
+    private static final class Event
+    {
+        final String name;
+        final Object[] args;
+
+        private Event( String name, Object[] args )
+        {
+            this.name = name;
+            this.args = args;
+        }
+    }
+}