Prepare for 1.97.0 release

Yep, this is kinda gross. But also a nice refactor

.gitattributes

@@ -1,3 +1,15 @@
 # Ignore changes in generated files
 src/generated/resources/data/** linguist-generated
 src/test/server-files/structures linguist-generated
+
+* text=auto
+
+*.gradle eol=lf diff=java
+*.java   eol=lf diff=java
+*.kt     eol=lf diff=java
+*.lua    eol=lf
+*.md     eol=lf diff=markdown
+*.txt    eol=lf
+
+*.png binary
+*.jar binary

.github/ISSUE_TEMPLATE/bug_report.md

@@ -1,16 +0,0 @@
----
-name: Bug report
-about: Report some misbehaviour in the mod
-labels: bug
----
-
-<!--
-## Before reporting
- - 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
- - Logs: These will be located in the `logs/` directory of your Minecraft instance. Please upload them as a gist or directly into this editor.
- - 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/bug_report.yaml

@@ -0,0 +1,33 @@
+name: Bug report
+description: Report some misbehaviour in the mod
+labels: [ bug ]
+body:
+- type: dropdown
+  id: mc-version
+  attributes:
+    label: Minecraft Version
+    description: What version of Minecraft are you using?
+    options:
+      - 1.15.x
+      - 1.16.x
+  validations:
+    required: true
+- type: input
+  id: version
+  attributes:
+    label: Version
+    description: "What version of CC: Tweaked are you using?"
+    placeholder: "e.g. 1.96.0"
+  validations:
+    required: true
+- type: textarea
+  id: details
+  attributes:
+    label: Details
+    description: |
+      Description of the bug. Please include the following:
+      - Logs: These will be located in the `logs/` directory of your Minecraft
+        instance. Please upload them as a gist or directly into this editor.
+      - 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.

.gitpod.yml

@@ -0,0 +1,22 @@
+image:
+  file: config/gitpod/Dockerfile
+
+ports:
+  - port: 25565
+    onOpen: notify
+
+vscode:
+  extensions:
+    - eamodio.gitlens
+    - github.vscode-pull-request-github
+    - ms-azuretools.vscode-docker
+    - redhat.java
+    - richardwillis.vscode-gradle
+    - vscjava.vscode-java-debug
+    - vscode.github
+
+tasks:
+  - name: Setup pre-commit hool
+    init: pre-commit install --config config/pre-commit/config.yml --allow-missing-config
+  - name: Install npm packages
+    init: npm ci

CONTRIBUTING.md

@@ -19,6 +19,10 @@ process. When building on Windows, Use `gradlew.bat` instead of `./gradlew`.
  - **Clone the repository:** `git clone https://github.com/SquidDev-CC/CC-Tweaked.git && cd CC-Tweaked`
  - **Setup Forge:** `./gradlew build`
  - **Run Minecraft:** `./gradlew runClient` (or run the `GradleStart` class from your IDE).
+ - **Optionally:** For small PRs (especially those only touching Lua code), it may be easier to use GitPod, which
+   provides a pre-configured environment: [![Gitpod ready-to-code](https://img.shields.io/badge/Gitpod-ready--to--code-2b2b2b?logo=gitpod)](https://gitpod.io/#https://github.com/SquidDev-CC/CC-Tweaked/)
+
+   Do note you will need to download the mod after compiling to test.
 
 If you want to run CC:T in a normal Minecraft instance, run `./gradlew build` and copy the `.jar` from `build/libs`.
 These commands may take a few minutes to run the first time, as the environment is set up, but should be much faster

build.gradle

@@ -1,6 +1,5 @@
 buildscript {
     repositories {
-        jcenter()
         mavenCentral()
         maven {
             name = "forge"
@@ -9,8 +8,7 @@ buildscript {
     }
     dependencies {
         classpath 'com.google.code.gson:gson:2.8.1'
-        classpath 'net.minecraftforge.gradle:ForgeGradle:4.1.9'
-        classpath 'net.sf.proguard:proguard-gradle:6.1.0beta2'
+        classpath 'net.minecraftforge.gradle:ForgeGradle:5.0.6'
     }
 }
 
@@ -18,10 +16,11 @@ plugins {
     id "checkstyle"
     id "jacoco"
     id "maven-publish"
-    id "com.github.hierynomus.license" version "0.15.0"
+    id "com.github.hierynomus.license" version "0.16.1"
     id "com.matthewprenger.cursegradle" version "1.4.0"
     id "com.github.breadmoirai.github-release" version "2.2.12"
     id "org.jetbrains.kotlin.jvm" version "1.3.72"
+    id "com.modrinth.minotaur" version "1.2.1"
 }
 
 apply plugin: 'net.minecraftforge.gradle'
@@ -31,15 +30,30 @@ version = mod_version
 group = "org.squiddev"
 archivesBaseName = "cc-tweaked-${mc_version}"
 
+def javaVersion = JavaLanguageVersion.of(8)
 java {
     toolchain {
-        languageVersion = JavaLanguageVersion.of(8)
+        languageVersion = javaVersion
     }
 
     withSourcesJar()
     withJavadocJar()
 }
 
+// Tragically java.toolchain.languageVersion doesn't apply to ForgeGradle's
+// tasks, so we force all launchers to use the right Java version.
+tasks.withType(JavaCompile).configureEach {
+    javaCompiler = javaToolchains.compilerFor {
+        languageVersion = javaVersion
+    }
+}
+
+tasks.withType(JavaExec).configureEach {
+    javaLauncher = javaToolchains.launcherFor {
+        languageVersion = javaVersion
+    }
+}
+
 minecraft {
     runs {
         client {
@@ -183,59 +197,6 @@ jar {
     }
 }
 
-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 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"
-    libraryjars "${System.getProperty('java.home')}/lib/jce.jar"
-    doFirst {
-        sourceSets.main.compileClasspath
-            .filter { !it.name.contains("Cobalt") }
-            .each { libraryjars it }
-    }
-
-    // We want to avoid as much obfuscation as possible. We're only doing this to shrink code size.
-    dontobfuscate; dontoptimize; keepattributes; keepparameternames
-
-    // Proguard will remove directories by default, but that breaks JarMount.
-    keepdirectories 'data/computercraft/lua**'
-
-    // Preserve ComputerCraft classes - we only want to strip shadowed files.
-    keep 'class dan200.computercraft.** { *; }'
-
-    // LWJGL and Apache bundle Java 9 versions, which is great, but rather breaks Proguard
-    dontwarn 'module-info'
-    dontwarn 'org.apache.**,org.lwjgl.**'
-}
-
-task proguardMove(dependsOn: proguard) {
-    description "Replace the original jar with the minified version"
-    group "compact"
-
-    doLast {
-        Files.move(
-            file("${jar.archivePath.absolutePath.replace(".jar", "")}-min.jar").toPath(),
-            file(jar.archivePath).toPath(),
-            StandardCopyOption.REPLACE_EXISTING
-        )
-    }
-}
-
 processResources {
     inputs.property "version", mod_version
     inputs.property "mcversion", mc_version
@@ -253,6 +214,7 @@ processResources {
         e.printStackTrace()
     }
     inputs.property "commithash", hash
+    duplicatesStrategy = DuplicatesStrategy.INCLUDE
 
     from(sourceSets.main.resources.srcDirs) {
         include 'META-INF/mods.toml'
@@ -269,49 +231,10 @@ processResources {
     }
 }
 
-task compressJson(dependsOn: jar) {
-    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)
-    }
+sourcesJar {
+    duplicatesStrategy = DuplicatesStrategy.INCLUDE
 }
 
-assemble.dependsOn compressJson
-
 // Web tasks
 
 import org.apache.tools.ant.taskdefs.condition.Os
@@ -383,6 +306,10 @@ jacocoTestReport {
 
 check.dependsOn jacocoTestReport
 
+
+import com.hierynomus.gradle.license.tasks.LicenseCheck
+import com.hierynomus.gradle.license.tasks.LicenseFormat
+
 license {
     mapping("java", "SLASHSTAR_STYLE")
     strictCheck true
@@ -436,7 +363,7 @@ task setupServer(type: Copy) {
 tasks.register('testInGame', JavaExec.class).configure {
     it.group('test server')
     it.description("Runs tests on a temporary Minecraft server.")
-    it.dependsOn(setupServer, 'prepareRunTestServer')
+    it.dependsOn(setupServer, 'prepareRunTestServer', 'cleanTestInGame')
 
     // Copy from runTestServer. We do it in this slightly odd way as runTestServer
     // isn't created until the task is configured (which is no good for us).
@@ -490,31 +417,31 @@ task checkRelease {
     description "Verifies that everything is ready for a release"
 
     inputs.property "version", mod_version
-    inputs.file("src/main/resources/data/computercraft/lua/rom/help/changelog.txt")
-    inputs.file("src/main/resources/data/computercraft/lua/rom/help/whatsnew.txt")
+    inputs.file("src/main/resources/data/computercraft/lua/rom/help/changelog.md")
+    inputs.file("src/main/resources/data/computercraft/lua/rom/help/whatsnew.md")
 
     doLast {
         def ok = true
 
         // Check we're targetting the current version
-        def whatsnew = new File(projectDir, "src/main/resources/data/computercraft/lua/rom/help/whatsnew.txt").readLines()
+        def whatsnew = new File(projectDir, "src/main/resources/data/computercraft/lua/rom/help/whatsnew.md").readLines()
         if (whatsnew[0] != "New features in CC: Tweaked $mod_version") {
             ok = false
-            project.logger.error("Expected `whatsnew.txt' to target $mod_version.")
+            project.logger.error("Expected `whatsnew.md' 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")
+            project.logger.error("Must mention the changelog in whatsnew.md")
         } else {
             whatsnew = whatsnew.getAt(0 ..< idx)
         }
 
         // Check whatsnew and changelog match.
         def versionChangelog = "# " + whatsnew.join("\n")
-        def changelog = new File(projectDir, "src/main/resources/data/computercraft/lua/rom/help/changelog.txt").getText()
+        def changelog = new File(projectDir, "src/main/resources/data/computercraft/lua/rom/help/changelog.md").getText()
         if (!changelog.startsWith(versionChangelog)) {
             ok = false
             project.logger.error("whatsnew and changelog are not in sync")
@@ -538,6 +465,26 @@ curseforge {
     }
 }
 
+import com.modrinth.minotaur.TaskModrinthUpload
+tasks.register('publishModrinth', TaskModrinthUpload.class).configure {
+    dependsOn('assemble', 'reobfJar')
+    onlyIf {
+        project.hasProperty('modrinthApiKey')
+    }
+
+    token = project.hasProperty('curseForgeApiKey')
+    projectId = 'gu7yAYhd'
+    versionNumber = project.mod_version
+    uploadFile = jar
+    addGameVersion(project.mc_version)
+    addLoader('forge')
+}
+
+tasks.withType(GenerateModuleMetadata) {
+    // We can't generate metadata as that includes Forge as a dependency.
+    enabled = false
+}
+
 publishing {
     publications {
         maven(MavenPublication) {
@@ -563,6 +510,8 @@ publishing {
                         url = 'https://github.com/SquidDev-CC/CC-Tweaked/blob/mc-1.15.x/LICENSE'
                     }
                 }
+
+                withXml { asNode().remove(asNode().get("dependencies")) }
             }
         }
     }
@@ -605,10 +554,10 @@ githubRelease {
     prerelease false
 }
 
-def uploadTasks = ["publish", "curseforge", "githubRelease"]
+def uploadTasks = ["publish", "curseforge", "publishModrinth", "githubRelease"]
 uploadTasks.forEach { tasks.getByName(it).dependsOn checkRelease }
 
 task uploadAll(dependsOn: uploadTasks) {
     group "upload"
-    description "Uploads to all repositories (Maven, Curse, GitHub release)"
+    description "Uploads to all repositories (Maven, Curse, Modrinth, GitHub release)"
 }

config/checkstyle/suppressions.xml

@@ -7,9 +7,6 @@
     <suppress checks="StaticVariableName" files=".*[\\/]ComputerCraft.java" />
     <suppress checks="StaticVariableName" files=".*[\\/]ComputerCraftAPI.java" />
 
-    <!-- Do not check for missing package Javadoc. -->
-    <suppress checks="JavadocStyle" files=".*[\\/]package-info.java" />
-
     <!-- The commands API is documented in Lua. -->
     <suppress checks="SummaryJavadocCheck" files=".*[\\/]CommandAPI.java" />
 </suppressions>

config/gitpod/Dockerfile

@@ -0,0 +1,8 @@
+FROM gitpod/workspace-base
+
+USER gitpod
+
+RUN sudo apt-get -q update \
+ && sudo apt-get install -yq openjdk-8-jdk openjdk-16-jdk python3-pip npm \
+ && sudo pip3 install pre-commit \
+ && sudo update-java-alternatives --set java-1.8.0-openjdk-amd64

gradle.properties

@@ -1,5 +1,5 @@
 # Mod properties
-mod_version=1.96.0
+mod_version=1.97.0
 
 # Minecraft properties (update mods.toml when changing)
 mc_version=1.15.2

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.8.2-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.0-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

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

@@ -36,7 +36,6 @@ public final class ComputerCraft
     public static int maximumFilesOpen = 128;
     public static boolean disableLua51Features = false;
     public static String defaultComputerSettings = "";
-    public static boolean debugEnable = true;
     public static boolean logComputerErrors = true;
     public static boolean commandRequireCreative = true;
 

src/main/java/dan200/computercraft/api/client/TransformedModel.java

@@ -32,7 +32,7 @@ public final class TransformedModel
     public TransformedModel( @Nonnull IBakedModel model )
     {
         this.model = Objects.requireNonNull( model );
-        this.matrix = TransformationMatrix.identity();
+        matrix = TransformationMatrix.identity();
     }
 
     public static TransformedModel of( @Nonnull ModelResourceLocation location )

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

@@ -30,7 +30,7 @@ public class FileOperationException extends IOException
     public FileOperationException( @Nonnull String message )
     {
         super( Objects.requireNonNull( message, "message cannot be null" ) );
-        this.filename = null;
+        filename = null;
     }
 
     @Nullable

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

@@ -19,14 +19,14 @@ public class LuaException extends Exception
     public LuaException( @Nullable String message )
     {
         super( message );
-        this.hasLevel = false;
-        this.level = 1;
+        hasLevel = false;
+        level = 1;
     }
 
     public LuaException( @Nullable String message, int level )
     {
         super( message );
-        this.hasLevel = true;
+        hasLevel = true;
         this.level = level;
     }
 

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

@@ -30,14 +30,14 @@ public final class MethodResult
 
     private MethodResult( Object[] arguments, ILuaCallback callback )
     {
-        this.result = arguments;
+        result = arguments;
         this.callback = callback;
-        this.adjust = 0;
+        adjust = 0;
     }
 
     private MethodResult( Object[] arguments, ILuaCallback callback, int adjust )
     {
-        this.result = arguments;
+        result = arguments;
         this.callback = callback;
         this.adjust = adjust;
     }

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

@@ -0,0 +1,40 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.client;
+
+import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.shared.peripheral.monitor.ClientMonitor;
+import net.minecraftforge.api.distmarker.Dist;
+import net.minecraftforge.client.event.ClientPlayerNetworkEvent;
+import net.minecraftforge.event.world.WorldEvent;
+import net.minecraftforge.eventbus.api.SubscribeEvent;
+import net.minecraftforge.fml.common.Mod;
+
+@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Dist.CLIENT )
+public class ClientHooks
+{
+    @SubscribeEvent
+    public static void onWorldUnload( WorldEvent.Unload event )
+    {
+        if( event.getWorld().isClientSide() )
+        {
+            ClientMonitor.destroyAll();
+            SoundManager.reset();
+        }
+    }
+
+    @SubscribeEvent
+    public static void onLogIn( ClientPlayerNetworkEvent.LoggedInEvent event )
+    {
+        ComputerCraft.clientComputerRegistry.reset();
+    }
+
+    @SubscribeEvent
+    public static void onLogOut( ClientPlayerNetworkEvent.LoggedOutEvent event )
+    {
+        ComputerCraft.clientComputerRegistry.reset();
+    }
+}

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

@@ -6,31 +6,34 @@
 package dan200.computercraft.client;
 
 import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.client.gui.*;
+import dan200.computercraft.client.render.TileEntityMonitorRenderer;
+import dan200.computercraft.client.render.TileEntityTurtleRenderer;
 import dan200.computercraft.client.render.TurtleModelLoader;
+import dan200.computercraft.client.render.TurtlePlayerRenderer;
 import dan200.computercraft.shared.Registry;
 import dan200.computercraft.shared.common.IColouredItem;
+import dan200.computercraft.shared.computer.inventory.ContainerComputer;
+import dan200.computercraft.shared.computer.inventory.ContainerViewComputer;
 import dan200.computercraft.shared.media.items.ItemDisk;
 import dan200.computercraft.shared.media.items.ItemTreasureDisk;
+import dan200.computercraft.shared.pocket.inventory.ContainerPocketComputer;
 import dan200.computercraft.shared.pocket.items.ItemPocketComputer;
 import dan200.computercraft.shared.util.Colour;
-import net.minecraft.client.renderer.model.IBakedModel;
-import net.minecraft.client.renderer.model.IUnbakedModel;
+import net.minecraft.client.gui.ScreenManager;
+import net.minecraft.client.renderer.RenderType;
+import net.minecraft.client.renderer.RenderTypeLookup;
 import net.minecraft.client.renderer.model.ModelResourceLocation;
-import net.minecraft.inventory.container.PlayerContainer;
 import net.minecraft.util.ResourceLocation;
 import net.minecraftforge.api.distmarker.Dist;
 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.ModelLoader;
 import net.minecraftforge.client.model.ModelLoaderRegistry;
-import net.minecraftforge.client.model.SimpleModelTransform;
 import net.minecraftforge.eventbus.api.SubscribeEvent;
+import net.minecraftforge.fml.client.registry.RenderingRegistry;
 import net.minecraftforge.fml.common.Mod;
-
-import java.util.HashSet;
-import java.util.Map;
+import net.minecraftforge.fml.event.lifecycle.FMLClientSetupEvent;
 
 /**
  * Registers textures and models for items.
@@ -39,6 +42,7 @@ import java.util.Map;
 public final class ClientRegistry
 {
     private static final String[] EXTRA_MODELS = new String[] {
+        // Turtle upgrades
         "turtle_modem_normal_off_left",
         "turtle_modem_normal_on_left",
         "turtle_modem_normal_off_right",
@@ -54,56 +58,20 @@ public final class ClientRegistry
         "turtle_speaker_upgrade_left",
         "turtle_speaker_upgrade_right",
 
+        // Turtle block renderer
         "turtle_colour",
         "turtle_elf_overlay",
     };
 
-    private static final String[] EXTRA_TEXTURES = new String[] {
-        // TODO: Gather these automatically from the model. Sadly the model loader isn't available
-        //  when stitching textures.
-        "block/turtle_colour",
-        "block/turtle_elf_overlay",
-        "block/turtle_crafty_face",
-        "block/turtle_speaker_face",
-    };
-
     private ClientRegistry() {}
 
     @SubscribeEvent
     public static void registerModels( ModelRegistryEvent event )
     {
         ModelLoaderRegistry.registerLoader( new ResourceLocation( ComputerCraft.MOD_ID, "turtle" ), TurtleModelLoader.INSTANCE );
-    }
-
-    @SubscribeEvent
-    public static void onTextureStitchEvent( TextureStitchEvent.Pre event )
-    {
-        if( !event.getMap().location().equals( PlayerContainer.BLOCK_ATLAS ) ) return;
-
-        for( String extra : EXTRA_TEXTURES )
+        for( String model : EXTRA_MODELS )
         {
-            event.addSprite( new ResourceLocation( ComputerCraft.MOD_ID, extra ) );
-        }
-    }
-
-    @SubscribeEvent
-    public static void onModelBakeEvent( ModelBakeEvent event )
-    {
-        // Load all extra models
-        ModelLoader loader = event.getModelLoader();
-        Map<ResourceLocation, IBakedModel> registry = event.getModelRegistry();
-
-        for( String modelName : EXTRA_MODELS )
-        {
-            ResourceLocation location = new ResourceLocation( ComputerCraft.MOD_ID, "item/" + modelName );
-            IUnbakedModel model = loader.getModel( location );
-            model.getMaterials( loader::getModel, new HashSet<>() );
-
-            IBakedModel baked = model.bake( loader, ModelLoader.defaultTextureGetter(), SimpleModelTransform.IDENTITY, location );
-            if( baked != null )
-            {
-                registry.put( new ModelResourceLocation( new ResourceLocation( ComputerCraft.MOD_ID, modelName ), "inventory" ), baked );
-            }
+            ModelLoader.addSpecialModel( new ModelResourceLocation( new ResourceLocation( ComputerCraft.MOD_ID, model ), "inventory" ) );
         }
     }
 
@@ -148,4 +116,41 @@ public final class ClientRegistry
             Registry.ModBlocks.TURTLE_NORMAL.get(), Registry.ModBlocks.TURTLE_ADVANCED.get()
         );
     }
+
+    @SubscribeEvent
+    public static void setupClient( FMLClientSetupEvent event )
+    {
+        registerContainers();
+
+        // While turtles themselves are not transparent, their upgrades may be.
+        RenderTypeLookup.setRenderLayer( Registry.ModBlocks.TURTLE_NORMAL.get(), RenderType.translucent() );
+        RenderTypeLookup.setRenderLayer( Registry.ModBlocks.TURTLE_ADVANCED.get(), RenderType.translucent() );
+
+        // Monitors' textures have transparent fronts and so count as cutouts.
+        RenderTypeLookup.setRenderLayer( Registry.ModBlocks.MONITOR_NORMAL.get(), RenderType.cutout() );
+        RenderTypeLookup.setRenderLayer( Registry.ModBlocks.MONITOR_ADVANCED.get(), RenderType.cutout() );
+
+        // Setup TESRs
+        net.minecraftforge.fml.client.registry.ClientRegistry.bindTileEntityRenderer( Registry.ModTiles.MONITOR_NORMAL.get(), TileEntityMonitorRenderer::new );
+        net.minecraftforge.fml.client.registry.ClientRegistry.bindTileEntityRenderer( Registry.ModTiles.MONITOR_ADVANCED.get(), TileEntityMonitorRenderer::new );
+        net.minecraftforge.fml.client.registry.ClientRegistry.bindTileEntityRenderer( Registry.ModTiles.TURTLE_NORMAL.get(), TileEntityTurtleRenderer::new );
+        net.minecraftforge.fml.client.registry.ClientRegistry.bindTileEntityRenderer( Registry.ModTiles.TURTLE_ADVANCED.get(), TileEntityTurtleRenderer::new );
+
+        RenderingRegistry.registerEntityRenderingHandler( Registry.ModEntities.TURTLE_PLAYER.get(), TurtlePlayerRenderer::new );
+    }
+
+    private static void registerContainers()
+    {
+        // My IDE doesn't think so, but we do actually need these generics.
+
+        ScreenManager.<ContainerComputer, GuiComputer<ContainerComputer>>register( Registry.ModContainers.COMPUTER.get(), GuiComputer::create );
+        ScreenManager.<ContainerPocketComputer, GuiComputer<ContainerPocketComputer>>register( Registry.ModContainers.POCKET_COMPUTER.get(), GuiComputer::createPocket );
+        ScreenManager.register( Registry.ModContainers.TURTLE.get(), GuiTurtle::new );
+
+        ScreenManager.register( Registry.ModContainers.PRINTER.get(), GuiPrinter::new );
+        ScreenManager.register( Registry.ModContainers.DISK_DRIVE.get(), GuiDiskDrive::new );
+        ScreenManager.register( Registry.ModContainers.PRINTOUT.get(), GuiPrintout::new );
+
+        ScreenManager.<ContainerViewComputer, GuiComputer<ContainerViewComputer>>register( Registry.ModContainers.VIEW_COMPUTER.get(), GuiComputer::createView );
+    }
 }

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

@@ -0,0 +1,84 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.client;
+
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.audio.ISound;
+import net.minecraft.client.audio.ITickableSound;
+import net.minecraft.client.audio.LocatableSound;
+import net.minecraft.client.audio.SoundHandler;
+import net.minecraft.util.SoundCategory;
+import net.minecraft.util.SoundEvent;
+import net.minecraft.util.math.Vec3d;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.UUID;
+
+public class SoundManager
+{
+    private static final Map<UUID, MoveableSound> sounds = new HashMap<>();
+
+    public static void playSound( UUID source, Vec3d position, SoundEvent event, float volume, float pitch )
+    {
+        SoundHandler soundManager = Minecraft.getInstance().getSoundManager();
+
+        MoveableSound oldSound = sounds.get( source );
+        if( oldSound != null ) soundManager.stop( oldSound );
+
+        MoveableSound newSound = new MoveableSound( event, position, volume, pitch );
+        sounds.put( source, newSound );
+        soundManager.play( newSound );
+    }
+
+    public static void stopSound( UUID source )
+    {
+        ISound sound = sounds.remove( source );
+        if( sound == null ) return;
+
+        Minecraft.getInstance().getSoundManager().stop( sound );
+    }
+
+    public static void moveSound( UUID source, Vec3d position )
+    {
+        MoveableSound sound = sounds.get( source );
+        if( sound != null ) sound.setPosition( position );
+    }
+
+    public static void reset()
+    {
+        sounds.clear();
+    }
+
+    private static class MoveableSound extends LocatableSound implements ITickableSound
+    {
+        protected MoveableSound( SoundEvent sound, Vec3d position, float volume, float pitch )
+        {
+            super( sound, SoundCategory.RECORDS );
+            setPosition( position );
+            this.volume = volume;
+            this.pitch = pitch;
+        }
+
+        void setPosition( Vec3d position )
+        {
+            x = (float) position.x();
+            y = (float) position.y();
+            z = (float) position.z();
+        }
+
+        @Override
+        public boolean isStopped()
+        {
+            return false;
+        }
+
+        @Override
+        public void tick()
+        {
+        }
+    }
+}

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

@@ -0,0 +1,94 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.client.gui;
+
+import dan200.computercraft.client.gui.widgets.ComputerSidebar;
+import dan200.computercraft.client.gui.widgets.WidgetTerminal;
+import dan200.computercraft.shared.computer.core.ClientComputer;
+import dan200.computercraft.shared.computer.core.ComputerFamily;
+import dan200.computercraft.shared.computer.inventory.ContainerComputerBase;
+import net.minecraft.client.gui.screen.inventory.ContainerScreen;
+import net.minecraft.client.gui.widget.Widget;
+import net.minecraft.entity.player.PlayerInventory;
+import net.minecraft.util.text.ITextComponent;
+import org.lwjgl.glfw.GLFW;
+
+public abstract class ComputerScreenBase<T extends ContainerComputerBase> extends ContainerScreen<T>
+{
+    protected WidgetTerminal terminal;
+    protected final ClientComputer computer;
+    protected final ComputerFamily family;
+
+    protected final int sidebarYOffset;
+
+    public ComputerScreenBase( T container, PlayerInventory player, ITextComponent title, int sidebarYOffset )
+    {
+        super( container, player, title );
+        computer = (ClientComputer) container.getComputer();
+        family = container.getFamily();
+        this.sidebarYOffset = sidebarYOffset;
+    }
+
+    protected abstract WidgetTerminal createTerminal();
+
+    @Override
+    protected final void init()
+    {
+        super.init();
+        minecraft.keyboardHandler.setSendRepeatsToGui( true );
+
+        terminal = addButton( createTerminal() );
+        ComputerSidebar.addButtons( this, computer, this::addButton, leftPos, topPos + sidebarYOffset );
+        setFocused( terminal );
+    }
+
+    @Override
+    public final void removed()
+    {
+        super.removed();
+        minecraft.keyboardHandler.setSendRepeatsToGui( false );
+    }
+
+    @Override
+    public final void tick()
+    {
+        super.tick();
+        terminal.update();
+    }
+
+    @Override
+    public final boolean keyPressed( int key, int scancode, int modifiers )
+    {
+        // Forward the tab key to the terminal, rather than moving between controls.
+        if( key == GLFW.GLFW_KEY_TAB && getFocused() != null && getFocused() == terminal )
+        {
+            return getFocused().keyPressed( key, scancode, modifiers );
+        }
+
+        return super.keyPressed( key, scancode, modifiers );
+    }
+
+
+    @Override
+    public final void render( int mouseX, int mouseY, float partialTicks )
+    {
+        renderBackground();
+        super.render( mouseX, mouseY, partialTicks );
+        renderTooltip( mouseX, mouseY );
+
+        for( Widget widget : buttons )
+        {
+            if( widget.isHovered() ) widget.renderToolTip( mouseX, mouseY );
+        }
+    }
+
+    @Override
+    public final boolean mouseDragged( double x, double y, int button, double deltaX, double deltaY )
+    {
+        return (getFocused() != null && getFocused().mouseDragged( x, y, button, deltaX, deltaY ))
+            || super.mouseDragged( x, y, button, deltaX, deltaY );
+    }
+}

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

@@ -7,43 +7,33 @@ package dan200.computercraft.client.gui;
 
 import com.mojang.blaze3d.systems.RenderSystem;
 import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.client.gui.widgets.ComputerSidebar;
 import dan200.computercraft.client.gui.widgets.WidgetTerminal;
-import dan200.computercraft.client.gui.widgets.WidgetWrapper;
 import dan200.computercraft.client.render.ComputerBorderRenderer;
-import dan200.computercraft.shared.computer.core.ClientComputer;
-import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.computer.inventory.ContainerComputer;
 import dan200.computercraft.shared.computer.inventory.ContainerComputerBase;
 import dan200.computercraft.shared.computer.inventory.ContainerViewComputer;
 import dan200.computercraft.shared.pocket.inventory.ContainerPocketComputer;
-import net.minecraft.client.gui.screen.inventory.ContainerScreen;
 import net.minecraft.entity.player.PlayerInventory;
 import net.minecraft.util.text.ITextComponent;
-import org.lwjgl.glfw.GLFW;
 
 import static dan200.computercraft.client.render.ComputerBorderRenderer.BORDER;
-import static dan200.computercraft.client.render.ComputerBorderRenderer.MARGIN;
 
-public final class GuiComputer<T extends ContainerComputerBase> extends ContainerScreen<T>
+public final class GuiComputer<T extends ContainerComputerBase> extends ComputerScreenBase<T>
 {
-    private final ComputerFamily family;
-    private final ClientComputer computer;
     private final int termWidth;
     private final int termHeight;
 
-    private WidgetTerminal terminal;
-    private WidgetWrapper terminalWrapper;
-
     private GuiComputer(
         T container, PlayerInventory player, ITextComponent title, int termWidth, int termHeight
     )
     {
-        super( container, player, title );
-        family = container.getFamily();
-        computer = (ClientComputer) container.getComputer();
+        super( container, player, title, BORDER );
         this.termWidth = termWidth;
         this.termHeight = termHeight;
-        terminal = null;
+
+        imageWidth = WidgetTerminal.getWidth( termWidth ) + BORDER * 2 + ComputerSidebar.WIDTH;
+        imageHeight = WidgetTerminal.getHeight( termHeight ) + BORDER * 2;
     }
 
     public static GuiComputer<ContainerComputer> create( ContainerComputer container, PlayerInventory inventory, ITextComponent component )
@@ -70,82 +60,21 @@ public final class GuiComputer<T extends ContainerComputerBase> extends Containe
         );
     }
 
-
     @Override
-    protected void init()
+    protected WidgetTerminal createTerminal()
     {
-        minecraft.keyboardHandler.setSendRepeatsToGui( true );
-
-        int termPxWidth = termWidth * FixedWidthFontRenderer.FONT_WIDTH;
-        int termPxHeight = termHeight * FixedWidthFontRenderer.FONT_HEIGHT;
-
-        imageWidth = termPxWidth + MARGIN * 2 + BORDER * 2;
-        imageHeight = termPxHeight + MARGIN * 2 + BORDER * 2;
-
-        super.init();
-
-        terminal = new WidgetTerminal( minecraft, () -> computer, termWidth, termHeight, MARGIN, MARGIN, MARGIN, MARGIN );
-        terminalWrapper = new WidgetWrapper( terminal, MARGIN + BORDER + leftPos, MARGIN + BORDER + topPos, termPxWidth, termPxHeight );
-
-        children.add( terminalWrapper );
-        setFocused( terminalWrapper );
-    }
-
-    @Override
-    public void removed()
-    {
-        super.removed();
-        children.remove( terminal );
-        terminal = null;
-        minecraft.keyboardHandler.setSendRepeatsToGui( false );
-    }
-
-    @Override
-    public void tick()
-    {
-        super.tick();
-        terminal.update();
-    }
-
-    @Override
-    public boolean keyPressed( int key, int scancode, int modifiers )
-    {
-        // Forward the tab key to the terminal, rather than moving between controls.
-        if( key == GLFW.GLFW_KEY_TAB && getFocused() != null && getFocused() == terminalWrapper )
-        {
-            return getFocused().keyPressed( key, scancode, modifiers );
-        }
-
-        return super.keyPressed( key, scancode, modifiers );
+        return new WidgetTerminal( computer,
+            leftPos + ComputerSidebar.WIDTH + BORDER, topPos + BORDER, termWidth, termHeight
+        );
     }
 
     @Override
     public void renderBg( float partialTicks, int mouseX, int mouseY )
     {
-        // Draw terminal
-        terminal.draw( terminalWrapper.getX(), terminalWrapper.getY() );
-
         // Draw a border around the terminal
         RenderSystem.color4f( 1, 1, 1, 1 );
         minecraft.getTextureManager().bind( ComputerBorderRenderer.getTexture( family ) );
-        ComputerBorderRenderer.render(
-            terminalWrapper.getX() - MARGIN, terminalWrapper.getY() - MARGIN, getBlitOffset(),
-            terminalWrapper.getWidth() + MARGIN * 2, terminalWrapper.getHeight() + MARGIN * 2
-        );
-    }
-
-    @Override
-    public void render( int mouseX, int mouseY, float partialTicks )
-    {
-        renderBackground();
-        super.render( mouseX, mouseY, partialTicks );
-        renderTooltip( mouseX, mouseY );
-    }
-
-    @Override
-    public boolean mouseDragged( double x, double y, int button, double deltaX, double deltaY )
-    {
-        return (getFocused() != null && getFocused().mouseDragged( x, y, button, deltaX, deltaY ))
-            || super.mouseDragged( x, y, button, deltaX, deltaY );
+        ComputerBorderRenderer.render( terminal.x, terminal.y, getBlitOffset(), terminal.getWidth(), terminal.getHeight() );
+        ComputerSidebar.renderBackground( leftPos, topPos + sidebarYOffset );
     }
 }

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

@@ -7,132 +7,67 @@ package dan200.computercraft.client.gui;
 
 import com.mojang.blaze3d.systems.RenderSystem;
 import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.client.gui.widgets.ComputerSidebar;
 import dan200.computercraft.client.gui.widgets.WidgetTerminal;
-import dan200.computercraft.client.gui.widgets.WidgetWrapper;
-import dan200.computercraft.shared.computer.core.ClientComputer;
+import dan200.computercraft.client.render.ComputerBorderRenderer;
 import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.turtle.inventory.ContainerTurtle;
-import net.minecraft.client.gui.screen.inventory.ContainerScreen;
 import net.minecraft.entity.player.PlayerInventory;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.util.text.ITextComponent;
-import org.lwjgl.glfw.GLFW;
 
-public class GuiTurtle extends ContainerScreen<ContainerTurtle>
+import static dan200.computercraft.shared.turtle.inventory.ContainerTurtle.*;
+
+public class GuiTurtle extends ComputerScreenBase<ContainerTurtle>
 {
     private static final ResourceLocation BACKGROUND_NORMAL = new ResourceLocation( ComputerCraft.MOD_ID, "textures/gui/turtle_normal.png" );
     private static final ResourceLocation BACKGROUND_ADVANCED = new ResourceLocation( ComputerCraft.MOD_ID, "textures/gui/turtle_advanced.png" );
 
-    private final ContainerTurtle container;
+    private static final int TEX_WIDTH = 254;
+    private static final int TEX_HEIGHT = 217;
 
     private final ComputerFamily family;
-    private final ClientComputer computer;
-
-    private WidgetTerminal terminal;
-    private WidgetWrapper terminalWrapper;
 
     public GuiTurtle( ContainerTurtle container, PlayerInventory player, ITextComponent title )
     {
-        super( container, player, title );
-
-        this.container = container;
+        super( container, player, title, BORDER );
         family = container.getFamily();
-        computer = (ClientComputer) container.getComputer();
 
-        imageWidth = 254;
-        imageHeight = 217;
+        imageWidth = TEX_WIDTH + ComputerSidebar.WIDTH;
+        imageHeight = TEX_HEIGHT;
     }
 
     @Override
-    protected void init()
+    protected WidgetTerminal createTerminal()
     {
-        super.init();
-        minecraft.keyboardHandler.setSendRepeatsToGui( true );
-
-        int termPxWidth = ComputerCraft.turtleTermWidth * FixedWidthFontRenderer.FONT_WIDTH;
-        int termPxHeight = ComputerCraft.turtleTermHeight * FixedWidthFontRenderer.FONT_HEIGHT;
-
-        terminal = new WidgetTerminal(
-            minecraft, () -> computer,
-            ComputerCraft.turtleTermWidth,
-            ComputerCraft.turtleTermHeight,
-            2, 2, 2, 2
+        return new WidgetTerminal(
+            computer, leftPos + BORDER + ComputerSidebar.WIDTH, topPos + BORDER,
+            ComputerCraft.turtleTermWidth, ComputerCraft.turtleTermHeight
         );
-        terminalWrapper = new WidgetWrapper( terminal, 2 + 8 + leftPos, 2 + 8 + topPos, termPxWidth, termPxHeight );
-
-        children.add( terminalWrapper );
-        setFocused( terminalWrapper );
-    }
-
-    @Override
-    public void removed()
-    {
-        super.removed();
-        children.remove( terminal );
-        terminal = null;
-        minecraft.keyboardHandler.setSendRepeatsToGui( false );
-    }
-
-    @Override
-    public void tick()
-    {
-        super.tick();
-        terminal.update();
-    }
-
-    @Override
-    public boolean keyPressed( int key, int scancode, int modifiers )
-    {
-        // Forward the tab key to the terminal, rather than moving between controls.
-        if( key == GLFW.GLFW_KEY_TAB && getFocused() != null && getFocused() == terminalWrapper )
-        {
-            return getFocused().keyPressed( key, scancode, modifiers );
-        }
-
-        return super.keyPressed( key, scancode, modifiers );
-    }
-
-    private void drawSelectionSlot( boolean advanced )
-    {
-        // Draw selection slot
-        int slot = container.getSelectedSlot();
-        if( slot >= 0 )
-        {
-            RenderSystem.color4f( 1.0F, 1.0F, 1.0F, 1.0F );
-            int slotX = slot % 4;
-            int slotY = slot / 4;
-            minecraft.getTextureManager().bind( advanced ? BACKGROUND_ADVANCED : BACKGROUND_NORMAL );
-            blit( leftPos + ContainerTurtle.TURTLE_START_X - 2 + slotX * 18, topPos + ContainerTurtle.PLAYER_START_Y - 2 + slotY * 18, 0, 217, 24, 24 );
-        }
     }
 
     @Override
     protected void renderBg( float partialTicks, int mouseX, int mouseY )
     {
-        // Draw term
         boolean advanced = family == ComputerFamily.ADVANCED;
-        terminal.draw( terminalWrapper.getX(), terminalWrapper.getY() );
 
-        // Draw border/inventory
         RenderSystem.color4f( 1.0F, 1.0F, 1.0F, 1.0F );
         minecraft.getTextureManager().bind( advanced ? BACKGROUND_ADVANCED : BACKGROUND_NORMAL );
-        blit( leftPos, topPos, 0, 0, imageWidth, imageHeight );
+        blit( leftPos + ComputerSidebar.WIDTH, topPos, 0, 0, TEX_WIDTH, TEX_HEIGHT );
 
-        drawSelectionSlot( advanced );
-    }
+        minecraft.getTextureManager().bind( advanced ? ComputerBorderRenderer.BACKGROUND_ADVANCED : ComputerBorderRenderer.BACKGROUND_NORMAL );
+        ComputerSidebar.renderBackground( leftPos, topPos + sidebarYOffset );
 
-    @Override
-    public void render( int mouseX, int mouseY, float partialTicks )
-    {
-        renderBackground();
-        super.render( mouseX, mouseY, partialTicks );
-        renderTooltip( mouseX, mouseY );
-    }
-
-    @Override
-    public boolean mouseDragged( double x, double y, int button, double deltaX, double deltaY )
-    {
-        return (getFocused() != null && getFocused().mouseDragged( x, y, button, deltaX, deltaY ))
-            || super.mouseDragged( x, y, button, deltaX, deltaY );
+        int slot = getMenu().getSelectedSlot();
+        if( slot >= 0 )
+        {
+            RenderSystem.color4f( 1.0F, 1.0F, 1.0F, 1.0F );
+            int slotX = slot % 4;
+            int slotY = slot / 4;
+            blit(
+                leftPos + TURTLE_START_X - 2 + slotX * 18, topPos + PLAYER_START_Y - 2 + slotY * 18,
+                0, 217, 24, 24
+            );
+        }
     }
 }

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

@@ -0,0 +1,105 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.client.gui.widgets;
+
+import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.client.render.ComputerBorderRenderer;
+import dan200.computercraft.shared.computer.core.ClientComputer;
+import net.minecraft.client.gui.screen.Screen;
+import net.minecraft.client.gui.widget.Widget;
+import net.minecraft.client.resources.I18n;
+import net.minecraft.util.ResourceLocation;
+import net.minecraft.util.text.TextFormatting;
+
+import java.util.Arrays;
+import java.util.function.Consumer;
+
+/**
+ * Registers buttons to interact with a computer.
+ */
+public final class ComputerSidebar
+{
+    private static final ResourceLocation TEXTURE = new ResourceLocation( ComputerCraft.MOD_ID, "textures/gui/buttons.png" );
+
+    private static final int TEX_SIZE = 64;
+
+    private static final int ICON_WIDTH = 12;
+    private static final int ICON_HEIGHT = 12;
+    private static final int ICON_MARGIN = 2;
+
+    private static final int ICON_TEX_Y_DIFF = 14;
+
+    private static final int CORNERS_BORDER = 3;
+    private static final int FULL_BORDER = CORNERS_BORDER + ICON_MARGIN;
+
+    private static final int BUTTONS = 2;
+    private static final int HEIGHT = (ICON_HEIGHT + ICON_MARGIN * 2) * BUTTONS + CORNERS_BORDER * 2;
+    public static final int WIDTH = 17;
+
+    private ComputerSidebar()
+    {
+    }
+
+    public static void addButtons( Screen screen, ClientComputer computer, Consumer<Widget> add, int x, int y )
+    {
+        x += CORNERS_BORDER + 1;
+        y += CORNERS_BORDER + ICON_MARGIN;
+
+        add.accept( new DynamicImageButton(
+            screen, x, y, ICON_WIDTH, ICON_HEIGHT, () -> computer.isOn() ? 15 : 1, 1, ICON_TEX_Y_DIFF,
+            TEXTURE, TEX_SIZE, TEX_SIZE, b -> toggleComputer( computer ),
+            () -> computer.isOn() ? Arrays.asList(
+                I18n.get( "gui.computercraft.tooltip.turn_off" ),
+                TextFormatting.GRAY + I18n.get( "gui.computercraft.tooltip.turn_off.key" )
+            ) : Arrays.asList(
+                I18n.get( "gui.computercraft.tooltip.turn_on" ),
+                TextFormatting.GRAY + I18n.get( "gui.computercraft.tooltip.turn_off.key" )
+            )
+        ) );
+
+        y += ICON_HEIGHT + ICON_MARGIN * 2;
+
+        add.accept( new DynamicImageButton(
+            screen, x, y, ICON_WIDTH, ICON_HEIGHT, 29, 1, ICON_TEX_Y_DIFF,
+            TEXTURE, TEX_SIZE, TEX_SIZE, b -> computer.queueEvent( "terminate" ),
+            Arrays.asList(
+                I18n.get( "gui.computercraft.tooltip.terminate" ),
+                TextFormatting.GRAY + I18n.get( "gui.computercraft.tooltip.terminate.key" )
+            )
+        ) );
+    }
+
+    public static void renderBackground( int x, int y )
+    {
+        Screen.blit(
+            x, y, 0, 102, WIDTH, FULL_BORDER,
+            ComputerBorderRenderer.TEX_SIZE, ComputerBorderRenderer.TEX_SIZE
+        );
+
+        Screen.blit(
+            x, y + FULL_BORDER, WIDTH, HEIGHT - FULL_BORDER * 2,
+            0, 107, WIDTH, 4,
+            ComputerBorderRenderer.TEX_SIZE, ComputerBorderRenderer.TEX_SIZE
+        );
+
+        Screen.blit(
+            x, y + HEIGHT - FULL_BORDER, 0, 111, WIDTH, FULL_BORDER,
+            ComputerBorderRenderer.TEX_SIZE, ComputerBorderRenderer.TEX_SIZE
+        );
+    }
+
+    private static void toggleComputer( ClientComputer computer )
+    {
+        if( computer.isOn() )
+        {
+            computer.shutdown();
+        }
+        else
+        {
+            computer.turnOn();
+        }
+    }
+}

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

@@ -0,0 +1,93 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.client.gui.widgets;
+
+import com.mojang.blaze3d.systems.RenderSystem;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.gui.screen.Screen;
+import net.minecraft.client.gui.widget.button.Button;
+import net.minecraft.util.ResourceLocation;
+import net.minecraftforge.common.util.NonNullSupplier;
+
+import javax.annotation.Nonnull;
+import java.util.List;
+import java.util.function.IntSupplier;
+
+/**
+ * Version of {@link net.minecraft.client.gui.widget.button.ImageButton} which allows changing some properties
+ * dynamically.
+ */
+public class DynamicImageButton extends Button
+{
+    private final Screen screen;
+    private final ResourceLocation texture;
+    private final IntSupplier xTexStart;
+    private final int yTexStart;
+    private final int yDiffTex;
+    private final int textureWidth;
+    private final int textureHeight;
+    private final NonNullSupplier<List<String>> tooltip;
+
+    public DynamicImageButton(
+        Screen screen, int x, int y, int width, int height, int xTexStart, int yTexStart, int yDiffTex,
+        ResourceLocation texture, int textureWidth, int textureHeight,
+        IPressable onPress, List<String> tooltip
+    )
+    {
+        this(
+            screen, x, y, width, height, () -> xTexStart, yTexStart, yDiffTex,
+            texture, textureWidth, textureHeight,
+            onPress, () -> tooltip
+        );
+    }
+
+
+    public DynamicImageButton(
+        Screen screen, int x, int y, int width, int height, IntSupplier xTexStart, int yTexStart, int yDiffTex,
+        ResourceLocation texture, int textureWidth, int textureHeight,
+        IPressable onPress, NonNullSupplier<List<String>> tooltip
+    )
+    {
+        super( x, y, width, height, "", onPress );
+        this.screen = screen;
+        this.textureWidth = textureWidth;
+        this.textureHeight = textureHeight;
+        this.xTexStart = xTexStart;
+        this.yTexStart = yTexStart;
+        this.yDiffTex = yDiffTex;
+        this.texture = texture;
+        this.tooltip = tooltip;
+    }
+
+    @Override
+    public void renderButton( int mouseX, int mouseY, float partialTicks )
+    {
+        Minecraft minecraft = Minecraft.getInstance();
+        minecraft.getTextureManager().bind( texture );
+        RenderSystem.disableDepthTest();
+
+        int yTex = yTexStart;
+        if( isHovered() ) yTex += yDiffTex;
+
+        blit( x, y, xTexStart.getAsInt(), yTex, width, height, textureWidth, textureHeight );
+        RenderSystem.enableDepthTest();
+    }
+
+    @Nonnull
+    @Override
+    public String getMessage()
+    {
+        List<String> tooltip = this.tooltip.get();
+        return tooltip.isEmpty() ? "" : tooltip.get( 0 );
+    }
+
+    @Override
+    public void renderToolTip( int mouseX, int mouseY )
+    {
+        List<String> tooltip = this.tooltip.get();
+        if( !tooltip.isEmpty() ) screen.renderTooltip( tooltip, mouseX, mouseY );
+    }
+}

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

@@ -8,29 +8,29 @@ package dan200.computercraft.client.gui.widgets;
 import dan200.computercraft.client.gui.FixedWidthFontRenderer;
 import dan200.computercraft.core.terminal.Terminal;
 import dan200.computercraft.shared.computer.core.ClientComputer;
-import dan200.computercraft.shared.computer.core.IComputer;
 import net.minecraft.client.Minecraft;
-import net.minecraft.client.gui.IGuiEventListener;
+import net.minecraft.client.gui.widget.Widget;
 import net.minecraft.util.SharedConstants;
 import org.lwjgl.glfw.GLFW;
 
+import javax.annotation.Nonnull;
 import java.util.BitSet;
-import java.util.function.Supplier;
 
 import static dan200.computercraft.client.gui.FixedWidthFontRenderer.FONT_HEIGHT;
 import static dan200.computercraft.client.gui.FixedWidthFontRenderer.FONT_WIDTH;
+import static dan200.computercraft.client.render.ComputerBorderRenderer.MARGIN;
 
-public class WidgetTerminal implements IGuiEventListener
+public class WidgetTerminal extends Widget
 {
     private static final float TERMINATE_TIME = 0.5f;
 
-    private final Minecraft client;
+    private final ClientComputer computer;
 
-    private boolean focused;
-
-    private final Supplier<ClientComputer> computer;
-    private final int termWidth;
-    private final int termHeight;
+    // The positions of the actual terminal
+    private final int innerX;
+    private final int innerY;
+    private final int innerWidth;
+    private final int innerHeight;
 
     private float terminateTimer = -1;
     private float rebootTimer = -1;
@@ -40,23 +40,18 @@ public class WidgetTerminal implements IGuiEventListener
     private int lastMouseX = -1;
     private int lastMouseY = -1;
 
-    private final int leftMargin;
-    private final int rightMargin;
-    private final int topMargin;
-    private final int bottomMargin;
-
     private final BitSet keysDown = new BitSet( 256 );
 
-    public WidgetTerminal( Minecraft client, Supplier<ClientComputer> computer, int termWidth, int termHeight, int leftMargin, int rightMargin, int topMargin, int bottomMargin )
+    public WidgetTerminal( @Nonnull ClientComputer computer, int x, int y, int termWidth, int termHeight )
     {
-        this.client = client;
+        super( x, y, termWidth * FONT_WIDTH + MARGIN * 2, termHeight * FONT_HEIGHT + MARGIN * 2, "" );
+
         this.computer = computer;
-        this.termWidth = termWidth;
-        this.termHeight = termHeight;
-        this.leftMargin = leftMargin;
-        this.rightMargin = rightMargin;
-        this.topMargin = topMargin;
-        this.bottomMargin = bottomMargin;
+
+        innerX = x + MARGIN;
+        innerY = y + MARGIN;
+        innerWidth = termWidth * FONT_WIDTH;
+        innerHeight = termHeight * FONT_HEIGHT;
     }
 
     @Override
@@ -65,7 +60,7 @@ public class WidgetTerminal implements IGuiEventListener
         if( ch >= 32 && ch <= 126 || ch >= 160 && ch <= 255 ) // printable chars in byte range
         {
             // Queue the "char" event
-            queueEvent( "char", Character.toString( ch ) );
+            computer.queueEvent( "char", new Object[] { Character.toString( ch ) } );
         }
 
         return true;
@@ -91,7 +86,7 @@ public class WidgetTerminal implements IGuiEventListener
 
                 case GLFW.GLFW_KEY_V:
                     // Ctrl+V for paste
-                    String clipboard = client.keyboardHandler.getClipboard();
+                    String clipboard = Minecraft.getInstance().keyboardHandler.getClipboard();
                     if( clipboard != null )
                     {
                         // Clip to the first occurrence of \r or \n
@@ -116,7 +111,7 @@ public class WidgetTerminal implements IGuiEventListener
                         {
                             // Clip to 512 characters and queue the event
                             if( clipboard.length() > 512 ) clipboard = clipboard.substring( 0, 512 );
-                            queueEvent( "paste", clipboard );
+                            computer.queueEvent( "paste", new Object[] { clipboard } );
                         }
 
                         return true;
@@ -129,8 +124,7 @@ public class WidgetTerminal implements IGuiEventListener
             // Queue the "key" event and add to the down set
             boolean repeat = keysDown.get( key );
             keysDown.set( key );
-            IComputer computer = this.computer.get();
-            if( computer != null ) computer.keyDown( key, repeat );
+            computer.keyDown( key, repeat );
         }
 
         return true;
@@ -143,8 +137,7 @@ public class WidgetTerminal implements IGuiEventListener
         if( key >= 0 && keysDown.get( key ) )
         {
             keysDown.set( key, false );
-            IComputer computer = this.computer.get();
-            if( computer != null ) computer.keyUp( key );
+            computer.keyUp( key );
         }
 
         switch( key )
@@ -170,14 +163,14 @@ public class WidgetTerminal implements IGuiEventListener
     @Override
     public boolean mouseClicked( double mouseX, double mouseY, int button )
     {
-        ClientComputer computer = this.computer.get();
-        if( computer == null || !computer.isColour() || button < 0 || button > 2 ) return false;
+        if( !inTermRegion( mouseX, mouseY ) ) return false;
+        if( !computer.isColour() || button < 0 || button > 2 ) return false;
 
         Terminal term = computer.getTerminal();
         if( term != null )
         {
-            int charX = (int) (mouseX / FONT_WIDTH);
-            int charY = (int) (mouseY / FONT_HEIGHT);
+            int charX = (int) ((mouseX - innerX) / FONT_WIDTH);
+            int charY = (int) ((mouseY - innerY) / FONT_HEIGHT);
             charX = Math.min( Math.max( charX, 0 ), term.getWidth() - 1 );
             charY = Math.min( Math.max( charY, 0 ), term.getHeight() - 1 );
 
@@ -194,14 +187,14 @@ public class WidgetTerminal implements IGuiEventListener
     @Override
     public boolean mouseReleased( double mouseX, double mouseY, int button )
     {
-        ClientComputer computer = this.computer.get();
-        if( computer == null || !computer.isColour() || button < 0 || button > 2 ) return false;
+        if( !inTermRegion( mouseX, mouseY ) ) return false;
+        if( !computer.isColour() || button < 0 || button > 2 ) return false;
 
         Terminal term = computer.getTerminal();
         if( term != null )
         {
-            int charX = (int) (mouseX / FONT_WIDTH);
-            int charY = (int) (mouseY / FONT_HEIGHT);
+            int charX = (int) ((mouseX - innerX) / FONT_WIDTH);
+            int charY = (int) ((mouseY - innerY) / FONT_HEIGHT);
             charX = Math.min( Math.max( charX, 0 ), term.getWidth() - 1 );
             charY = Math.min( Math.max( charY, 0 ), term.getHeight() - 1 );
 
@@ -221,14 +214,14 @@ public class WidgetTerminal implements IGuiEventListener
     @Override
     public boolean mouseDragged( double mouseX, double mouseY, int button, double v2, double v3 )
     {
-        ClientComputer computer = this.computer.get();
-        if( computer == null || !computer.isColour() || button < 0 || button > 2 ) return false;
+        if( !inTermRegion( mouseX, mouseY ) ) return false;
+        if( !computer.isColour() || button < 0 || button > 2 ) return false;
 
         Terminal term = computer.getTerminal();
         if( term != null )
         {
-            int charX = (int) (mouseX / FONT_WIDTH);
-            int charY = (int) (mouseY / FONT_HEIGHT);
+            int charX = (int) ((mouseX - innerX) / FONT_WIDTH);
+            int charY = (int) ((mouseY - innerY) / FONT_HEIGHT);
             charX = Math.min( Math.max( charX, 0 ), term.getWidth() - 1 );
             charY = Math.min( Math.max( charY, 0 ), term.getHeight() - 1 );
 
@@ -246,14 +239,14 @@ public class WidgetTerminal implements IGuiEventListener
     @Override
     public boolean mouseScrolled( double mouseX, double mouseY, double delta )
     {
-        ClientComputer computer = this.computer.get();
-        if( computer == null || !computer.isColour() || delta == 0 ) return false;
+        if( !inTermRegion( mouseX, mouseY ) ) return false;
+        if( !computer.isColour() || delta == 0 ) return false;
 
         Terminal term = computer.getTerminal();
         if( term != null )
         {
-            int charX = (int) (mouseX / FONT_WIDTH);
-            int charY = (int) (mouseY / FONT_HEIGHT);
+            int charX = (int) ((mouseX - innerX) / FONT_WIDTH);
+            int charY = (int) ((mouseY - innerY) / FONT_HEIGHT);
             charX = Math.min( Math.max( charX, 0 ), term.getWidth() - 1 );
             charY = Math.min( Math.max( charY, 0 ), term.getHeight() - 1 );
 
@@ -266,89 +259,74 @@ public class WidgetTerminal implements IGuiEventListener
         return true;
     }
 
+    private boolean inTermRegion( double mouseX, double mouseY )
+    {
+        return active && visible && mouseX >= innerX && mouseY >= innerY && mouseX < innerX + innerWidth && mouseY < innerY + innerHeight;
+    }
+
     public void update()
     {
         if( terminateTimer >= 0 && terminateTimer < TERMINATE_TIME && (terminateTimer += 0.05f) > TERMINATE_TIME )
         {
-            queueEvent( "terminate" );
+            computer.queueEvent( "terminate" );
         }
 
         if( shutdownTimer >= 0 && shutdownTimer < TERMINATE_TIME && (shutdownTimer += 0.05f) > TERMINATE_TIME )
         {
-            ClientComputer computer = this.computer.get();
-            if( computer != null ) computer.shutdown();
+            computer.shutdown();
         }
 
         if( rebootTimer >= 0 && rebootTimer < TERMINATE_TIME && (rebootTimer += 0.05f) > TERMINATE_TIME )
         {
-            ClientComputer computer = this.computer.get();
-            if( computer != null ) computer.reboot();
+            computer.reboot();
         }
     }
 
     @Override
-    public boolean changeFocus( boolean reversed )
+    public void onFocusedChanged( boolean focused )
     {
-        if( focused )
+        if( !focused )
         {
             // When blurring, we should make all keys go up
             for( int key = 0; key < keysDown.size(); key++ )
             {
-                if( keysDown.get( key ) ) queueEvent( "key_up", key );
+                if( keysDown.get( key ) ) computer.keyUp( key );
             }
             keysDown.clear();
 
             // When blurring, we should make the last mouse button go up
             if( lastMouseButton > 0 )
             {
-                IComputer computer = this.computer.get();
-                if( computer != null ) computer.mouseUp( lastMouseButton + 1, lastMouseX + 1, lastMouseY + 1 );
+                computer.mouseUp( lastMouseButton + 1, lastMouseX + 1, lastMouseY + 1 );
                 lastMouseButton = -1;
             }
 
             shutdownTimer = terminateTimer = rebootTimer = -1;
         }
-        focused = !focused;
-        return true;
-    }
-
-    public void draw( int originX, int originY )
-    {
-        synchronized( computer )
-        {
-            // Draw the screen contents
-            ClientComputer computer = this.computer.get();
-            Terminal terminal = computer != null ? computer.getTerminal() : null;
-            if( terminal != null )
-            {
-                FixedWidthFontRenderer.drawTerminal( originX, originY, terminal, !computer.isColour(), topMargin, bottomMargin, leftMargin, rightMargin );
-            }
-            else
-            {
-                FixedWidthFontRenderer.drawEmptyTerminal(
-                    originX - leftMargin, originY - rightMargin,
-                    termWidth * FONT_WIDTH + leftMargin + rightMargin,
-                    termHeight * FONT_HEIGHT + topMargin + bottomMargin
-                );
-            }
-        }
-    }
-
-    private void queueEvent( String event )
-    {
-        ClientComputer computer = this.computer.get();
-        if( computer != null ) computer.queueEvent( event );
-    }
-
-    private void queueEvent( String event, Object... args )
-    {
-        ClientComputer computer = this.computer.get();
-        if( computer != null ) computer.queueEvent( event, args );
     }
 
     @Override
-    public boolean isMouseOver( double x, double y )
+    public void render( int mouseX, int mouseY, float partialTicks )
     {
-        return true;
+        // Draw the screen contents
+        Terminal terminal = computer.getTerminal();
+        if( terminal != null )
+        {
+            FixedWidthFontRenderer.drawTerminal( innerX, innerY, terminal, !computer.isColour(), MARGIN, MARGIN, MARGIN, MARGIN );
+        }
+        else
+        {
+            FixedWidthFontRenderer.drawEmptyTerminal( x, y, width, height );
+        }
+    }
+
+    public static int getWidth( int termWidth )
+    {
+        return termWidth * FONT_WIDTH + MARGIN * 2;
+    }
+
+    public static int getHeight( int termHeight )
+    {
+        return termHeight * FONT_HEIGHT + MARGIN * 2;
     }
 }

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

@@ -1,105 +0,0 @@
-/*
- * This file is part of ComputerCraft - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
- * Send enquiries to dratcliffe@gmail.com
- */
-package dan200.computercraft.client.gui.widgets;
-
-import net.minecraft.client.gui.IGuiEventListener;
-
-public class WidgetWrapper implements IGuiEventListener
-{
-    private final IGuiEventListener listener;
-    private final int x;
-    private final int y;
-    private final int width;
-    private final int height;
-
-    public WidgetWrapper( IGuiEventListener listener, int x, int y, int width, int height )
-    {
-        this.listener = listener;
-        this.x = x;
-        this.y = y;
-        this.width = width;
-        this.height = height;
-    }
-
-    @Override
-    public boolean changeFocus( boolean b )
-    {
-        return listener.changeFocus( b );
-    }
-
-    @Override
-    public boolean mouseClicked( double x, double y, int button )
-    {
-        double dx = x - this.x, dy = y - this.y;
-        return dx >= 0 && dx < width && dy >= 0 && dy < height && listener.mouseClicked( dx, dy, button );
-    }
-
-    @Override
-    public boolean mouseReleased( double x, double y, int button )
-    {
-        double dx = x - this.x, dy = y - this.y;
-        return dx >= 0 && dx < width && dy >= 0 && dy < height && listener.mouseReleased( dx, dy, button );
-    }
-
-    @Override
-    public boolean mouseDragged( double x, double y, int button, double deltaX, double deltaY )
-    {
-        double dx = x - this.x, dy = y - this.y;
-        return dx >= 0 && dx < width && dy >= 0 && dy < height && listener.mouseDragged( dx, dy, button, deltaX, deltaY );
-    }
-
-    @Override
-    public boolean mouseScrolled( double x, double y, double delta )
-    {
-        double dx = x - this.x, dy = y - this.y;
-        return dx >= 0 && dx < width && dy >= 0 && dy < height && listener.mouseScrolled( dx, dy, delta );
-    }
-
-    @Override
-    public boolean keyPressed( int key, int scancode, int modifiers )
-    {
-        return listener.keyPressed( key, scancode, modifiers );
-    }
-
-    @Override
-    public boolean keyReleased( int key, int scancode, int modifiers )
-    {
-        return listener.keyReleased( key, scancode, modifiers );
-    }
-
-    @Override
-    public boolean charTyped( char character, int modifiers )
-    {
-        return listener.charTyped( character, modifiers );
-    }
-
-    public int getX()
-    {
-        return x;
-    }
-
-    public int getY()
-    {
-        return y;
-    }
-
-    public int getWidth()
-    {
-        return width;
-    }
-
-    public int getHeight()
-    {
-        return height;
-    }
-
-    @Override
-    public boolean isMouseOver( double x, double y )
-    {
-        double dx = x - this.x, dy = y - this.y;
-        return dx >= 0 && dx < width && dy >= 0 && dy < height;
-    }
-}

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

@@ -1,81 +0,0 @@
-/*
- * This file is part of ComputerCraft - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
- * Send enquiries to dratcliffe@gmail.com
- */
-package dan200.computercraft.client.proxy;
-
-import dan200.computercraft.ComputerCraft;
-import dan200.computercraft.client.gui.*;
-import dan200.computercraft.client.render.TileEntityMonitorRenderer;
-import dan200.computercraft.client.render.TileEntityTurtleRenderer;
-import dan200.computercraft.client.render.TurtlePlayerRenderer;
-import dan200.computercraft.shared.Registry;
-import dan200.computercraft.shared.computer.inventory.ContainerComputer;
-import dan200.computercraft.shared.computer.inventory.ContainerViewComputer;
-import dan200.computercraft.shared.peripheral.monitor.ClientMonitor;
-import dan200.computercraft.shared.pocket.inventory.ContainerPocketComputer;
-import net.minecraft.client.gui.ScreenManager;
-import net.minecraft.client.renderer.RenderType;
-import net.minecraft.client.renderer.RenderTypeLookup;
-import net.minecraftforge.api.distmarker.Dist;
-import net.minecraftforge.event.world.WorldEvent;
-import net.minecraftforge.eventbus.api.SubscribeEvent;
-import net.minecraftforge.fml.client.registry.ClientRegistry;
-import net.minecraftforge.fml.client.registry.RenderingRegistry;
-import net.minecraftforge.fml.common.Mod;
-import net.minecraftforge.fml.event.lifecycle.FMLClientSetupEvent;
-
-@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Dist.CLIENT, bus = Mod.EventBusSubscriber.Bus.MOD )
-public final class ComputerCraftProxyClient
-{
-    @SubscribeEvent
-    public static void setupClient( FMLClientSetupEvent event )
-    {
-        registerContainers();
-
-        // While turtles themselves are not transparent, their upgrades may be.
-        RenderTypeLookup.setRenderLayer( Registry.ModBlocks.TURTLE_NORMAL.get(), RenderType.translucent() );
-        RenderTypeLookup.setRenderLayer( Registry.ModBlocks.TURTLE_ADVANCED.get(), RenderType.translucent() );
-
-        // Monitors' textures have transparent fronts and so count as cutouts.
-        RenderTypeLookup.setRenderLayer( Registry.ModBlocks.MONITOR_NORMAL.get(), RenderType.cutout() );
-        RenderTypeLookup.setRenderLayer( Registry.ModBlocks.MONITOR_ADVANCED.get(), RenderType.cutout() );
-
-        // Setup TESRs
-        ClientRegistry.bindTileEntityRenderer( Registry.ModTiles.MONITOR_NORMAL.get(), TileEntityMonitorRenderer::new );
-        ClientRegistry.bindTileEntityRenderer( Registry.ModTiles.MONITOR_ADVANCED.get(), TileEntityMonitorRenderer::new );
-        ClientRegistry.bindTileEntityRenderer( Registry.ModTiles.TURTLE_NORMAL.get(), TileEntityTurtleRenderer::new );
-        ClientRegistry.bindTileEntityRenderer( Registry.ModTiles.TURTLE_ADVANCED.get(), TileEntityTurtleRenderer::new );
-
-        RenderingRegistry.registerEntityRenderingHandler( Registry.ModEntities.TURTLE_PLAYER.get(), TurtlePlayerRenderer::new );
-    }
-
-    private static void registerContainers()
-    {
-        // My IDE doesn't think so, but we do actually need these generics.
-
-        ScreenManager.<ContainerComputer, GuiComputer<ContainerComputer>>register( Registry.ModContainers.COMPUTER.get(), GuiComputer::create );
-        ScreenManager.<ContainerPocketComputer, GuiComputer<ContainerPocketComputer>>register( Registry.ModContainers.POCKET_COMPUTER.get(), GuiComputer::createPocket );
-        ScreenManager.register( Registry.ModContainers.TURTLE.get(), GuiTurtle::new );
-
-        ScreenManager.register( Registry.ModContainers.PRINTER.get(), GuiPrinter::new );
-        ScreenManager.register( Registry.ModContainers.DISK_DRIVE.get(), GuiDiskDrive::new );
-        ScreenManager.register( Registry.ModContainers.PRINTOUT.get(), GuiPrintout::new );
-
-        ScreenManager.<ContainerViewComputer, GuiComputer<ContainerViewComputer>>register( Registry.ModContainers.VIEW_COMPUTER.get(), GuiComputer::createView );
-    }
-
-    @Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Dist.CLIENT )
-    public static final class ForgeHandlers
-    {
-        @SubscribeEvent
-        public static void onWorldUnload( WorldEvent.Unload event )
-        {
-            if( event.getWorld().isClientSide() )
-            {
-                ClientMonitor.destroyAll();
-            }
-        }
-    }
-}

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

@@ -52,7 +52,8 @@ public class ComputerBorderRenderer
 
     public static final int LIGHT_HEIGHT = 8;
 
-    private static final float TEX_SCALE = 1 / 256.0f;
+    public static final int TEX_SIZE = 256;
+    private static final float TEX_SCALE = 1 / (float) TEX_SIZE;
 
     private final Matrix4f transform;
     private final IVertexBuilder builder;

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

@@ -37,7 +37,7 @@ public class HTTPAPI implements ILuaAPI
 {
     private final IAPIEnvironment apiEnvironment;
 
-    private final ResourceGroup<CheckUrl> checkUrls = new ResourceGroup<>();
+    private final ResourceGroup<CheckUrl> checkUrls = new ResourceGroup<>( ResourceGroup.DEFAULT );
     private final ResourceGroup<HttpRequest> requests = new ResourceQueue<>( () -> ComputerCraft.httpMaxRequests );
     private final ResourceGroup<Websocket> websockets = new ResourceGroup<>( () -> ComputerCraft.httpMaxWebsockets );
 
@@ -127,7 +127,10 @@ public class HTTPAPI implements ILuaAPI
             HttpRequest request = new HttpRequest( requests, apiEnvironment, address, postString, headers, binary, redirect );
 
             // Make the request
-            request.queue( r -> r.request( uri, httpMethod ) );
+            if( !request.queue( r -> r.request( uri, httpMethod ) ) )
+            {
+                throw new LuaException( "Too many ongoing HTTP requests" );
+            }
 
             return new Object[] { true };
         }
@@ -138,12 +141,15 @@ public class HTTPAPI implements ILuaAPI
     }
 
     @LuaFunction
-    public final Object[] checkURL( String address )
+    public final Object[] checkURL( String address ) throws LuaException
     {
         try
         {
             URI uri = HttpRequest.checkUri( address );
-            new CheckUrl( checkUrls, apiEnvironment, address, uri ).queue( CheckUrl::run );
+            if( !new CheckUrl( checkUrls, apiEnvironment, address, uri ).queue( CheckUrl::run ) )
+            {
+                throw new LuaException( "Too many ongoing checkUrl calls" );
+            }
 
             return new Object[] { true };
         }

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

@@ -11,12 +11,19 @@ import dan200.computercraft.core.apis.http.options.AddressRule;
 import dan200.computercraft.core.apis.http.options.Options;
 import dan200.computercraft.shared.util.ThreadUtils;
 import io.netty.buffer.ByteBuf;
+import io.netty.channel.ConnectTimeoutException;
 import io.netty.channel.EventLoopGroup;
 import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.handler.codec.DecoderException;
+import io.netty.handler.codec.TooLongFrameException;
+import io.netty.handler.codec.http.websocketx.WebSocketHandshakeException;
 import io.netty.handler.ssl.SslContext;
 import io.netty.handler.ssl.SslContextBuilder;
+import io.netty.handler.timeout.ReadTimeoutException;
 
+import javax.annotation.Nonnull;
 import javax.net.ssl.SSLException;
+import javax.net.ssl.SSLHandshakeException;
 import javax.net.ssl.TrustManagerFactory;
 import java.net.InetSocketAddress;
 import java.net.URI;
@@ -161,4 +168,29 @@ public final class NetworkUtils
         buffer.readBytes( bytes );
         return bytes;
     }
+
+    @Nonnull
+    public static String toFriendlyError( @Nonnull Throwable cause )
+    {
+        if( cause instanceof WebSocketHandshakeException || cause instanceof HTTPRequestException )
+        {
+            return cause.getMessage();
+        }
+        else if( cause instanceof TooLongFrameException )
+        {
+            return "Message is too large";
+        }
+        else if( cause instanceof ReadTimeoutException || cause instanceof ConnectTimeoutException )
+        {
+            return "Timed out";
+        }
+        else if( cause instanceof SSLHandshakeException || (cause instanceof DecoderException && cause.getCause() instanceof SSLHandshakeException) )
+        {
+            return "Could not create a secure connection";
+        }
+        else
+        {
+            return "Could not connect";
+        }
+    }
 }

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

@@ -97,7 +97,7 @@ public abstract class Resource<T extends Resource<T>> implements Closeable
         tryClose();
     }
 
-    public boolean queue( Consumer<T> task )
+    public final boolean queue( Consumer<T> task )
     {
         @SuppressWarnings( "unchecked" )
         T thisT = (T) this;

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

@@ -18,6 +18,9 @@ import java.util.function.Supplier;
  */
 public class ResourceGroup<T extends Resource<T>>
 {
+    public static final int DEFAULT_LIMIT = 512;
+    public static final IntSupplier DEFAULT = () -> DEFAULT_LIMIT;
+
     private static final IntSupplier ZERO = () -> 0;
 
     final IntSupplier limit;

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

@@ -38,8 +38,10 @@ public class ResourceQueue<T extends Resource<T>> extends ResourceGroup<T>
     public synchronized boolean queue( Supplier<T> resource )
     {
         if( !active ) return false;
+        if( super.queue( resource ) ) return true;
+        if( pending.size() > DEFAULT_LIMIT ) return false;
 
-        if( !super.queue( resource ) ) pending.add( resource );
+        pending.add( resource );
         return true;
     }
 

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

@@ -19,13 +19,10 @@ import io.netty.buffer.Unpooled;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelPipeline;
-import io.netty.channel.ConnectTimeoutException;
 import io.netty.channel.socket.SocketChannel;
 import io.netty.channel.socket.nio.NioSocketChannel;
-import io.netty.handler.codec.TooLongFrameException;
 import io.netty.handler.codec.http.*;
 import io.netty.handler.ssl.SslContext;
-import io.netty.handler.timeout.ReadTimeoutException;
 import io.netty.handler.timeout.ReadTimeoutHandler;
 
 import java.net.InetSocketAddress;
@@ -190,7 +187,7 @@ public class HttpRequest extends Resource<HttpRequest>
                 .remoteAddress( socketAddress )
                 .connect()
                 .addListener( c -> {
-                    if( !c.isSuccess() ) failure( c.cause() );
+                    if( !c.isSuccess() ) failure( NetworkUtils.toFriendlyError( c.cause() ) );
                 } );
 
             // Do an additional check for cancellation
@@ -202,7 +199,7 @@ public class HttpRequest extends Resource<HttpRequest>
         }
         catch( Exception e )
         {
-            failure( "Could not connect" );
+            failure( NetworkUtils.toFriendlyError( e ) );
             if( ComputerCraft.logComputerErrors ) ComputerCraft.log.error( "Error in HTTP request", e );
         }
     }
@@ -212,29 +209,6 @@ public class HttpRequest extends Resource<HttpRequest>
         if( tryClose() ) environment.queueEvent( FAILURE_EVENT, address, message );
     }
 
-    void failure( Throwable cause )
-    {
-        String message;
-        if( cause instanceof HTTPRequestException )
-        {
-            message = cause.getMessage();
-        }
-        else if( cause instanceof TooLongFrameException )
-        {
-            message = "Response is too large";
-        }
-        else if( cause instanceof ReadTimeoutException || cause instanceof ConnectTimeoutException )
-        {
-            message = "Timed out";
-        }
-        else
-        {
-            message = "Could not connect";
-        }
-
-        failure( message );
-    }
-
     void failure( String message, HttpResponseHandle object )
     {
         if( tryClose() ) environment.queueEvent( FAILURE_EVENT, address, message, object );

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

@@ -183,7 +183,7 @@ public final class HttpRequestHandler extends SimpleChannelInboundHandler<HttpOb
     public void exceptionCaught( ChannelHandlerContext ctx, Throwable cause )
     {
         if( ComputerCraft.logComputerErrors ) ComputerCraft.log.error( "Error handling HTTP response", cause );
-        request.failure( cause );
+        request.failure( NetworkUtils.toFriendlyError( cause ) );
     }
 
     private void sendResponse()

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

@@ -22,6 +22,7 @@ import io.netty.channel.ChannelPipeline;
 import io.netty.channel.socket.SocketChannel;
 import io.netty.channel.socket.nio.NioSocketChannel;
 import io.netty.handler.codec.http.HttpClientCodec;
+import io.netty.handler.codec.http.HttpHeaderNames;
 import io.netty.handler.codec.http.HttpHeaders;
 import io.netty.handler.codec.http.HttpObjectAggregator;
 import io.netty.handler.codec.http.websocketx.WebSocketClientHandshaker;
@@ -150,8 +151,9 @@ public class Websocket extends Resource<Websocket>
                             p.addLast( sslContext.newHandler( ch.alloc(), uri.getHost(), socketAddress.getPort() ) );
                         }
 
+                        String subprotocol = headers.get( HttpHeaderNames.SEC_WEBSOCKET_PROTOCOL );
                         WebSocketClientHandshaker handshaker = WebSocketClientHandshakerFactory.newHandshaker(
-                            uri, WebSocketVersion.V13, null, true, headers,
+                            uri, WebSocketVersion.V13, subprotocol, true, headers,
                             options.websocketMessage <= 0 ? MAX_MESSAGE_SIZE : options.websocketMessage
                         );
 
@@ -166,7 +168,7 @@ public class Websocket extends Resource<Websocket>
                 .remoteAddress( socketAddress )
                 .connect()
                 .addListener( c -> {
-                    if( !c.isSuccess() ) failure( c.cause().getMessage() );
+                    if( !c.isSuccess() ) failure( NetworkUtils.toFriendlyError( c.cause() ) );
                 } );
 
             // Do an additional check for cancellation
@@ -178,7 +180,7 @@ public class Websocket extends Resource<Websocket>
         }
         catch( Exception e )
         {
-            failure( "Could not connect" );
+            failure( NetworkUtils.toFriendlyError( e ) );
             if( ComputerCraft.logComputerErrors ) ComputerCraft.log.error( "Error in websocket", e );
         }
     }

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

@@ -5,17 +5,13 @@
  */
 package dan200.computercraft.core.apis.http.websocket;
 
-import dan200.computercraft.core.apis.http.HTTPRequestException;
 import dan200.computercraft.core.apis.http.NetworkUtils;
 import dan200.computercraft.core.apis.http.options.Options;
 import dan200.computercraft.core.tracking.TrackingField;
 import io.netty.channel.ChannelHandlerContext;
-import io.netty.channel.ConnectTimeoutException;
 import io.netty.channel.SimpleChannelInboundHandler;
-import io.netty.handler.codec.TooLongFrameException;
 import io.netty.handler.codec.http.FullHttpResponse;
 import io.netty.handler.codec.http.websocketx.*;
-import io.netty.handler.timeout.ReadTimeoutException;
 import io.netty.util.CharsetUtil;
 
 import static dan200.computercraft.core.apis.http.websocket.Websocket.MESSAGE_EVENT;
@@ -97,24 +93,7 @@ public class WebsocketHandler extends SimpleChannelInboundHandler<Object>
     {
         ctx.close();
 
-        String message;
-        if( cause instanceof WebSocketHandshakeException || cause instanceof HTTPRequestException )
-        {
-            message = cause.getMessage();
-        }
-        else if( cause instanceof TooLongFrameException )
-        {
-            message = "Message is too large";
-        }
-        else if( cause instanceof ReadTimeoutException || cause instanceof ConnectTimeoutException )
-        {
-            message = "Timed out";
-        }
-        else
-        {
-            message = "Could not connect";
-        }
-
+        String message = NetworkUtils.toFriendlyError( cause );
         if( handshaker.isHandshakeComplete() )
         {
             websocket.close( -1, message );

src/main/java/dan200/computercraft/core/asm/Generator.java

@@ -11,7 +11,10 @@ import com.google.common.cache.LoadingCache;
 import com.google.common.primitives.Primitives;
 import com.google.common.reflect.TypeToken;
 import dan200.computercraft.ComputerCraft;
-import dan200.computercraft.api.lua.*;
+import dan200.computercraft.api.lua.IArguments;
+import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.api.lua.LuaFunction;
+import dan200.computercraft.api.lua.MethodResult;
 import org.objectweb.asm.ClassWriter;
 import org.objectweb.asm.MethodVisitor;
 import org.objectweb.asm.Type;
@@ -63,7 +66,7 @@ public final class Generator<T>
     {
         this.base = base;
         this.context = context;
-        this.interfaces = new String[] { Type.getInternalName( base ) };
+        interfaces = new String[] { Type.getInternalName( base ) };
         this.wrap = wrap;
 
         StringBuilder methodDesc = new StringBuilder().append( "(Ljava/lang/Object;" );

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

@@ -251,6 +251,20 @@ final class ComputerExecutor
      * and then schedule a shutdown.
      */
     void abort()
+    {
+        immediateFail( StateCommand.ABORT );
+    }
+
+    /**
+     * Abort this whole computer due to an internal error. This will immediately destroy the Lua machine,
+     * and then schedule a shutdown.
+     */
+    void fastFail()
+    {
+        immediateFail( StateCommand.ERROR );
+    }
+
+    private void immediateFail( StateCommand command )
     {
         ILuaMachine machine = this.machine;
         if( machine != null ) machine.close();
@@ -258,7 +272,7 @@ final class ComputerExecutor
         synchronized( queueLock )
         {
             if( closed ) return;
-            command = StateCommand.ABORT;
+            this.command = command;
             if( isOn ) enqueue();
         }
     }
@@ -596,6 +610,12 @@ final class ComputerExecutor
                     displayFailure( "Error running computer", TimeoutState.ABORT_MESSAGE );
                     shutdown();
                     break;
+
+                case ERROR:
+                    if( !isOn ) return;
+                    displayFailure( "Error running computer", "An internal error occurred, see logs." );
+                    shutdown();
+                    break;
             }
         }
         else if( event != null )
@@ -644,6 +664,7 @@ final class ComputerExecutor
         SHUTDOWN,
         REBOOT,
         ABORT,
+        ERROR,
     }
 
     private static final class Event

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

@@ -506,6 +506,8 @@ public final class ComputerThread
                 catch( Exception | LinkageError | VirtualMachineError e )
                 {
                     ComputerCraft.log.error( "Error running task on computer #" + executor.getComputer().getID(), e );
+                    // Tear down the computer immediately. There's no guarantee it's well behaved from now on.
+                    executor.fastFail();
                 }
                 finally
                 {

src/main/java/dan200/computercraft/core/lua/CobaltLuaMachine.java

@@ -10,7 +10,6 @@ import dan200.computercraft.api.lua.*;
 import dan200.computercraft.core.asm.LuaMethod;
 import dan200.computercraft.core.asm.ObjectSource;
 import dan200.computercraft.core.computer.Computer;
-import dan200.computercraft.core.computer.MainThread;
 import dan200.computercraft.core.computer.TimeoutState;
 import dan200.computercraft.core.tracking.Tracking;
 import dan200.computercraft.core.tracking.TrackingField;
@@ -53,7 +52,7 @@ public class CobaltLuaMachine implements ILuaMachine
     private final Computer computer;
     private final TimeoutState timeout;
     private final TimeoutDebugHandler debug;
-    private final ILuaContext context = new CobaltLuaContext();
+    private final ILuaContext context;
 
     private LuaState state;
     private LuaTable globals;
@@ -65,6 +64,7 @@ public class CobaltLuaMachine implements ILuaMachine
     {
         this.computer = computer;
         this.timeout = timeout;
+        context = new LuaContext( computer );
         debug = new TimeoutDebugHandler();
 
         // Create an environment to run in
@@ -97,7 +97,7 @@ public class CobaltLuaMachine implements ILuaMachine
         globals.load( state, new CoroutineLib() );
         globals.load( state, new Bit32Lib() );
         globals.load( state, new Utf8Lib() );
-        if( ComputerCraft.debugEnable ) globals.load( state, new DebugLib() );
+        globals.load( state, new DebugLib() );
 
         // Remove globals we don't want to expose
         globals.rawset( "collectgarbage", Constants.NIL );
@@ -509,53 +509,6 @@ public class CobaltLuaMachine implements ILuaMachine
         }
     }
 
-    private class CobaltLuaContext implements ILuaContext
-    {
-        @Override
-        public long issueMainThreadTask( @Nonnull final ILuaTask task ) throws LuaException
-        {
-            // Issue command
-            final long taskID = MainThread.getUniqueTaskID();
-            final Runnable iTask = () -> {
-                try
-                {
-                    Object[] results = task.execute();
-                    if( results != null )
-                    {
-                        Object[] eventArguments = new Object[results.length + 2];
-                        eventArguments[0] = taskID;
-                        eventArguments[1] = true;
-                        System.arraycopy( results, 0, eventArguments, 2, results.length );
-                        computer.queueEvent( "task_complete", eventArguments );
-                    }
-                    else
-                    {
-                        computer.queueEvent( "task_complete", new Object[] { taskID, true } );
-                    }
-                }
-                catch( LuaException e )
-                {
-                    computer.queueEvent( "task_complete", new Object[] { taskID, false, e.getMessage() } );
-                }
-                catch( Throwable t )
-                {
-                    if( ComputerCraft.logComputerErrors ) ComputerCraft.log.error( "Error running task", t );
-                    computer.queueEvent( "task_complete", new Object[] {
-                        taskID, false, "Java Exception Thrown: " + t,
-                    } );
-                }
-            };
-            if( computer.queueMainThread( iTask ) )
-            {
-                return taskID;
-            }
-            else
-            {
-                throw new LuaException( "Task limit exceeded" );
-            }
-        }
-    }
-
     private static final class HardAbortError extends Error
     {
         private static final long serialVersionUID = 7954092008586367501L;

src/main/java/dan200/computercraft/core/lua/LuaContext.java

@@ -0,0 +1,69 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.core.lua;
+
+import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.api.lua.ILuaContext;
+import dan200.computercraft.api.lua.ILuaTask;
+import dan200.computercraft.api.lua.LuaException;
+import dan200.computercraft.core.computer.Computer;
+import dan200.computercraft.core.computer.MainThread;
+
+import javax.annotation.Nonnull;
+
+class LuaContext implements ILuaContext
+{
+    private final Computer computer;
+
+    LuaContext( Computer computer )
+    {
+        this.computer = computer;
+    }
+
+    @Override
+    public long issueMainThreadTask( @Nonnull final ILuaTask task ) throws LuaException
+    {
+        // Issue command
+        final long taskID = MainThread.getUniqueTaskID();
+        final Runnable iTask = () -> {
+            try
+            {
+                Object[] results = task.execute();
+                if( results != null )
+                {
+                    Object[] eventArguments = new Object[results.length + 2];
+                    eventArguments[0] = taskID;
+                    eventArguments[1] = true;
+                    System.arraycopy( results, 0, eventArguments, 2, results.length );
+                    computer.queueEvent( "task_complete", eventArguments );
+                }
+                else
+                {
+                    computer.queueEvent( "task_complete", new Object[] { taskID, true } );
+                }
+            }
+            catch( LuaException e )
+            {
+                computer.queueEvent( "task_complete", new Object[] { taskID, false, e.getMessage() } );
+            }
+            catch( Exception t )
+            {
+                if( ComputerCraft.logComputerErrors ) ComputerCraft.log.error( "Error running task", t );
+                computer.queueEvent( "task_complete", new Object[] {
+                    taskID, false, "Java Exception Thrown: " + t,
+                } );
+            }
+        };
+        if( computer.queueMainThread( iTask ) )
+        {
+            return taskID;
+        }
+        else
+        {
+            throw new LuaException( "Task limit exceeded" );
+        }
+    }
+}

src/main/java/dan200/computercraft/core/terminal/Terminal.java

@@ -44,9 +44,9 @@ public class Terminal
         this.height = height;
         onChanged = changedCallback;
 
-        text = new TextBuffer[this.height];
-        textColour = new TextBuffer[this.height];
-        backgroundColour = new TextBuffer[this.height];
+        text = new TextBuffer[height];
+        textColour = new TextBuffer[height];
+        backgroundColour = new TextBuffer[height];
         for( int i = 0; i < this.height; i++ )
         {
             text[i] = new TextBuffer( ' ', this.width );
@@ -93,9 +93,9 @@ public class Terminal
         this.width = width;
         this.height = height;
 
-        text = new TextBuffer[this.height];
-        textColour = new TextBuffer[this.height];
-        backgroundColour = new TextBuffer[this.height];
+        text = new TextBuffer[height];
+        textColour = new TextBuffer[height];
+        backgroundColour = new TextBuffer[height];
         for( int i = 0; i < this.height; i++ )
         {
             if( i >= oldHeight )

src/main/java/dan200/computercraft/core/terminal/TextBuffer.java

@@ -12,7 +12,7 @@ public class TextBuffer
     public TextBuffer( char c, int length )
     {
         text = new char[length];
-        this.fill( c );
+        fill( c );
     }
 
     public TextBuffer( String text )
@@ -79,6 +79,7 @@ public class TextBuffer
         }
     }
 
+    @Override
     public String toString()
     {
         return new String( text );

src/main/java/dan200/computercraft/data/Generators.java

@@ -5,7 +5,7 @@
  */
 package dan200.computercraft.data;
 
-import dan200.computercraft.shared.proxy.ComputerCraftProxyCommon;
+import dan200.computercraft.shared.Registry;
 import net.minecraft.data.DataGenerator;
 import net.minecraftforge.eventbus.api.SubscribeEvent;
 import net.minecraftforge.fml.common.Mod;
@@ -17,7 +17,7 @@ public class Generators
     @SubscribeEvent
     public static void gather( GatherDataEvent event )
     {
-        ComputerCraftProxyCommon.registerLoot();
+        Registry.registerLoot();
 
         DataGenerator generator = event.getGenerator();
         generator.addProvider( new Recipes( generator ) );

src/main/java/dan200/computercraft/data/LootTables.java

@@ -6,11 +6,11 @@
 package dan200.computercraft.data;
 
 import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.shared.CommonHooks;
 import dan200.computercraft.shared.Registry;
 import dan200.computercraft.shared.data.BlockNamedEntityLootCondition;
 import dan200.computercraft.shared.data.HasComputerIdLootCondition;
 import dan200.computercraft.shared.data.PlayerCreativeLootCondition;
-import dan200.computercraft.shared.proxy.ComputerCraftProxyCommon;
 import net.minecraft.block.Block;
 import net.minecraft.data.DataGenerator;
 import net.minecraft.util.ResourceLocation;
@@ -46,7 +46,7 @@ public class LootTables extends LootTableProvider
         computerDrop( add, Registry.ModBlocks.TURTLE_NORMAL );
         computerDrop( add, Registry.ModBlocks.TURTLE_ADVANCED );
 
-        add.accept( ComputerCraftProxyCommon.ForgeHandlers.LOOT_TREASURE_DISK, LootTable
+        add.accept( CommonHooks.LOOT_TREASURE_DISK, LootTable
             .lootTable()
             .setParamSet( LootParameterSets.ALL_PARAMS )
             .build() );

src/main/java/dan200/computercraft/shared/CommonHooks.java

@@ -0,0 +1,123 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.shared;
+
+import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.core.computer.MainThread;
+import dan200.computercraft.core.tracking.Tracking;
+import dan200.computercraft.shared.command.CommandComputerCraft;
+import dan200.computercraft.shared.computer.core.IComputer;
+import dan200.computercraft.shared.computer.core.IContainerComputer;
+import dan200.computercraft.shared.computer.core.ServerComputer;
+import dan200.computercraft.shared.peripheral.modem.wireless.WirelessNetwork;
+import net.minecraft.inventory.container.Container;
+import net.minecraft.util.ResourceLocation;
+import net.minecraft.world.storage.loot.ConstantRange;
+import net.minecraft.world.storage.loot.LootPool;
+import net.minecraft.world.storage.loot.LootTables;
+import net.minecraft.world.storage.loot.TableLootEntry;
+import net.minecraftforge.event.LootTableLoadEvent;
+import net.minecraftforge.event.TickEvent;
+import net.minecraftforge.event.entity.player.PlayerContainerEvent;
+import net.minecraftforge.eventbus.api.SubscribeEvent;
+import net.minecraftforge.fml.common.Mod;
+import net.minecraftforge.fml.event.server.FMLServerStartedEvent;
+import net.minecraftforge.fml.event.server.FMLServerStartingEvent;
+import net.minecraftforge.fml.event.server.FMLServerStoppedEvent;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Miscellaneous hooks which are present on the client and server.
+ *
+ * These should possibly be refactored into separate classes at some point, but are fine here for now.
+ *
+ * @see dan200.computercraft.client.ClientHooks For client-specific ones.
+ */
+@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID )
+public final class CommonHooks
+{
+    private CommonHooks()
+    {
+    }
+
+    @SubscribeEvent
+    public static void onServerTick( TickEvent.ServerTickEvent event )
+    {
+        if( event.phase == TickEvent.Phase.START )
+        {
+            MainThread.executePendingTasks();
+            ComputerCraft.serverComputerRegistry.update();
+        }
+    }
+
+    @SubscribeEvent
+    public static void onContainerOpen( PlayerContainerEvent.Open event )
+    {
+        // If we're opening a computer container then broadcast the terminal state
+        Container container = event.getContainer();
+        if( container instanceof IContainerComputer )
+        {
+            IComputer computer = ((IContainerComputer) container).getComputer();
+            if( computer instanceof ServerComputer )
+            {
+                ((ServerComputer) computer).sendTerminalState( event.getPlayer() );
+            }
+        }
+    }
+
+    @SubscribeEvent
+    public static void onServerStarting( FMLServerStartingEvent event )
+    {
+        CommandComputerCraft.register( event.getCommandDispatcher() );
+    }
+
+    @SubscribeEvent
+    public static void onServerStarted( FMLServerStartedEvent event )
+    {
+        ComputerCraft.serverComputerRegistry.reset();
+        WirelessNetwork.resetNetworks();
+        Tracking.reset();
+    }
+
+    @SubscribeEvent
+    public static void onServerStopped( FMLServerStoppedEvent event )
+    {
+        ComputerCraft.serverComputerRegistry.reset();
+        WirelessNetwork.resetNetworks();
+        Tracking.reset();
+    }
+
+    public static final ResourceLocation LOOT_TREASURE_DISK = new ResourceLocation( ComputerCraft.MOD_ID, "treasure_disk" );
+
+    private static final Set<ResourceLocation> TABLES = new HashSet<>( Arrays.asList(
+        LootTables.SIMPLE_DUNGEON,
+        LootTables.ABANDONED_MINESHAFT,
+        LootTables.STRONGHOLD_CORRIDOR,
+        LootTables.STRONGHOLD_CROSSING,
+        LootTables.STRONGHOLD_LIBRARY,
+        LootTables.DESERT_PYRAMID,
+        LootTables.JUNGLE_TEMPLE,
+        LootTables.IGLOO_CHEST,
+        LootTables.WOODLAND_MANSION,
+        LootTables.VILLAGE_CARTOGRAPHER
+    ) );
+
+    @SubscribeEvent
+    public static void lootLoad( LootTableLoadEvent event )
+    {
+        ResourceLocation name = event.getName();
+        if( !name.getNamespace().equals( "minecraft" ) || !TABLES.contains( name ) ) return;
+
+        event.getTable().addPool( LootPool.lootPool()
+            .add( TableLootEntry.lootTableReference( LOOT_TREASURE_DISK ) )
+            .setRolls( ConstantRange.exactly( 1 ) )
+            .name( "computercraft_treasure" )
+            .build() );
+    }
+}

src/main/java/dan200/computercraft/shared/Config.java

@@ -42,7 +42,6 @@ public final class Config
     private static final ConfigValue<Integer> maximumFilesOpen;
     private static final ConfigValue<Boolean> disableLua51Features;
     private static final ConfigValue<String> defaultComputerSettings;
-    private static final ConfigValue<Boolean> debugEnabled;
     private static final ConfigValue<Boolean> logComputerErrors;
     private static final ConfigValue<Boolean> commandRequireCreative;
 
@@ -120,10 +119,6 @@ public final class Config
                     "autocompletion" )
                 .define( "default_computer_settings", ComputerCraft.defaultComputerSettings );
 
-            debugEnabled = builder
-                .comment( "Enable Lua's debug library. This is sandboxed to each computer, so is generally safe to be used by players." )
-                .define( "debug_enabled", ComputerCraft.debugEnable );
-
             logComputerErrors = builder
                 .comment( "Log exceptions thrown by peripherals and other Lua objects.\n" +
                     "This makes it easier for mod authors to debug problems, but may result in log spam should people use buggy methods." )
@@ -317,7 +312,6 @@ public final class Config
         ComputerCraft.maximumFilesOpen = maximumFilesOpen.get();
         ComputerCraft.disableLua51Features = disableLua51Features.get();
         ComputerCraft.defaultComputerSettings = defaultComputerSettings.get();
-        ComputerCraft.debugEnable = debugEnabled.get();
         ComputerCraft.computerThreads = computerThreads.get();
         ComputerCraft.logComputerErrors = logComputerErrors.get();
         ComputerCraft.commandRequireCreative = commandRequireCreative.get();

src/main/java/dan200/computercraft/shared/Registry.java

@@ -7,8 +7,13 @@ package dan200.computercraft.shared;
 
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.api.ComputerCraftAPI;
+import dan200.computercraft.api.media.IMedia;
+import dan200.computercraft.api.network.wired.IWiredElement;
+import dan200.computercraft.api.peripheral.IPeripheral;
+import dan200.computercraft.shared.command.arguments.ArgumentSerializers;
 import dan200.computercraft.shared.common.ColourableRecipe;
 import dan200.computercraft.shared.common.ContainerHeldItem;
+import dan200.computercraft.shared.common.DefaultBundledRedstoneProvider;
 import dan200.computercraft.shared.computer.blocks.BlockComputer;
 import dan200.computercraft.shared.computer.blocks.TileCommandComputer;
 import dan200.computercraft.shared.computer.blocks.TileComputer;
@@ -17,11 +22,17 @@ import dan200.computercraft.shared.computer.inventory.ContainerComputer;
 import dan200.computercraft.shared.computer.inventory.ContainerViewComputer;
 import dan200.computercraft.shared.computer.items.ItemComputer;
 import dan200.computercraft.shared.computer.recipe.ComputerUpgradeRecipe;
+import dan200.computercraft.shared.data.BlockNamedEntityLootCondition;
+import dan200.computercraft.shared.data.ConstantLootConditionSerializer;
+import dan200.computercraft.shared.data.HasComputerIdLootCondition;
+import dan200.computercraft.shared.data.PlayerCreativeLootCondition;
 import dan200.computercraft.shared.media.items.ItemDisk;
 import dan200.computercraft.shared.media.items.ItemPrintout;
 import dan200.computercraft.shared.media.items.ItemTreasureDisk;
+import dan200.computercraft.shared.media.items.RecordMedia;
 import dan200.computercraft.shared.media.recipes.DiskRecipe;
 import dan200.computercraft.shared.media.recipes.PrintoutRecipe;
+import dan200.computercraft.shared.network.NetworkHandler;
 import dan200.computercraft.shared.network.container.ComputerContainerData;
 import dan200.computercraft.shared.network.container.ContainerData;
 import dan200.computercraft.shared.network.container.HeldItemContainerData;
@@ -29,6 +40,9 @@ import dan200.computercraft.shared.network.container.ViewComputerContainerData;
 import dan200.computercraft.shared.peripheral.diskdrive.BlockDiskDrive;
 import dan200.computercraft.shared.peripheral.diskdrive.ContainerDiskDrive;
 import dan200.computercraft.shared.peripheral.diskdrive.TileDiskDrive;
+import dan200.computercraft.shared.peripheral.generic.methods.EnergyMethods;
+import dan200.computercraft.shared.peripheral.generic.methods.FluidMethods;
+import dan200.computercraft.shared.peripheral.generic.methods.InventoryMethods;
 import dan200.computercraft.shared.peripheral.modem.wired.*;
 import dan200.computercraft.shared.peripheral.modem.wireless.BlockWirelessModem;
 import dan200.computercraft.shared.peripheral.modem.wireless.TileWirelessModem;
@@ -52,29 +66,30 @@ import dan200.computercraft.shared.turtle.items.ItemTurtle;
 import dan200.computercraft.shared.turtle.recipes.TurtleRecipe;
 import dan200.computercraft.shared.turtle.recipes.TurtleUpgradeRecipe;
 import dan200.computercraft.shared.turtle.upgrades.*;
-import dan200.computercraft.shared.util.CreativeTabMain;
-import dan200.computercraft.shared.util.FixedPointTileEntityType;
-import dan200.computercraft.shared.util.ImpostorRecipe;
-import dan200.computercraft.shared.util.ImpostorShapelessRecipe;
+import dan200.computercraft.shared.util.*;
 import net.minecraft.block.Block;
 import net.minecraft.block.material.Material;
 import net.minecraft.entity.EntityClassification;
 import net.minecraft.entity.EntityType;
 import net.minecraft.inventory.container.ContainerType;
-import net.minecraft.item.BlockItem;
-import net.minecraft.item.Item;
-import net.minecraft.item.ItemGroup;
-import net.minecraft.item.Items;
+import net.minecraft.item.*;
 import net.minecraft.item.crafting.IRecipeSerializer;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.tileentity.TileEntityType;
 import net.minecraft.util.ResourceLocation;
+import net.minecraft.world.storage.loot.conditions.LootConditionManager;
+import net.minecraftforge.common.capabilities.CapabilityManager;
+import net.minecraftforge.energy.CapabilityEnergy;
 import net.minecraftforge.event.RegistryEvent;
 import net.minecraftforge.eventbus.api.IEventBus;
 import net.minecraftforge.eventbus.api.SubscribeEvent;
+import net.minecraftforge.fluids.capability.CapabilityFluidHandler;
+import net.minecraftforge.fml.DeferredWorkQueue;
 import net.minecraftforge.fml.RegistryObject;
 import net.minecraftforge.fml.common.Mod;
+import net.minecraftforge.fml.event.lifecycle.FMLCommonSetupEvent;
 import net.minecraftforge.fml.javafmlmod.FMLJavaModLoadingContext;
+import net.minecraftforge.items.CapabilityItemHandler;
 import net.minecraftforge.registries.DeferredRegister;
 import net.minecraftforge.registries.ForgeRegistries;
 
@@ -333,6 +348,68 @@ public final class Registry
         );
     }
 
+    @SubscribeEvent
+    @SuppressWarnings( "deprecation" )
+    public static void init( FMLCommonSetupEvent event )
+    {
+        NetworkHandler.setup();
+
+        DeferredWorkQueue.runLater( () -> {
+            registerProviders();
+            ArgumentSerializers.register();
+            registerLoot();
+        } );
+
+        ComputerCraftAPI.registerGenericSource( new InventoryMethods() );
+        ComputerCraftAPI.registerGenericSource( new FluidMethods() );
+        ComputerCraftAPI.registerGenericSource( new EnergyMethods() );
+    }
+
+    private static void registerProviders()
+    {
+        // Register bundled power providers
+        ComputerCraftAPI.registerBundledRedstoneProvider( new DefaultBundledRedstoneProvider() );
+
+        // Register media providers
+        ComputerCraftAPI.registerMediaProvider( stack -> {
+            Item item = stack.getItem();
+            if( item instanceof IMedia ) return (IMedia) item;
+            if( item instanceof MusicDiscItem ) return RecordMedia.INSTANCE;
+            return null;
+        } );
+
+        // Register capabilities
+        CapabilityManager.INSTANCE.register( IWiredElement.class, new NullStorage<>(), () -> null );
+        CapabilityManager.INSTANCE.register( IPeripheral.class, new NullStorage<>(), () -> null );
+
+        // Register generic capabilities. This can technically be done off-thread, but we need it to happen
+        // after Forge's common setup, so this is easiest.
+        ComputerCraftAPI.registerGenericCapability( CapabilityItemHandler.ITEM_HANDLER_CAPABILITY );
+        ComputerCraftAPI.registerGenericCapability( CapabilityEnergy.ENERGY );
+        ComputerCraftAPI.registerGenericCapability( CapabilityFluidHandler.FLUID_HANDLER_CAPABILITY );
+    }
+
+    public static void registerLoot()
+    {
+        LootConditionManager.register( ConstantLootConditionSerializer.of(
+            new ResourceLocation( ComputerCraft.MOD_ID, "block_named" ),
+            BlockNamedEntityLootCondition.class,
+            BlockNamedEntityLootCondition.INSTANCE
+        ) );
+
+        LootConditionManager.register( ConstantLootConditionSerializer.of(
+            new ResourceLocation( ComputerCraft.MOD_ID, "player_creative" ),
+            PlayerCreativeLootCondition.class,
+            PlayerCreativeLootCondition.INSTANCE
+        ) );
+
+        LootConditionManager.register( ConstantLootConditionSerializer.of(
+            new ResourceLocation( ComputerCraft.MOD_ID, "has_id" ),
+            HasComputerIdLootCondition.class,
+            HasComputerIdLootCondition.INSTANCE
+        ) );
+    }
+
     public static void setup()
     {
         IEventBus bus = FMLJavaModLoadingContext.get().getModEventBus();

src/main/java/dan200/computercraft/shared/TurtleUpgrades.java

@@ -33,9 +33,9 @@ public final class TurtleUpgrades
         Wrapper( ITurtleUpgrade upgrade )
         {
             this.upgrade = upgrade;
-            this.id = upgrade.getUpgradeID().toString();
-            this.modId = ModLoadingContext.get().getActiveNamespace();
-            this.enabled = true;
+            id = upgrade.getUpgradeID().toString();
+            modId = ModLoadingContext.get().getActiveNamespace();
+            enabled = true;
         }
     }
 

src/main/java/dan200/computercraft/shared/command/ClientCommands.java

@@ -0,0 +1,58 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.shared.command;
+
+import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.shared.util.IDAssigner;
+import net.minecraft.util.Util;
+import net.minecraftforge.api.distmarker.Dist;
+import net.minecraftforge.client.event.ClientChatEvent;
+import net.minecraftforge.eventbus.api.SubscribeEvent;
+import net.minecraftforge.fml.common.Mod;
+
+import java.io.File;
+
+/**
+ * Basic client-side commands.
+ *
+ * Simply hooks into client chat messages and intercepts matching strings.
+ */
+@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Dist.CLIENT )
+public final class ClientCommands
+{
+    public static final String OPEN_COMPUTER = "/computercraft open-computer ";
+
+    private ClientCommands()
+    {
+    }
+
+    @SubscribeEvent
+    public static void onClientSendMessage( ClientChatEvent event )
+    {
+        // Emulate the command on the client side
+        if( event.getMessage().startsWith( OPEN_COMPUTER ) )
+        {
+            event.setCanceled( true );
+
+            String idStr = event.getMessage().substring( OPEN_COMPUTER.length() ).trim();
+            int id;
+            try
+            {
+                id = Integer.parseInt( idStr );
+            }
+            catch( NumberFormatException ignore )
+            {
+                return;
+            }
+
+            File file = new File( IDAssigner.getDir(), "computer/" + id );
+            if( !file.isDirectory() ) return;
+
+            Util.getPlatform().openFile( file );
+        }
+    }
+
+}

src/main/java/dan200/computercraft/shared/command/CommandComputerCraft.java

@@ -21,6 +21,7 @@ import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.computer.core.ServerComputer;
 import dan200.computercraft.shared.computer.inventory.ContainerViewComputer;
 import dan200.computercraft.shared.network.container.ViewComputerContainerData;
+import dan200.computercraft.shared.util.IDAssigner;
 import net.minecraft.command.CommandSource;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.player.PlayerEntity;
@@ -37,6 +38,7 @@ import net.minecraft.world.World;
 import net.minecraft.world.server.ServerWorld;
 
 import javax.annotation.Nonnull;
+import java.io.File;
 import java.util.*;
 
 import static dan200.computercraft.shared.command.CommandUtils.isPlayer;
@@ -320,6 +322,12 @@ public final class CommandComputerCraft
                 ) );
         }
 
+        if( UserLevel.OWNER.test( source ) && isPlayer( source ) )
+        {
+            ITextComponent linkPath = linkStorage( computerId );
+            if( linkPath != null ) out.append( " " ).append( linkPath );
+        }
+
         return out;
     }
 
@@ -339,6 +347,18 @@ public final class CommandComputerCraft
         }
     }
 
+    private static ITextComponent linkStorage( int id )
+    {
+        File file = new File( IDAssigner.getDir(), "computer/" + id );
+        if( !file.isDirectory() ) return null;
+
+        return link(
+            text( "\u270E" ),
+            ClientCommands.OPEN_COMPUTER + id,
+            translate( "commands.computercraft.dump.open_path" )
+        );
+    }
+
     @Nonnull
     private static TrackingContext getTimingContext( CommandSource source )
     {

src/main/java/dan200/computercraft/shared/command/CommandCopy.java

@@ -1,66 +0,0 @@
-/*
- * This file is part of ComputerCraft - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
- * Send enquiries to dratcliffe@gmail.com
- */
-package dan200.computercraft.shared.command;
-
-import com.mojang.brigadier.CommandDispatcher;
-import com.mojang.brigadier.arguments.StringArgumentType;
-import dan200.computercraft.ComputerCraft;
-import net.minecraft.client.Minecraft;
-import net.minecraft.command.CommandSource;
-import net.minecraft.util.text.ITextComponent;
-import net.minecraft.util.text.StringTextComponent;
-import net.minecraft.util.text.TranslationTextComponent;
-import net.minecraft.util.text.event.ClickEvent;
-import net.minecraft.util.text.event.HoverEvent;
-import net.minecraftforge.api.distmarker.Dist;
-import net.minecraftforge.client.event.ClientChatEvent;
-import net.minecraftforge.eventbus.api.SubscribeEvent;
-import net.minecraftforge.fml.common.Mod;
-
-import static net.minecraft.command.Commands.argument;
-import static net.minecraft.command.Commands.literal;
-
-@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Dist.CLIENT )
-public final class CommandCopy
-{
-    private static final String PREFIX = "/computercraft copy ";
-
-    private CommandCopy()
-    {
-    }
-
-    public static void register( CommandDispatcher<CommandSource> registry )
-    {
-        registry.register( literal( "computercraft" )
-            .then( literal( "copy" ) )
-            .then( argument( "message", StringArgumentType.greedyString() ) )
-            .executes( context -> {
-                Minecraft.getInstance().keyboardHandler.setClipboard( context.getArgument( "message", String.class ) );
-                return 1;
-            } )
-        );
-    }
-
-    @SubscribeEvent
-    public static void onClientSendMessage( ClientChatEvent event )
-    {
-        // Emulate the command on the client side
-        if( event.getMessage().startsWith( PREFIX ) )
-        {
-            Minecraft.getInstance().keyboardHandler.setClipboard( event.getMessage().substring( PREFIX.length() ) );
-            event.setCanceled( true );
-        }
-    }
-
-    public static ITextComponent createCopyText( String text )
-    {
-        StringTextComponent name = new StringTextComponent( text );
-        name.getStyle()
-            .setClickEvent( new ClickEvent( ClickEvent.Action.RUN_COMMAND, PREFIX + text ) )
-            .setHoverEvent( new HoverEvent( HoverEvent.Action.SHOW_TEXT, new TranslationTextComponent( "gui.computercraft.tooltip.copy" ) ) );
-        return name;
-    }
-}

src/main/java/dan200/computercraft/shared/command/UserLevel.java

@@ -57,14 +57,15 @@ public enum UserLevel implements Predicate<CommandSource>
     {
         if( this == ANYONE ) return true;
 
-        // We *always* allow level 0 stuff, even if the
-        MinecraftServer server = source.getServer();
-        Entity sender = source.getEntity();
-
-        if( server.isSingleplayer() && sender instanceof PlayerEntity &&
-            ((PlayerEntity) sender).getGameProfile().getName().equalsIgnoreCase( server.getServerModName() ) )
+        if( this == OWNER || this == OWNER_OP )
         {
-            if( this == OWNER || this == OWNER_OP ) return true;
+            MinecraftServer server = source.getServer();
+            Entity sender = source.getEntity();
+            if( server.isSingleplayer() && sender instanceof PlayerEntity &&
+                ((PlayerEntity) sender).getGameProfile().getName().equalsIgnoreCase( server.getServerModName() ) )
+            {
+                return true;
+            }
         }
 
         return source.hasPermission( toLevel() );

src/main/java/dan200/computercraft/shared/command/text/ChatHelpers.java

@@ -71,11 +71,16 @@ public final class ChatHelpers
     }
 
     public static ITextComponent link( ITextComponent component, String command, ITextComponent toolTip )
+    {
+        return link( component, new ClickEvent( ClickEvent.Action.RUN_COMMAND, command ), toolTip );
+    }
+
+    public static ITextComponent link( ITextComponent component, ClickEvent click, ITextComponent toolTip )
     {
         Style style = component.getStyle();
 
         if( style.getColor() == null ) style.setColor( TextFormatting.YELLOW );
-        style.setClickEvent( new ClickEvent( ClickEvent.Action.RUN_COMMAND, command ) );
+        style.setClickEvent( click );
         style.setHoverEvent( new HoverEvent( HoverEvent.Action.SHOW_TEXT, toolTip ) );
 
         return component;
@@ -85,4 +90,13 @@ public final class ChatHelpers
     {
         return coloured( text, HEADER );
     }
+
+    public static ITextComponent copy( String text )
+    {
+        StringTextComponent name = new StringTextComponent( text );
+        name.getStyle()
+            .setClickEvent( new ClickEvent( ClickEvent.Action.COPY_TO_CLIPBOARD, text ) )
+            .setHoverEvent( new HoverEvent( HoverEvent.Action.SHOW_TEXT, new TranslationTextComponent( "gui.computercraft.tooltip.copy" ) ) );
+        return name;
+    }
 }

src/main/java/dan200/computercraft/shared/common/ContainerHeldItem.java

@@ -61,7 +61,7 @@ public class ContainerHeldItem extends Container
         public Factory( ContainerType<ContainerHeldItem> type, ItemStack stack, Hand hand )
         {
             this.type = type;
-            this.name = stack.getHoverName();
+            name = stack.getHoverName();
             this.hand = hand;
         }
 

src/main/java/dan200/computercraft/shared/computer/blocks/TileCommandComputer.java

@@ -56,7 +56,7 @@ public class TileCommandComputer extends TileComputer
         @Override
         public boolean acceptsSuccess()
         {
-            return getLevel().getGameRules().getBoolean( GameRules.RULE_SENDCOMMANDFEEDBACK );
+            return true;
         }
 
         @Override

src/main/java/dan200/computercraft/shared/computer/blocks/TileComputerBase.java

@@ -175,12 +175,12 @@ public abstract class TileComputerBase extends TileGeneric implements IComputerT
             label = computer.getLabel();
             on = computer.isOn();
 
-            if( computer.hasOutputChanged() ) updateOutput();
-
             // Update the block state if needed. We don't fire a block update intentionally,
             // as this only really is needed on the client side.
             updateBlockState( computer.getState() );
 
+            // TODO: This should ideally be split up into label/id/on (which should save NBT and sync to client) and
+            //  redstone (which should update outputs)
             if( computer.hasOutputChanged() ) updateOutput();
         }
     }
@@ -376,11 +376,8 @@ public abstract class TileComputerBase extends TileGeneric implements IComputerT
             fresh = true;
             changed = true;
         }
-        if( changed )
-        {
-            updateBlock();
-            updateInput();
-        }
+
+        if( changed ) updateInput();
         return ComputerCraft.serverComputerRegistry.get( instanceID );
     }
 

src/main/java/dan200/computercraft/shared/computer/inventory/ContainerViewComputer.java

@@ -25,14 +25,14 @@ public class ContainerViewComputer extends ContainerComputerBase implements ICon
     public ContainerViewComputer( int id, ServerComputer computer )
     {
         super( Registry.ModContainers.VIEW_COMPUTER.get(), id, player -> canInteractWith( computer, player ), computer, computer.getFamily() );
-        this.width = this.height = 0;
+        width = height = 0;
     }
 
     public ContainerViewComputer( int id, PlayerInventory player, ViewComputerContainerData data )
     {
         super( Registry.ModContainers.VIEW_COMPUTER.get(), id, player, data );
-        this.width = data.getWidth();
-        this.height = data.getHeight();
+        width = data.getWidth();
+        height = data.getHeight();
     }
 
     private static boolean canInteractWith( @Nonnull ServerComputer computer, @Nonnull PlayerEntity player )

src/main/java/dan200/computercraft/shared/integration/crafttweaker/actions/AddTurtleTool.java

@@ -99,6 +99,7 @@ public class AddTurtleTool implements IUndoableAction
         return String.format( "Removing turtle upgrade %s.", id );
     }
 
+    @Override
     public boolean validate( ILogger logger )
     {
         TrackingLogger trackLog = new TrackingLogger( logger );

src/main/java/dan200/computercraft/shared/integration/crafttweaker/actions/RemoveTurtleUpgradeByItem.java

@@ -41,7 +41,7 @@ public class RemoveTurtleUpgradeByItem implements IUndoableAction
     @Override
     public void undo()
     {
-        if( this.upgrade != null ) TurtleUpgrades.enable( upgrade );
+        if( upgrade != null ) TurtleUpgrades.enable( upgrade );
     }
 
     @Override

src/main/java/dan200/computercraft/shared/integration/crafttweaker/actions/RemoveTurtleUpgradeByName.java

@@ -40,7 +40,7 @@ public class RemoveTurtleUpgradeByName implements IUndoableAction
     @Override
     public void undo()
     {
-        if( this.upgrade != null ) TurtleUpgrades.enable( upgrade );
+        if( upgrade != null ) TurtleUpgrades.enable( upgrade );
     }
 
     @Override

src/main/java/dan200/computercraft/shared/integration/jei/RecipeResolver.java

@@ -339,17 +339,17 @@ class RecipeResolver implements IRecipeManagerPlugin
         UpgradeInfo( ItemStack stack, ITurtleUpgrade turtle )
         {
             this.stack = stack;
-            this.ingredient = of( stack );
-            this.upgrade = this.turtle = turtle;
-            this.pocket = null;
+            ingredient = of( stack );
+            upgrade = this.turtle = turtle;
+            pocket = null;
         }
 
         UpgradeInfo( ItemStack stack, IPocketUpgrade pocket )
         {
             this.stack = stack;
-            this.ingredient = of( stack );
-            this.turtle = null;
-            this.upgrade = this.pocket = pocket;
+            ingredient = of( stack );
+            turtle = null;
+            upgrade = this.pocket = pocket;
         }
 
         List<Shaped> getRecipes()

src/main/java/dan200/computercraft/shared/media/items/ItemTreasureDisk.java

@@ -68,6 +68,8 @@ public class ItemTreasureDisk extends Item implements IMedia
     public IMount createDataMount( @Nonnull ItemStack stack, @Nonnull World world )
     {
         IMount rootTreasure = getTreasureMount();
+        if( rootTreasure == null ) return null;
+
         String subPath = getSubPath( stack );
         try
         {
@@ -121,7 +123,7 @@ public class ItemTreasureDisk extends Item implements IMedia
     private static String getTitle( @Nonnull ItemStack stack )
     {
         CompoundNBT nbt = stack.getTag();
-        return nbt != null && nbt.contains( NBT_TITLE ) ? nbt.getString( NBT_TITLE ) : "'alongtimeago' by dan200";
+        return nbt != null && nbt.contains( NBT_TITLE ) ? nbt.getString( NBT_TITLE ) : "'missingno' by how did you get this anyway?";
     }
 
     @Nonnull

src/main/java/dan200/computercraft/shared/network/NetworkHandler.java

@@ -43,19 +43,22 @@ public final class NetworkHandler
             .simpleChannel();
 
         // Server messages
-        registerMainThread( 0, NetworkDirection.PLAY_TO_SERVER, ComputerActionServerMessage::new );
-        registerMainThread( 1, NetworkDirection.PLAY_TO_SERVER, QueueEventServerMessage::new );
-        registerMainThread( 2, NetworkDirection.PLAY_TO_SERVER, RequestComputerMessage::new );
-        registerMainThread( 3, NetworkDirection.PLAY_TO_SERVER, KeyEventServerMessage::new );
-        registerMainThread( 4, NetworkDirection.PLAY_TO_SERVER, MouseEventServerMessage::new );
+        registerMainThread( 0, NetworkDirection.PLAY_TO_SERVER, ComputerActionServerMessage.class, ComputerActionServerMessage::new );
+        registerMainThread( 1, NetworkDirection.PLAY_TO_SERVER, QueueEventServerMessage.class, QueueEventServerMessage::new );
+        registerMainThread( 2, NetworkDirection.PLAY_TO_SERVER, RequestComputerMessage.class, RequestComputerMessage::new );
+        registerMainThread( 3, NetworkDirection.PLAY_TO_SERVER, KeyEventServerMessage.class, KeyEventServerMessage::new );
+        registerMainThread( 4, NetworkDirection.PLAY_TO_SERVER, MouseEventServerMessage.class, MouseEventServerMessage::new );
 
         // Client messages
-        registerMainThread( 10, NetworkDirection.PLAY_TO_CLIENT, ChatTableClientMessage::new );
-        registerMainThread( 11, NetworkDirection.PLAY_TO_CLIENT, ComputerDataClientMessage::new );
-        registerMainThread( 12, NetworkDirection.PLAY_TO_CLIENT, ComputerDeletedClientMessage::new );
-        registerMainThread( 13, NetworkDirection.PLAY_TO_CLIENT, ComputerTerminalClientMessage::new );
+        registerMainThread( 10, NetworkDirection.PLAY_TO_CLIENT, ChatTableClientMessage.class, ChatTableClientMessage::new );
+        registerMainThread( 11, NetworkDirection.PLAY_TO_CLIENT, ComputerDataClientMessage.class, ComputerDataClientMessage::new );
+        registerMainThread( 12, NetworkDirection.PLAY_TO_CLIENT, ComputerDeletedClientMessage.class, ComputerDeletedClientMessage::new );
+        registerMainThread( 13, NetworkDirection.PLAY_TO_CLIENT, ComputerTerminalClientMessage.class, ComputerTerminalClientMessage::new );
         registerMainThread( 14, NetworkDirection.PLAY_TO_CLIENT, PlayRecordClientMessage.class, PlayRecordClientMessage::new );
         registerMainThread( 15, NetworkDirection.PLAY_TO_CLIENT, MonitorClientMessage.class, MonitorClientMessage::new );
+        registerMainThread( 16, NetworkDirection.PLAY_TO_CLIENT, SpeakerPlayClientMessage.class, SpeakerPlayClientMessage::new );
+        registerMainThread( 17, NetworkDirection.PLAY_TO_CLIENT, SpeakerStopClientMessage.class, SpeakerStopClientMessage::new );
+        registerMainThread( 18, NetworkDirection.PLAY_TO_CLIENT, SpeakerMoveClientMessage.class, SpeakerMoveClientMessage::new );
     }
 
     public static void sendToPlayer( PlayerEntity player, NetworkMessage packet )
@@ -87,24 +90,6 @@ public final class NetworkHandler
         network.send( PacketDistributor.TRACKING_CHUNK.with( () -> chunk ), packet );
     }
 
-    /**
-     * /**
-     * Register packet, and a thread-unsafe handler for it.
-     *
-     * @param <T>       The type of the packet to send.
-     * @param id        The identifier for this packet type.
-     * @param direction A network direction which will be asserted before any processing of this message occurs.
-     * @param factory   The factory for this type of packet.
-     */
-    private static <T extends NetworkMessage> void registerMainThread( int id, NetworkDirection direction, Supplier<T> factory )
-    {
-        registerMainThread( id, direction, getType( factory ), buf -> {
-            T instance = factory.get();
-            instance.fromBytes( buf );
-            return instance;
-        } );
-    }
-
     /**
      * /**
      * Register packet, and a thread-unsafe handler for it.

src/main/java/dan200/computercraft/shared/network/NetworkMessage.java

@@ -27,18 +27,6 @@ public interface NetworkMessage
      */
     void toBytes( @Nonnull PacketBuffer buf );
 
-    /**
-     * Read this packet from a buffer.
-     *
-     * This may be called on any thread, so this should be a pure operation.
-     *
-     * @param buf The buffer to read data from.
-     */
-    default void fromBytes( @Nonnull PacketBuffer buf )
-    {
-        throw new IllegalStateException( "Should have been registered using a \"from bytes\" method" );
-    }
-
     /**
      * Handle this {@link NetworkMessage}.
      *

src/main/java/dan200/computercraft/shared/network/client/ChatTableClientMessage.java

@@ -16,7 +16,7 @@ import javax.annotation.Nonnull;
 
 public class ChatTableClientMessage implements NetworkMessage
 {
-    private TableBuilder table;
+    private final TableBuilder table;
 
     public ChatTableClientMessage( TableBuilder table )
     {
@@ -24,32 +24,7 @@ public class ChatTableClientMessage implements NetworkMessage
         this.table = table;
     }
 
-    public ChatTableClientMessage()
-    {
-    }
-
-    @Override
-    public void toBytes( @Nonnull PacketBuffer buf )
-    {
-        buf.writeVarInt( table.getId() );
-        buf.writeVarInt( table.getColumns() );
-        buf.writeBoolean( table.getHeaders() != null );
-        if( table.getHeaders() != null )
-        {
-            for( ITextComponent header : table.getHeaders() ) buf.writeComponent( header );
-        }
-
-        buf.writeVarInt( table.getRows().size() );
-        for( ITextComponent[] row : table.getRows() )
-        {
-            for( ITextComponent column : row ) buf.writeComponent( column );
-        }
-
-        buf.writeVarInt( table.getAdditional() );
-    }
-
-    @Override
-    public void fromBytes( @Nonnull PacketBuffer buf )
+    public ChatTableClientMessage( @Nonnull PacketBuffer buf )
     {
         int id = buf.readVarInt();
         int columns = buf.readVarInt();
@@ -77,6 +52,26 @@ public class ChatTableClientMessage implements NetworkMessage
         this.table = table;
     }
 
+    @Override
+    public void toBytes( @Nonnull PacketBuffer buf )
+    {
+        buf.writeVarInt( table.getId() );
+        buf.writeVarInt( table.getColumns() );
+        buf.writeBoolean( table.getHeaders() != null );
+        if( table.getHeaders() != null )
+        {
+            for( ITextComponent header : table.getHeaders() ) buf.writeComponent( header );
+        }
+
+        buf.writeVarInt( table.getRows().size() );
+        for( ITextComponent[] row : table.getRows() )
+        {
+            for( ITextComponent column : row ) buf.writeComponent( column );
+        }
+
+        buf.writeVarInt( table.getAdditional() );
+    }
+
     @Override
     public void handle( NetworkEvent.Context context )
     {

src/main/java/dan200/computercraft/shared/network/client/ComputerClientMessage.java

@@ -17,15 +17,16 @@ import javax.annotation.Nonnull;
  */
 public abstract class ComputerClientMessage implements NetworkMessage
 {
-    private int instanceId;
+    private final int instanceId;
 
     public ComputerClientMessage( int instanceId )
     {
         this.instanceId = instanceId;
     }
 
-    public ComputerClientMessage()
+    public ComputerClientMessage( @Nonnull PacketBuffer buf )
     {
+        instanceId = buf.readVarInt();
     }
 
     public int getInstanceId()
@@ -39,12 +40,6 @@ public abstract class ComputerClientMessage implements NetworkMessage
         buf.writeVarInt( instanceId );
     }
 
-    @Override
-    public void fromBytes( @Nonnull PacketBuffer buf )
-    {
-        instanceId = buf.readVarInt();
-    }
-
     public ClientComputer getComputer()
     {
         ClientComputer computer = ComputerCraft.clientComputerRegistry.get( instanceId );

src/main/java/dan200/computercraft/shared/network/client/ComputerDataClientMessage.java

@@ -18,8 +18,8 @@ import javax.annotation.Nonnull;
  */
 public class ComputerDataClientMessage extends ComputerClientMessage
 {
-    private ComputerState state;
-    private CompoundNBT userData;
+    private final ComputerState state;
+    private final CompoundNBT userData;
 
     public ComputerDataClientMessage( ServerComputer computer )
     {
@@ -28,8 +28,11 @@ public class ComputerDataClientMessage extends ComputerClientMessage
         userData = computer.getUserData();
     }
 
-    public ComputerDataClientMessage()
+    public ComputerDataClientMessage( @Nonnull PacketBuffer buf )
     {
+        super( buf );
+        state = buf.readEnum( ComputerState.class );
+        userData = buf.readNbt();
     }
 
     @Override
@@ -40,14 +43,6 @@ public class ComputerDataClientMessage extends ComputerClientMessage
         buf.writeNbt( userData );
     }
 
-    @Override
-    public void fromBytes( @Nonnull PacketBuffer buf )
-    {
-        super.fromBytes( buf );
-        state = buf.readEnum( ComputerState.class );
-        userData = buf.readNbt();
-    }
-
     @Override
     public void handle( NetworkEvent.Context context )
     {

src/main/java/dan200/computercraft/shared/network/client/ComputerDeletedClientMessage.java

@@ -6,6 +6,7 @@
 package dan200.computercraft.shared.network.client;
 
 import dan200.computercraft.ComputerCraft;
+import net.minecraft.network.PacketBuffer;
 import net.minecraftforge.fml.network.NetworkEvent;
 
 public class ComputerDeletedClientMessage extends ComputerClientMessage
@@ -15,8 +16,9 @@ public class ComputerDeletedClientMessage extends ComputerClientMessage
         super( instanceId );
     }
 
-    public ComputerDeletedClientMessage()
+    public ComputerDeletedClientMessage( PacketBuffer buffer )
     {
+        super( buffer );
     }
 
     @Override

src/main/java/dan200/computercraft/shared/network/client/ComputerTerminalClientMessage.java

@@ -12,7 +12,7 @@ import javax.annotation.Nonnull;
 
 public class ComputerTerminalClientMessage extends ComputerClientMessage
 {
-    private TerminalState state;
+    private final TerminalState state;
 
     public ComputerTerminalClientMessage( int instanceId, TerminalState state )
     {
@@ -20,8 +20,10 @@ public class ComputerTerminalClientMessage extends ComputerClientMessage
         this.state = state;
     }
 
-    public ComputerTerminalClientMessage()
+    public ComputerTerminalClientMessage( @Nonnull PacketBuffer buf )
     {
+        super( buf );
+        state = new TerminalState( buf );
     }
 
     @Override
@@ -31,13 +33,6 @@ public class ComputerTerminalClientMessage extends ComputerClientMessage
         state.write( buf );
     }
 
-    @Override
-    public void fromBytes( @Nonnull PacketBuffer buf )
-    {
-        super.fromBytes( buf );
-        state = new TerminalState( buf );
-    }
-
     @Override
     public void handle( NetworkEvent.Context context )
     {

src/main/java/dan200/computercraft/shared/network/client/SpeakerMoveClientMessage.java

@@ -0,0 +1,58 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.shared.network.client;
+
+import dan200.computercraft.client.SoundManager;
+import dan200.computercraft.shared.network.NetworkMessage;
+import net.minecraft.network.PacketBuffer;
+import net.minecraft.util.math.Vec3d;
+import net.minecraftforge.api.distmarker.Dist;
+import net.minecraftforge.api.distmarker.OnlyIn;
+import net.minecraftforge.fml.network.NetworkEvent;
+
+import javax.annotation.Nonnull;
+import java.util.UUID;
+
+/**
+ * Starts a sound on the client.
+ *
+ * Used by speakers to play sounds.
+ *
+ * @see dan200.computercraft.shared.peripheral.speaker.TileSpeaker
+ */
+public class SpeakerMoveClientMessage implements NetworkMessage
+{
+    private final UUID source;
+    private final Vec3d pos;
+
+    public SpeakerMoveClientMessage( UUID source, Vec3d pos )
+    {
+        this.source = source;
+        this.pos = pos;
+    }
+
+    public SpeakerMoveClientMessage( PacketBuffer buf )
+    {
+        source = buf.readUUID();
+        pos = new Vec3d( buf.readDouble(), buf.readDouble(), buf.readDouble() );
+    }
+
+    @Override
+    public void toBytes( @Nonnull PacketBuffer buf )
+    {
+        buf.writeUUID( source );
+        buf.writeDouble( pos.x() );
+        buf.writeDouble( pos.y() );
+        buf.writeDouble( pos.z() );
+    }
+
+    @Override
+    @OnlyIn( Dist.CLIENT )
+    public void handle( NetworkEvent.Context context )
+    {
+        SoundManager.moveSound( source, pos );
+    }
+}

src/main/java/dan200/computercraft/shared/network/client/SpeakerPlayClientMessage.java

@@ -0,0 +1,74 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.shared.network.client;
+
+import dan200.computercraft.client.SoundManager;
+import dan200.computercraft.shared.network.NetworkMessage;
+import net.minecraft.network.PacketBuffer;
+import net.minecraft.util.ResourceLocation;
+import net.minecraft.util.SoundEvent;
+import net.minecraft.util.math.Vec3d;
+import net.minecraftforge.api.distmarker.Dist;
+import net.minecraftforge.api.distmarker.OnlyIn;
+import net.minecraftforge.fml.network.NetworkEvent;
+import net.minecraftforge.registries.ForgeRegistries;
+
+import javax.annotation.Nonnull;
+import java.util.UUID;
+
+/**
+ * Starts a sound on the client.
+ *
+ * Used by speakers to play sounds.
+ *
+ * @see dan200.computercraft.shared.peripheral.speaker.TileSpeaker
+ */
+public class SpeakerPlayClientMessage implements NetworkMessage
+{
+    private final UUID source;
+    private final Vec3d pos;
+    private final ResourceLocation sound;
+    private final float volume;
+    private final float pitch;
+
+    public SpeakerPlayClientMessage( UUID source, Vec3d pos, ResourceLocation event, float volume, float pitch )
+    {
+        this.source = source;
+        this.pos = pos;
+        sound = event;
+        this.volume = volume;
+        this.pitch = pitch;
+    }
+
+    public SpeakerPlayClientMessage( PacketBuffer buf )
+    {
+        source = buf.readUUID();
+        pos = new Vec3d( buf.readDouble(), buf.readDouble(), buf.readDouble() );
+        sound = buf.readResourceLocation();
+        volume = buf.readFloat();
+        pitch = buf.readFloat();
+    }
+
+    @Override
+    public void toBytes( @Nonnull PacketBuffer buf )
+    {
+        buf.writeUUID( source );
+        buf.writeDouble( pos.x() );
+        buf.writeDouble( pos.y() );
+        buf.writeDouble( pos.z() );
+        buf.writeResourceLocation( sound );
+        buf.writeFloat( volume );
+        buf.writeFloat( pitch );
+    }
+
+    @Override
+    @OnlyIn( Dist.CLIENT )
+    public void handle( NetworkEvent.Context context )
+    {
+        SoundEvent sound = ForgeRegistries.SOUND_EVENTS.getValue( this.sound );
+        if( sound != null ) SoundManager.playSound( source, pos, sound, volume, pitch );
+    }
+}

src/main/java/dan200/computercraft/shared/network/client/SpeakerStopClientMessage.java

@@ -0,0 +1,51 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.shared.network.client;
+
+import dan200.computercraft.client.SoundManager;
+import dan200.computercraft.shared.network.NetworkMessage;
+import net.minecraft.network.PacketBuffer;
+import net.minecraftforge.api.distmarker.Dist;
+import net.minecraftforge.api.distmarker.OnlyIn;
+import net.minecraftforge.fml.network.NetworkEvent;
+
+import javax.annotation.Nonnull;
+import java.util.UUID;
+
+/**
+ * Stops a sound on the client
+ *
+ * Called when a speaker is broken.
+ *
+ * @see dan200.computercraft.shared.peripheral.speaker.TileSpeaker
+ */
+public class SpeakerStopClientMessage implements NetworkMessage
+{
+    private final UUID source;
+
+    public SpeakerStopClientMessage( UUID source )
+    {
+        this.source = source;
+    }
+
+    public SpeakerStopClientMessage( PacketBuffer buf )
+    {
+        source = buf.readUUID();
+    }
+
+    @Override
+    public void toBytes( @Nonnull PacketBuffer buf )
+    {
+        buf.writeUUID( source );
+    }
+
+    @Override
+    @OnlyIn( Dist.CLIENT )
+    public void handle( NetworkEvent.Context context )
+    {
+        SoundManager.stopSound( source );
+    }
+}

src/main/java/dan200/computercraft/shared/network/client/TerminalState.java

@@ -54,36 +54,36 @@ public class TerminalState
 
         if( terminal == null )
         {
-            this.width = this.height = 0;
-            this.buffer = null;
+            width = height = 0;
+            buffer = null;
         }
         else
         {
-            this.width = terminal.getWidth();
-            this.height = terminal.getHeight();
+            width = terminal.getWidth();
+            height = terminal.getHeight();
 
-            ByteBuf buf = this.buffer = Unpooled.buffer();
+            ByteBuf buf = buffer = Unpooled.buffer();
             terminal.write( new PacketBuffer( buf ) );
         }
     }
 
     public TerminalState( PacketBuffer buf )
     {
-        this.colour = buf.readBoolean();
-        this.compress = buf.readBoolean();
+        colour = buf.readBoolean();
+        compress = buf.readBoolean();
 
         if( buf.readBoolean() )
         {
-            this.width = buf.readVarInt();
-            this.height = buf.readVarInt();
+            width = buf.readVarInt();
+            height = buf.readVarInt();
 
             int length = buf.readVarInt();
-            this.buffer = readCompressed( buf, length, compress );
+            buffer = readCompressed( buf, length, compress );
         }
         else
         {
-            this.width = this.height = 0;
-            this.buffer = null;
+            width = height = 0;
+            buffer = null;
         }
     }
 

src/main/java/dan200/computercraft/shared/network/container/ComputerContainerData.java

@@ -16,14 +16,14 @@ public class ComputerContainerData implements ContainerData
 
     public ComputerContainerData( ServerComputer computer )
     {
-        this.id = computer.getInstanceID();
-        this.family = computer.getFamily();
+        id = computer.getInstanceID();
+        family = computer.getFamily();
     }
 
     public ComputerContainerData( PacketBuffer buf )
     {
-        this.id = buf.readInt();
-        this.family = buf.readEnum( ComputerFamily.class );
+        id = buf.readInt();
+        family = buf.readEnum( ComputerFamily.class );
     }
 
     @Override

src/main/java/dan200/computercraft/shared/network/server/ComputerActionServerMessage.java

@@ -13,7 +13,7 @@ import javax.annotation.Nonnull;
 
 public class ComputerActionServerMessage extends ComputerServerMessage
 {
-    private Action action;
+    private final Action action;
 
     public ComputerActionServerMessage( int instanceId, Action action )
     {
@@ -21,8 +21,10 @@ public class ComputerActionServerMessage extends ComputerServerMessage
         this.action = action;
     }
 
-    public ComputerActionServerMessage()
+    public ComputerActionServerMessage( @Nonnull PacketBuffer buf )
     {
+        super( buf );
+        action = buf.readEnum( Action.class );
     }
 
     @Override
@@ -32,13 +34,6 @@ public class ComputerActionServerMessage extends ComputerServerMessage
         buf.writeEnum( action );
     }
 
-    @Override
-    public void fromBytes( @Nonnull PacketBuffer buf )
-    {
-        super.fromBytes( buf );
-        action = buf.readEnum( Action.class );
-    }
-
     @Override
     protected void handle( @Nonnull ServerComputer computer, @Nonnull IContainerComputer container )
     {

src/main/java/dan200/computercraft/shared/network/server/ComputerServerMessage.java

@@ -22,15 +22,16 @@ import javax.annotation.Nonnull;
  */
 public abstract class ComputerServerMessage implements NetworkMessage
 {
-    private int instanceId;
+    private final int instanceId;
 
     public ComputerServerMessage( int instanceId )
     {
         this.instanceId = instanceId;
     }
 
-    public ComputerServerMessage()
+    public ComputerServerMessage( @Nonnull PacketBuffer buf )
     {
+        instanceId = buf.readVarInt();
     }
 
     @Override
@@ -39,12 +40,6 @@ public abstract class ComputerServerMessage implements NetworkMessage
         buf.writeVarInt( instanceId );
     }
 
-    @Override
-    public void fromBytes( @Nonnull PacketBuffer buf )
-    {
-        instanceId = buf.readVarInt();
-    }
-
     @Override
     public void handle( NetworkEvent.Context context )
     {

src/main/java/dan200/computercraft/shared/network/server/KeyEventServerMessage.java

@@ -18,8 +18,8 @@ public class KeyEventServerMessage extends ComputerServerMessage
     public static final int TYPE_REPEAT = 1;
     public static final int TYPE_UP = 2;
 
-    private int type;
-    private int key;
+    private final int type;
+    private final int key;
 
     public KeyEventServerMessage( int instanceId, int type, int key )
     {
@@ -28,8 +28,11 @@ public class KeyEventServerMessage extends ComputerServerMessage
         this.key = key;
     }
 
-    public KeyEventServerMessage()
+    public KeyEventServerMessage( @Nonnull PacketBuffer buf )
     {
+        super( buf );
+        type = buf.readByte();
+        key = buf.readVarInt();
     }
 
     @Override
@@ -40,14 +43,6 @@ public class KeyEventServerMessage extends ComputerServerMessage
         buf.writeVarInt( key );
     }
 
-    @Override
-    public void fromBytes( @Nonnull PacketBuffer buf )
-    {
-        super.fromBytes( buf );
-        type = buf.readByte();
-        key = buf.readVarInt();
-    }
-
     @Override
     protected void handle( @Nonnull ServerComputer computer, @Nonnull IContainerComputer container )
     {

src/main/java/dan200/computercraft/shared/network/server/MouseEventServerMessage.java

@@ -19,10 +19,10 @@ public class MouseEventServerMessage extends ComputerServerMessage
     public static final int TYPE_UP = 2;
     public static final int TYPE_SCROLL = 3;
 
-    private int type;
-    private int x;
-    private int y;
-    private int arg;
+    private final int type;
+    private final int x;
+    private final int y;
+    private final int arg;
 
     public MouseEventServerMessage( int instanceId, int type, int arg, int x, int y )
     {
@@ -33,8 +33,13 @@ public class MouseEventServerMessage extends ComputerServerMessage
         this.y = y;
     }
 
-    public MouseEventServerMessage()
+    public MouseEventServerMessage( @Nonnull PacketBuffer buf )
     {
+        super( buf );
+        type = buf.readByte();
+        arg = buf.readVarInt();
+        x = buf.readVarInt();
+        y = buf.readVarInt();
     }
 
     @Override
@@ -47,16 +52,6 @@ public class MouseEventServerMessage extends ComputerServerMessage
         buf.writeVarInt( y );
     }
 
-    @Override
-    public void fromBytes( @Nonnull PacketBuffer buf )
-    {
-        super.fromBytes( buf );
-        type = buf.readByte();
-        arg = buf.readVarInt();
-        x = buf.readVarInt();
-        y = buf.readVarInt();
-    }
-
     @Override
     protected void handle( @Nonnull ServerComputer computer, @Nonnull IContainerComputer container )
     {

src/main/java/dan200/computercraft/shared/network/server/QueueEventServerMessage.java

@@ -22,8 +22,8 @@ import javax.annotation.Nullable;
  */
 public class QueueEventServerMessage extends ComputerServerMessage
 {
-    private String event;
-    private Object[] args;
+    private final String event;
+    private final Object[] args;
 
     public QueueEventServerMessage( int instanceId, @Nonnull String event, @Nullable Object[] args )
     {
@@ -32,8 +32,13 @@ public class QueueEventServerMessage extends ComputerServerMessage
         this.args = args;
     }
 
-    public QueueEventServerMessage()
+    public QueueEventServerMessage( @Nonnull PacketBuffer buf )
     {
+        super( buf );
+        event = buf.readUtf( Short.MAX_VALUE );
+
+        CompoundNBT args = buf.readNbt();
+        this.args = args == null ? null : NBTUtil.decodeObjects( args );
     }
 
     @Override
@@ -44,16 +49,6 @@ public class QueueEventServerMessage extends ComputerServerMessage
         buf.writeNbt( args == null ? null : NBTUtil.encodeObjects( args ) );
     }
 
-    @Override
-    public void fromBytes( @Nonnull PacketBuffer buf )
-    {
-        super.fromBytes( buf );
-        event = buf.readUtf( Short.MAX_VALUE );
-
-        CompoundNBT args = buf.readNbt();
-        this.args = args == null ? null : NBTUtil.decodeObjects( args );
-    }
-
     @Override
     protected void handle( @Nonnull ServerComputer computer, @Nonnull IContainerComputer container )
     {

src/main/java/dan200/computercraft/shared/network/server/RequestComputerMessage.java

@@ -15,15 +15,16 @@ import javax.annotation.Nonnull;
 
 public class RequestComputerMessage implements NetworkMessage
 {
-    private int instance;
+    private final int instance;
 
     public RequestComputerMessage( int instance )
     {
         this.instance = instance;
     }
 
-    public RequestComputerMessage()
+    public RequestComputerMessage( @Nonnull PacketBuffer buf )
     {
+        instance = buf.readVarInt();
     }
 
     @Override
@@ -32,12 +33,6 @@ public class RequestComputerMessage implements NetworkMessage
         buf.writeVarInt( instance );
     }
 
-    @Override
-    public void fromBytes( @Nonnull PacketBuffer buf )
-    {
-        instance = buf.readVarInt();
-    }
-
     @Override
     public void handle( NetworkEvent.Context context )
     {

src/main/java/dan200/computercraft/shared/peripheral/generic/SaturatedMethod.java

@@ -24,7 +24,7 @@ final class SaturatedMethod
     SaturatedMethod( Object target, NamedMethod<PeripheralMethod> method )
     {
         this.target = target;
-        this.name = method.getName();
+        name = method.getName();
         this.method = method.getMethod();
     }
 

src/main/java/dan200/computercraft/shared/peripheral/modem/wired/TileCable.java

@@ -11,7 +11,7 @@ import dan200.computercraft.api.network.wired.IWiredElement;
 import dan200.computercraft.api.network.wired.IWiredNode;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.shared.Registry;
-import dan200.computercraft.shared.command.CommandCopy;
+import dan200.computercraft.shared.command.text.ChatHelpers;
 import dan200.computercraft.shared.common.TileGeneric;
 import dan200.computercraft.shared.peripheral.modem.ModemState;
 import dan200.computercraft.shared.util.CapabilityUtil;
@@ -53,7 +53,7 @@ public class TileCable extends TileGeneric
         @Override
         public World getWorld()
         {
-            return TileCable.this.getLevel();
+            return getLevel();
         }
 
         @Nonnull
@@ -268,12 +268,12 @@ public class TileCable extends TileGeneric
             if( oldName != null )
             {
                 player.displayClientMessage( new TranslationTextComponent( "chat.computercraft.wired_modem.peripheral_disconnected",
-                    CommandCopy.createCopyText( oldName ) ), false );
+                    ChatHelpers.copy( oldName ) ), false );
             }
             if( newName != null )
             {
                 player.displayClientMessage( new TranslationTextComponent( "chat.computercraft.wired_modem.peripheral_connected",
-                    CommandCopy.createCopyText( newName ) ), false );
+                    ChatHelpers.copy( newName ) ), false );
             }
         }
 

src/main/java/dan200/computercraft/shared/peripheral/modem/wired/TileWiredModemFull.java

@@ -10,7 +10,7 @@ import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.api.network.wired.IWiredElement;
 import dan200.computercraft.api.network.wired.IWiredNode;
 import dan200.computercraft.api.peripheral.IPeripheral;
-import dan200.computercraft.shared.command.CommandCopy;
+import dan200.computercraft.shared.command.text.ChatHelpers;
 import dan200.computercraft.shared.common.TileGeneric;
 import dan200.computercraft.shared.peripheral.modem.ModemState;
 import dan200.computercraft.shared.util.CapabilityUtil;
@@ -218,7 +218,7 @@ public class TileWiredModemFull extends TileGeneric
         for( int i = 0; i < names.size(); i++ )
         {
             if( i > 0 ) base.append( ", " );
-            base.append( CommandCopy.createCopyText( names.get( i ) ) );
+            base.append( ChatHelpers.copy( names.get( i ) ) );
         }
 
         player.displayClientMessage( new TranslationTextComponent( kind, base ), false );

src/main/java/dan200/computercraft/shared/peripheral/monitor/BlockMonitor.java

@@ -87,7 +87,7 @@ public class BlockMonitor extends BlockGeneric
         {
             TileMonitor monitor = (TileMonitor) entity;
             // Defer the block update if we're being placed by another TE. See #691
-            if ( livingEntity == null || livingEntity instanceof FakePlayer )
+            if( livingEntity == null || livingEntity instanceof FakePlayer )
             {
                 monitor.updateNeighborsDeferred();
                 return;

src/main/java/dan200/computercraft/shared/peripheral/monitor/TileMonitor.java

@@ -148,7 +148,7 @@ public class TileMonitor extends TileGeneric
     @Override
     public void blockTick()
     {
-        if ( needsUpdate )
+        if( needsUpdate )
         {
             needsUpdate = false;
             updateNeighbors();
@@ -278,8 +278,6 @@ public class TileMonitor extends TileGeneric
 
         int oldXIndex = xIndex;
         int oldYIndex = yIndex;
-        int oldWidth = width;
-        int oldHeight = height;
 
         xIndex = nbt.getInt( NBT_X );
         yIndex = nbt.getInt( NBT_Y );
@@ -299,13 +297,6 @@ public class TileMonitor extends TileGeneric
             // If we're the origin terminal then create it.
             if( clientMonitor == null ) clientMonitor = new ClientMonitor( advanced, this );
         }
-
-        if( oldXIndex != xIndex || oldYIndex != yIndex ||
-            oldWidth != width || oldHeight != height )
-        {
-            // One of our properties has changed, so ensure we redraw the block
-            updateBlock();
-        }
     }
 
     public final void read( TerminalState state )

src/main/java/dan200/computercraft/shared/peripheral/speaker/SpeakerPeripheral.java

@@ -10,17 +10,23 @@ import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
 import dan200.computercraft.api.lua.LuaFunction;
 import dan200.computercraft.api.peripheral.IPeripheral;
+import dan200.computercraft.shared.network.NetworkHandler;
+import dan200.computercraft.shared.network.client.SpeakerMoveClientMessage;
+import dan200.computercraft.shared.network.client.SpeakerPlayClientMessage;
 import net.minecraft.network.play.server.SPlaySoundPacket;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.state.properties.NoteBlockInstrument;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.util.ResourceLocationException;
 import net.minecraft.util.SoundCategory;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.MathHelper;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.world.World;
 
 import javax.annotation.Nonnull;
 import java.util.Optional;
+import java.util.UUID;
 import java.util.concurrent.atomic.AtomicInteger;
 
 import static dan200.computercraft.api.lua.LuaValues.checkFinite;
@@ -32,20 +38,44 @@ import static dan200.computercraft.api.lua.LuaValues.checkFinite;
  */
 public abstract class SpeakerPeripheral implements IPeripheral
 {
+    private static final int MIN_TICKS_BETWEEN_SOUNDS = 1;
+
     private long clock = 0;
     private long lastPlayTime = 0;
     private final AtomicInteger notesThisTick = new AtomicInteger();
 
+    private long lastPositionTime;
+    private Vec3d lastPosition;
+
     public void update()
     {
         clock++;
         notesThisTick.set( 0 );
+
+        // Push position updates to any speakers which have ever played a note,
+        // have moved by a non-trivial amount and haven't had a position update
+        // in the last second.
+        if( lastPlayTime > 0 && (clock - lastPositionTime) >= 20 )
+        {
+            Vec3d position = getPosition();
+            if( lastPosition == null || lastPosition.distanceToSqr( position ) >= 0.1 )
+            {
+                lastPosition = position;
+                lastPositionTime = clock;
+                NetworkHandler.sendToAllTracking(
+                    new SpeakerMoveClientMessage( getSource(), position ),
+                    getWorld().getChunkAt( new BlockPos( position ) )
+                );
+            }
+        }
     }
 
     public abstract World getWorld();
 
     public abstract Vec3d getPosition();
 
+    protected abstract UUID getSource();
+
     public boolean madeSound( long ticks )
     {
         return clock - lastPlayTime <= ticks;
@@ -135,26 +165,37 @@ public abstract class SpeakerPeripheral implements IPeripheral
 
     private synchronized boolean playSound( ILuaContext context, ResourceLocation name, float volume, float pitch, boolean isNote ) throws LuaException
     {
-        if( clock - lastPlayTime < TileSpeaker.MIN_TICKS_BETWEEN_SOUNDS &&
-            (!isNote || clock - lastPlayTime != 0 || notesThisTick.get() >= ComputerCraft.maxNotesPerTick) )
+        if( clock - lastPlayTime < MIN_TICKS_BETWEEN_SOUNDS )
         {
-            // Rate limiting occurs when we've already played a sound within the last tick, or we've
-            // played more notes than allowable within the current tick.
-            return false;
+            // Rate limiting occurs when we've already played a sound within the last tick.
+            if( !isNote ) return false;
+            // Or we've played more notes than allowable within the current tick.
+            if( clock - lastPlayTime != 0 || notesThisTick.get() >= ComputerCraft.maxNotesPerTick ) return false;
         }
 
         World world = getWorld();
         Vec3d pos = getPosition();
 
+        float range = MathHelper.clamp( volume, 1.0f, 3.0f ) * 16;
+
         context.issueMainThreadTask( () -> {
             MinecraftServer server = world.getServer();
             if( server == null ) return null;
 
-            float adjVolume = Math.min( volume, 3.0f );
-            server.getPlayerList().broadcast(
-                null, pos.x, pos.y, pos.z, adjVolume > 1.0f ? 16 * adjVolume : 16.0, world.dimension.getType(),
-                new SPlaySoundPacket( name, SoundCategory.RECORDS, pos, adjVolume, pitch )
-            );
+            if( isNote )
+            {
+                server.getPlayerList().broadcast(
+                    null, pos.x, pos.y, pos.z, range, world.dimension.getType(),
+                    new SPlaySoundPacket( name, SoundCategory.RECORDS, pos, range, pitch )
+                );
+            }
+            else
+            {
+                NetworkHandler.sendToAllAround(
+                    new SpeakerPlayClientMessage( getSource(), pos, name, range, pitch ),
+                    world, pos, range
+                );
+            }
             return null;
         } );
 

src/main/java/dan200/computercraft/shared/peripheral/speaker/TileSpeaker.java

@@ -7,6 +7,8 @@ package dan200.computercraft.shared.peripheral.speaker;
 
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.shared.common.TileGeneric;
+import dan200.computercraft.shared.network.NetworkHandler;
+import dan200.computercraft.shared.network.client.SpeakerStopClientMessage;
 import dan200.computercraft.shared.util.CapabilityUtil;
 import net.minecraft.tileentity.ITickableTileEntity;
 import net.minecraft.tileentity.TileEntityType;
@@ -19,15 +21,15 @@ import net.minecraftforge.common.util.LazyOptional;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
+import java.util.UUID;
 
 import static dan200.computercraft.shared.Capabilities.CAPABILITY_PERIPHERAL;
 
 public class TileSpeaker extends TileGeneric implements ITickableTileEntity
 {
-    public static final int MIN_TICKS_BETWEEN_SOUNDS = 1;
-
     private final SpeakerPeripheral peripheral;
     private LazyOptional<IPeripheral> peripheralCap;
+    private final UUID source = UUID.randomUUID();
 
     public TileSpeaker( TileEntityType<TileSpeaker> type )
     {
@@ -41,6 +43,13 @@ public class TileSpeaker extends TileGeneric implements ITickableTileEntity
         peripheral.update();
     }
 
+    @Override
+    public void setRemoved()
+    {
+        super.setRemoved();
+        NetworkHandler.sendToAllPlayers( new SpeakerStopClientMessage( source ) );
+    }
+
     @Nonnull
     @Override
     public <T> LazyOptional<T> getCapability( @Nonnull Capability<T> cap, @Nullable Direction side )
@@ -83,6 +92,12 @@ public class TileSpeaker extends TileGeneric implements ITickableTileEntity
             return new Vec3d( pos.getX(), pos.getY(), pos.getZ() );
         }
 
+        @Override
+        protected UUID getSource()
+        {
+            return speaker.source;
+        }
+
         @Override
         public boolean equals( @Nullable IPeripheral other )
         {

src/main/java/dan200/computercraft/shared/peripheral/speaker/UpgradeSpeakerPeripheral.java

@@ -0,0 +1,33 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+package dan200.computercraft.shared.peripheral.speaker;
+
+import dan200.computercraft.api.peripheral.IComputerAccess;
+import dan200.computercraft.shared.network.NetworkHandler;
+import dan200.computercraft.shared.network.client.SpeakerStopClientMessage;
+
+import javax.annotation.Nonnull;
+import java.util.UUID;
+
+/**
+ * A speaker peripheral which is used on an upgrade, and so is only attached to one computer.
+ */
+public abstract class UpgradeSpeakerPeripheral extends SpeakerPeripheral
+{
+    private final UUID source = UUID.randomUUID();
+
+    @Override
+    protected final UUID getSource()
+    {
+        return source;
+    }
+
+    @Override
+    public void detach( @Nonnull IComputerAccess computer )
+    {
+        NetworkHandler.sendToAllPlayers( new SpeakerStopClientMessage( source ) );
+    }
+}

src/main/java/dan200/computercraft/shared/pocket/inventory/ContainerPocketComputer.java

@@ -46,7 +46,7 @@ public final class ContainerPocketComputer extends ContainerComputerBase
         public Factory( ServerComputer computer, ItemStack stack, ItemPocketComputer item, Hand hand )
         {
             this.computer = computer;
-            this.name = stack.getHoverName();
+            name = stack.getHoverName();
             this.item = item;
             this.hand = hand;
         }

src/main/java/dan200/computercraft/shared/pocket/peripherals/PocketSpeakerPeripheral.java

@@ -6,11 +6,11 @@
 package dan200.computercraft.shared.pocket.peripherals;
 
 import dan200.computercraft.api.peripheral.IPeripheral;
-import dan200.computercraft.shared.peripheral.speaker.SpeakerPeripheral;
+import dan200.computercraft.shared.peripheral.speaker.UpgradeSpeakerPeripheral;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.world.World;
 
-public class PocketSpeakerPeripheral extends SpeakerPeripheral
+public class PocketSpeakerPeripheral extends UpgradeSpeakerPeripheral
 {
     private World world = null;
     private Vec3d position = Vec3d.ZERO;

src/main/java/dan200/computercraft/shared/proxy/ComputerCraftProxyCommon.java

@@ -1,221 +0,0 @@
-/*
- * This file is part of ComputerCraft - http://www.computercraft.info
- * Copyright Daniel Ratcliffe, 2011-2021. Do not distribute without permission.
- * Send enquiries to dratcliffe@gmail.com
- */
-package dan200.computercraft.shared.proxy;
-
-import dan200.computercraft.ComputerCraft;
-import dan200.computercraft.api.ComputerCraftAPI;
-import dan200.computercraft.api.media.IMedia;
-import dan200.computercraft.api.network.wired.IWiredElement;
-import dan200.computercraft.api.peripheral.IPeripheral;
-import dan200.computercraft.core.computer.MainThread;
-import dan200.computercraft.core.tracking.Tracking;
-import dan200.computercraft.shared.command.CommandComputerCraft;
-import dan200.computercraft.shared.command.arguments.ArgumentSerializers;
-import dan200.computercraft.shared.common.DefaultBundledRedstoneProvider;
-import dan200.computercraft.shared.computer.core.IComputer;
-import dan200.computercraft.shared.computer.core.IContainerComputer;
-import dan200.computercraft.shared.computer.core.ServerComputer;
-import dan200.computercraft.shared.data.BlockNamedEntityLootCondition;
-import dan200.computercraft.shared.data.ConstantLootConditionSerializer;
-import dan200.computercraft.shared.data.HasComputerIdLootCondition;
-import dan200.computercraft.shared.data.PlayerCreativeLootCondition;
-import dan200.computercraft.shared.media.items.RecordMedia;
-import dan200.computercraft.shared.network.NetworkHandler;
-import dan200.computercraft.shared.peripheral.generic.methods.EnergyMethods;
-import dan200.computercraft.shared.peripheral.generic.methods.FluidMethods;
-import dan200.computercraft.shared.peripheral.generic.methods.InventoryMethods;
-import dan200.computercraft.shared.peripheral.modem.wireless.WirelessNetwork;
-import dan200.computercraft.shared.util.NullStorage;
-import net.minecraft.inventory.container.Container;
-import net.minecraft.item.Item;
-import net.minecraft.item.MusicDiscItem;
-import net.minecraft.util.ResourceLocation;
-import net.minecraft.world.storage.loot.ConstantRange;
-import net.minecraft.world.storage.loot.LootPool;
-import net.minecraft.world.storage.loot.LootTables;
-import net.minecraft.world.storage.loot.TableLootEntry;
-import net.minecraft.world.storage.loot.conditions.LootConditionManager;
-import net.minecraftforge.common.capabilities.CapabilityManager;
-import net.minecraftforge.energy.CapabilityEnergy;
-import net.minecraftforge.event.LootTableLoadEvent;
-import net.minecraftforge.event.TickEvent;
-import net.minecraftforge.event.entity.player.PlayerContainerEvent;
-import net.minecraftforge.eventbus.api.SubscribeEvent;
-import net.minecraftforge.fluids.capability.CapabilityFluidHandler;
-import net.minecraftforge.fml.DeferredWorkQueue;
-import net.minecraftforge.fml.common.Mod;
-import net.minecraftforge.fml.event.lifecycle.FMLCommonSetupEvent;
-import net.minecraftforge.fml.event.server.FMLServerStartedEvent;
-import net.minecraftforge.fml.event.server.FMLServerStartingEvent;
-import net.minecraftforge.fml.event.server.FMLServerStoppedEvent;
-import net.minecraftforge.items.CapabilityItemHandler;
-
-import java.util.Arrays;
-import java.util.HashSet;
-import java.util.Set;
-
-@Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, bus = Mod.EventBusSubscriber.Bus.MOD )
-public final class ComputerCraftProxyCommon
-{
-    @SubscribeEvent
-    @SuppressWarnings( "deprecation" )
-    public static void init( FMLCommonSetupEvent event )
-    {
-        NetworkHandler.setup();
-
-        DeferredWorkQueue.runLater( () -> {
-            registerProviders();
-            ArgumentSerializers.register();
-            registerLoot();
-        } );
-
-        ComputerCraftAPI.registerGenericSource( new InventoryMethods() );
-        ComputerCraftAPI.registerGenericSource( new FluidMethods() );
-        ComputerCraftAPI.registerGenericSource( new EnergyMethods() );
-    }
-
-    public static void registerLoot()
-    {
-        LootConditionManager.register( ConstantLootConditionSerializer.of(
-            new ResourceLocation( ComputerCraft.MOD_ID, "block_named" ),
-            BlockNamedEntityLootCondition.class,
-            BlockNamedEntityLootCondition.INSTANCE
-        ) );
-
-        LootConditionManager.register( ConstantLootConditionSerializer.of(
-            new ResourceLocation( ComputerCraft.MOD_ID, "player_creative" ),
-            PlayerCreativeLootCondition.class,
-            PlayerCreativeLootCondition.INSTANCE
-        ) );
-
-        LootConditionManager.register( ConstantLootConditionSerializer.of(
-            new ResourceLocation( ComputerCraft.MOD_ID, "has_id" ),
-            HasComputerIdLootCondition.class,
-            HasComputerIdLootCondition.INSTANCE
-        ) );
-    }
-
-    private static void registerProviders()
-    {
-        // Register bundled power providers
-        ComputerCraftAPI.registerBundledRedstoneProvider( new DefaultBundledRedstoneProvider() );
-
-        // Register media providers
-        ComputerCraftAPI.registerMediaProvider( stack -> {
-            Item item = stack.getItem();
-            if( item instanceof IMedia ) return (IMedia) item;
-            if( item instanceof MusicDiscItem ) return RecordMedia.INSTANCE;
-            return null;
-        } );
-
-        // Register capabilities
-        CapabilityManager.INSTANCE.register( IWiredElement.class, new NullStorage<>(), () -> null );
-        CapabilityManager.INSTANCE.register( IPeripheral.class, new NullStorage<>(), () -> null );
-
-        // Register generic capabilities. This can technically be done off-thread, but we need it to happen
-        // after Forge's common setup, so this is easiest.
-        ComputerCraftAPI.registerGenericCapability( CapabilityItemHandler.ITEM_HANDLER_CAPABILITY );
-        ComputerCraftAPI.registerGenericCapability( CapabilityEnergy.ENERGY );
-        ComputerCraftAPI.registerGenericCapability( CapabilityFluidHandler.FLUID_HANDLER_CAPABILITY );
-    }
-
-    @Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID )
-    public static final class ForgeHandlers
-    {
-        private ForgeHandlers()
-        {
-        }
-
-        /*
-        @SubscribeEvent
-        public static void onConnectionOpened( FMLNetworkEvent.ClientConnectedToServerEvent event )
-        {
-            ComputerCraft.clientComputerRegistry.reset();
-        }
-
-        @SubscribeEvent
-        public static void onConnectionClosed( FMLNetworkEvent.ClientDisconnectionFromServerEvent event )
-        {
-            ComputerCraft.clientComputerRegistry.reset();
-        }
-        */
-
-        @SubscribeEvent
-        public static void onServerTick( TickEvent.ServerTickEvent event )
-        {
-            if( event.phase == TickEvent.Phase.START )
-            {
-                MainThread.executePendingTasks();
-                ComputerCraft.serverComputerRegistry.update();
-            }
-        }
-
-        @SubscribeEvent
-        public static void onContainerOpen( PlayerContainerEvent.Open event )
-        {
-            // If we're opening a computer container then broadcast the terminal state
-            Container container = event.getContainer();
-            if( container instanceof IContainerComputer )
-            {
-                IComputer computer = ((IContainerComputer) container).getComputer();
-                if( computer instanceof ServerComputer )
-                {
-                    ((ServerComputer) computer).sendTerminalState( event.getPlayer() );
-                }
-            }
-        }
-
-        @SubscribeEvent
-        public static void onServerStarting( FMLServerStartingEvent event )
-        {
-            CommandComputerCraft.register( event.getCommandDispatcher() );
-        }
-
-        @SubscribeEvent
-        public static void onServerStarted( FMLServerStartedEvent event )
-        {
-            ComputerCraft.serverComputerRegistry.reset();
-            WirelessNetwork.resetNetworks();
-            Tracking.reset();
-        }
-
-        @SubscribeEvent
-        public static void onServerStopped( FMLServerStoppedEvent event )
-        {
-            ComputerCraft.serverComputerRegistry.reset();
-            WirelessNetwork.resetNetworks();
-            Tracking.reset();
-        }
-
-        public static final ResourceLocation LOOT_TREASURE_DISK = new ResourceLocation( ComputerCraft.MOD_ID, "treasure_disk" );
-
-        private static final Set<ResourceLocation> TABLES = new HashSet<>( Arrays.asList(
-            LootTables.SIMPLE_DUNGEON,
-            LootTables.ABANDONED_MINESHAFT,
-            LootTables.STRONGHOLD_CORRIDOR,
-            LootTables.STRONGHOLD_CROSSING,
-            LootTables.STRONGHOLD_LIBRARY,
-            LootTables.DESERT_PYRAMID,
-            LootTables.JUNGLE_TEMPLE,
-            LootTables.IGLOO_CHEST,
-            LootTables.WOODLAND_MANSION,
-            LootTables.VILLAGE_CARTOGRAPHER
-        ) );
-
-        @SubscribeEvent
-        public static void lootLoad( LootTableLoadEvent event )
-        {
-            ResourceLocation name = event.getName();
-            if( !name.getNamespace().equals( "minecraft" ) || !TABLES.contains( name ) ) return;
-
-            event.getTable().addPool( LootPool.lootPool()
-                .add( TableLootEntry.lootTableReference( LOOT_TREASURE_DISK ) )
-                .setRolls( ConstantRange.exactly( 1 ) )
-                .name( "computercraft_treasure" )
-                .build() );
-        }
-    }
-}

src/main/java/dan200/computercraft/shared/turtle/apis/TurtleAPI.java

@@ -715,7 +715,6 @@ public class TurtleAPI implements ILuaAPI
      *                 more information about the item at the cost of taking longer to run.
      * @return The command result.
      * @throws LuaException If the slot is out of range.
-     * @see InventoryMethods#getItemDetail Describes the information returned by a detailed query.
      * @cc.treturn nil|table Information about the given slot, or {@code nil} if it is empty.
      * @cc.usage Print the current slot, assuming it contains 13 dirt.
      *
@@ -726,6 +725,7 @@ public class TurtleAPI implements ILuaAPI
      * --  count = 13,
      * -- }
      * }</pre>
+     * @see InventoryMethods#getItemDetail Describes the information returned by a detailed query.
      */
     @LuaFunction
     public final MethodResult getItemDetail( ILuaContext context, Optional<Integer> slot, Optional<Boolean> detailed ) throws LuaException

src/main/java/dan200/computercraft/shared/turtle/core/TurtleBrain.java

@@ -160,8 +160,8 @@ public class TurtleBrain implements ITurtleAccess
         overlay = nbt.contains( NBT_OVERLAY ) ? new ResourceLocation( nbt.getString( NBT_OVERLAY ) ) : null;
 
         // Read upgrades
-        setUpgrade( TurtleSide.LEFT, nbt.contains( NBT_LEFT_UPGRADE ) ? TurtleUpgrades.get( nbt.getString( NBT_LEFT_UPGRADE ) ) : null );
-        setUpgrade( TurtleSide.RIGHT, nbt.contains( NBT_RIGHT_UPGRADE ) ? TurtleUpgrades.get( nbt.getString( NBT_RIGHT_UPGRADE ) ) : null );
+        setUpgradeDirect( TurtleSide.LEFT, nbt.contains( NBT_LEFT_UPGRADE ) ? TurtleUpgrades.get( nbt.getString( NBT_LEFT_UPGRADE ) ) : null );
+        setUpgradeDirect( TurtleSide.RIGHT, nbt.contains( NBT_RIGHT_UPGRADE ) ? TurtleUpgrades.get( nbt.getString( NBT_RIGHT_UPGRADE ) ) : null );
 
         // NBT
         upgradeNBTData.clear();
@@ -503,20 +503,15 @@ public class TurtleBrain implements ITurtleAccess
         setFuelLevel( getFuelLevel() + addition );
     }
 
-    private int issueCommand( ITurtleCommand command )
-    {
-        commandQueue.offer( new TurtleCommandQueueEntry( ++commandsIssued, command ) );
-        return commandsIssued;
-    }
-
     @Nonnull
     @Override
     public MethodResult executeCommand( @Nonnull ITurtleCommand command )
     {
         if( getWorld().isClientSide ) throw new UnsupportedOperationException( "Cannot run commands on the client" );
+        if( commandQueue.size() > 16 ) return MethodResult.of( false, "Too many ongoing turtle commands" );
 
-        // Issue command
-        int commandID = issueCommand( command );
+        commandQueue.offer( new TurtleCommandQueueEntry( ++commandsIssued, command ) );
+        int commandID = commandsIssued;
         return new CommandCallback( commandID ).pull;
     }
 
@@ -618,16 +613,30 @@ public class TurtleBrain implements ITurtleAccess
 
     @Override
     public void setUpgrade( @Nonnull TurtleSide side, ITurtleUpgrade upgrade )
+    {
+        if( !setUpgradeDirect( side, upgrade ) ) return;
+
+        // This is a separate function to avoid updating the block when reading the NBT. We don't need to do this as
+        // either the block is newly placed (and so won't have changed) or is being updated with /data, which calls
+        // updateBlock for us.
+        if( owner.getLevel() != null )
+        {
+            owner.updateBlock();
+            owner.updateInput();
+        }
+    }
+
+    private boolean setUpgradeDirect( @Nonnull TurtleSide side, ITurtleUpgrade upgrade )
     {
         // Remove old upgrade
         if( upgrades.containsKey( side ) )
         {
-            if( upgrades.get( side ) == upgrade ) return;
+            if( upgrades.get( side ) == upgrade ) return false;
             upgrades.remove( side );
         }
         else
         {
-            if( upgrade == null ) return;
+            if( upgrade == null ) return false;
         }
 
         upgradeNBTData.remove( side );
@@ -639,8 +648,9 @@ public class TurtleBrain implements ITurtleAccess
         if( owner.getLevel() != null )
         {
             updatePeripherals( owner.createServerComputer() );
-            owner.updateBlock();
         }
+
+        return true;
     }
 
     @Override

src/main/java/dan200/computercraft/shared/turtle/core/TurtleDropCommand.java

@@ -62,7 +62,7 @@ public class TurtleDropCommand implements ITurtleCommand
         IItemHandler inventory = InventoryUtil.getInventory( world, newPosition, side );
 
         // Fire the event, restoring the inventory and exiting if it is cancelled.
-        TurtlePlayer player = TurtlePlaceCommand.createPlayer( turtle, oldPosition, direction );
+        TurtlePlayer player = TurtlePlayer.getWithPosition( turtle, oldPosition, direction );
         TurtleInventoryEvent.Drop event = new TurtleInventoryEvent.Drop( turtle, player, world, newPosition, inventory, stack );
         if( MinecraftForge.EVENT_BUS.post( event ) )
         {

src/main/java/dan200/computercraft/shared/turtle/core/TurtleInspectCommand.java

@@ -50,7 +50,7 @@ public class TurtleInspectCommand implements ITurtleCommand
         Map<String, Object> table = BlockData.fill( new HashMap<>(), state );
 
         // Fire the event, exiting if it is cancelled
-        TurtlePlayer turtlePlayer = TurtlePlaceCommand.createPlayer( turtle, oldPosition, direction );
+        TurtlePlayer turtlePlayer = TurtlePlayer.getWithPosition( turtle, oldPosition, direction );
         TurtleBlockEvent.Inspect event = new TurtleBlockEvent.Inspect( turtle, turtlePlayer, world, newPosition, state, table );
         if( MinecraftForge.EVENT_BUS.post( event ) ) return TurtleCommandResult.failure( event.getFailureMessage() );
 

src/main/java/dan200/computercraft/shared/turtle/core/TurtleMoveCommand.java

@@ -47,7 +47,7 @@ public class TurtleMoveCommand implements ITurtleCommand
         BlockPos oldPosition = turtle.getPosition();
         BlockPos newPosition = oldPosition.relative( direction );
 
-        TurtlePlayer turtlePlayer = TurtlePlaceCommand.createPlayer( turtle, oldPosition, direction );
+        TurtlePlayer turtlePlayer = TurtlePlayer.getWithPosition( turtle, oldPosition, direction );
         TurtleCommandResult canEnterResult = canEnter( turtlePlayer, oldWorld, newPosition );
         if( !canEnterResult.isSuccess() )
         {

src/main/java/dan200/computercraft/shared/turtle/core/TurtlePlaceCommand.java

@@ -12,7 +12,6 @@ import dan200.computercraft.api.turtle.TurtleAnimation;
 import dan200.computercraft.api.turtle.TurtleCommandResult;
 import dan200.computercraft.api.turtle.event.TurtleBlockEvent;
 import dan200.computercraft.shared.TurtlePermissions;
-import dan200.computercraft.shared.util.DirectionUtil;
 import dan200.computercraft.shared.util.DropConsumer;
 import dan200.computercraft.shared.util.InventoryUtil;
 import dan200.computercraft.shared.util.WorldUtil;
@@ -20,6 +19,7 @@ import net.minecraft.block.BlockState;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.LivingEntity;
 import net.minecraft.item.*;
+import net.minecraft.network.play.client.CUseEntityPacket;
 import net.minecraft.tileentity.SignTileEntity;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.ActionResult;
@@ -34,11 +34,13 @@ import net.minecraft.world.World;
 import net.minecraftforge.common.ForgeHooks;
 import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.event.entity.player.PlayerInteractEvent;
-import net.minecraftforge.eventbus.api.Event;
+import net.minecraftforge.items.IItemHandler;
+import net.minecraftforge.items.wrapper.InvWrapper;
 import org.apache.commons.lang3.tuple.Pair;
 
 import javax.annotation.Nonnull;
-import java.util.List;
+
+import static net.minecraftforge.eventbus.api.Event.Result;
 
 public class TurtlePlaceCommand implements ITurtleCommand
 {
@@ -57,10 +59,7 @@ public class TurtlePlaceCommand implements ITurtleCommand
     {
         // Get thing to place
         ItemStack stack = turtle.getInventory().getItem( turtle.getSelectedSlot() );
-        if( stack.isEmpty() )
-        {
-            return TurtleCommandResult.failure( "No items to place" );
-        }
+        if( stack.isEmpty() ) return TurtleCommandResult.failure( "No items to place" );
 
         // Remember old block
         Direction direction = this.direction.toWorldDir( turtle );
@@ -68,144 +67,63 @@ public class TurtlePlaceCommand implements ITurtleCommand
 
         // Create a fake player, and orient it appropriately
         BlockPos playerPosition = turtle.getPosition().relative( direction );
-        TurtlePlayer turtlePlayer = createPlayer( turtle, playerPosition, direction );
+        TurtlePlayer turtlePlayer = TurtlePlayer.getWithPosition( turtle, playerPosition, direction );
 
         TurtleBlockEvent.Place place = new TurtleBlockEvent.Place( turtle, turtlePlayer, turtle.getWorld(), coordinates, stack );
-        if( MinecraftForge.EVENT_BUS.post( place ) )
-        {
-            return TurtleCommandResult.failure( place.getFailureMessage() );
-        }
+        if( MinecraftForge.EVENT_BUS.post( place ) ) return TurtleCommandResult.failure( place.getFailureMessage() );
 
         // Do the deploying
-        String[] errorMessage = new String[1];
-        ItemStack remainder = deploy( stack, turtle, turtlePlayer, direction, extraArguments, errorMessage );
-        if( remainder != stack )
+        turtlePlayer.loadInventory( turtle );
+        ErrorMessage message = new ErrorMessage();
+        boolean result = deploy( stack, turtle, turtlePlayer, direction, extraArguments, message );
+        turtlePlayer.unloadInventory( turtle );
+        if( result )
         {
-            // Put the remaining items back
-            turtle.getInventory().setItem( turtle.getSelectedSlot(), remainder );
-            turtle.getInventory().setChanged();
-
             // Animate and return success
             turtle.playAnimation( TurtleAnimation.WAIT );
             return TurtleCommandResult.success();
         }
+        else if( message.message != null )
+        {
+            return TurtleCommandResult.failure( message.message );
+        }
         else
         {
-            if( errorMessage[0] != null )
-            {
-                return TurtleCommandResult.failure( errorMessage[0] );
-            }
-            else if( stack.getItem() instanceof BlockItem )
-            {
-                return TurtleCommandResult.failure( "Cannot place block here" );
-            }
-            else
-            {
-                return TurtleCommandResult.failure( "Cannot place item here" );
-            }
+            return TurtleCommandResult.failure( stack.getItem() instanceof BlockItem ? "Cannot place block here" : "Cannot place item here" );
         }
     }
 
-    public static ItemStack deploy( @Nonnull ItemStack stack, ITurtleAccess turtle, Direction direction, Object[] extraArguments, String[] outErrorMessage )
+    public static boolean deployCopiedItem( @Nonnull ItemStack stack, ITurtleAccess turtle, Direction direction, Object[] extraArguments, ErrorMessage outErrorMessage )
     {
         // Create a fake player, and orient it appropriately
         BlockPos playerPosition = turtle.getPosition().relative( direction );
-        TurtlePlayer turtlePlayer = createPlayer( turtle, playerPosition, direction );
-
-        return deploy( stack, turtle, turtlePlayer, direction, extraArguments, outErrorMessage );
+        TurtlePlayer turtlePlayer = TurtlePlayer.getWithPosition( turtle, playerPosition, direction );
+        turtlePlayer.loadInventory( stack );
+        boolean result = deploy( stack, turtle, turtlePlayer, direction, extraArguments, outErrorMessage );
+        turtlePlayer.inventory.clearContent();
+        return result;
     }
 
-    public static ItemStack deploy( @Nonnull ItemStack stack, ITurtleAccess turtle, TurtlePlayer turtlePlayer, Direction direction, Object[] extraArguments, String[] outErrorMessage )
+    private static boolean deploy( @Nonnull ItemStack stack, ITurtleAccess turtle, TurtlePlayer turtlePlayer, Direction direction, Object[] extraArguments, ErrorMessage outErrorMessage )
     {
         // Deploy on an entity
-        ItemStack remainder = deployOnEntity( stack, turtle, turtlePlayer, direction, extraArguments, outErrorMessage );
-        if( remainder != stack )
-        {
-            return remainder;
-        }
+        if( deployOnEntity( stack, turtle, turtlePlayer ) ) return true;
 
-        // Deploy on the block immediately in front
         BlockPos position = turtle.getPosition();
         BlockPos newPosition = position.relative( direction );
-        remainder = deployOnBlock( stack, turtle, turtlePlayer, newPosition, direction.getOpposite(), extraArguments, true, outErrorMessage );
-        if( remainder != stack )
-        {
-            return remainder;
-        }
 
-        // Deploy on the block one block away
-        remainder = deployOnBlock( stack, turtle, turtlePlayer, newPosition.relative( direction ), direction.getOpposite(), extraArguments, false, outErrorMessage );
-        if( remainder != stack )
-        {
-            return remainder;
-        }
-
-        if( direction.getAxis() != Direction.Axis.Y )
-        {
+        // Try to deploy against a block. Tries the following options:
+        //     Deploy on the block immediately in front
+        return deployOnBlock( stack, turtle, turtlePlayer, newPosition, direction.getOpposite(), extraArguments, true, outErrorMessage )
+            // Deploy on the block one block away
+            || deployOnBlock( stack, turtle, turtlePlayer, newPosition.relative( direction ), direction.getOpposite(), extraArguments, false, outErrorMessage )
             // Deploy down on the block in front
-            remainder = deployOnBlock( stack, turtle, turtlePlayer, newPosition.below(), Direction.UP, extraArguments, false, outErrorMessage );
-            if( remainder != stack )
-            {
-                return remainder;
-            }
-        }
-
-        // Deploy back onto the turtle
-        remainder = deployOnBlock( stack, turtle, turtlePlayer, position, direction, extraArguments, false, outErrorMessage );
-        if( remainder != stack )
-        {
-            return remainder;
-        }
-
-        // If nothing worked, return the original stack unchanged
-        return stack;
+            || (direction.getAxis() != Direction.Axis.Y && deployOnBlock( stack, turtle, turtlePlayer, newPosition.below(), Direction.UP, extraArguments, false, outErrorMessage ))
+            // Deploy back onto the turtle
+            || deployOnBlock( stack, turtle, turtlePlayer, position, direction, extraArguments, false, outErrorMessage );
     }
 
-    public static TurtlePlayer createPlayer( ITurtleAccess turtle, BlockPos position, Direction direction )
-    {
-        TurtlePlayer turtlePlayer = TurtlePlayer.get( turtle );
-        orientPlayer( turtle, turtlePlayer, position, direction );
-        return turtlePlayer;
-    }
-
-    private static void orientPlayer( ITurtleAccess turtle, TurtlePlayer turtlePlayer, BlockPos position, Direction direction )
-    {
-        double posX = position.getX() + 0.5;
-        double posY = position.getY() + 0.5;
-        double posZ = position.getZ() + 0.5;
-
-        // Stop intersection with the turtle itself
-        if( turtle.getPosition().equals( position ) )
-        {
-            posX += 0.48 * direction.getStepX();
-            posY += 0.48 * direction.getStepY();
-            posZ += 0.48 * direction.getStepZ();
-        }
-
-        if( direction.getAxis() != Direction.Axis.Y )
-        {
-            turtlePlayer.yRot = direction.toYRot();
-            turtlePlayer.xRot = 0.0f;
-        }
-        else
-        {
-            turtlePlayer.yRot = turtle.getDirection().toYRot();
-            turtlePlayer.xRot = DirectionUtil.toPitchAngle( direction );
-        }
-
-        turtlePlayer.setPosRaw( posX, posY, posZ );
-        turtlePlayer.xo = posX;
-        turtlePlayer.yo = posY;
-        turtlePlayer.zo = posZ;
-        turtlePlayer.xRotO = turtlePlayer.xRot;
-        turtlePlayer.yRotO = turtlePlayer.yRot;
-
-        turtlePlayer.yHeadRot = turtlePlayer.yRot;
-        turtlePlayer.yHeadRotO = turtlePlayer.yHeadRot;
-    }
-
-    @Nonnull
-    private static ItemStack deployOnEntity( @Nonnull ItemStack stack, final ITurtleAccess turtle, TurtlePlayer turtlePlayer, Direction direction, Object[] extraArguments, String[] outErrorMessage )
+    private static boolean deployOnEntity( @Nonnull ItemStack stack, final ITurtleAccess turtle, TurtlePlayer turtlePlayer )
     {
         // See if there is an entity present
         final World world = turtle.getWorld();
@@ -213,81 +131,57 @@ public class TurtlePlaceCommand implements ITurtleCommand
         Vec3d turtlePos = turtlePlayer.position();
         Vec3d rayDir = turtlePlayer.getViewVector( 1.0f );
         Pair<Entity, Vec3d> hit = WorldUtil.rayTraceEntities( world, turtlePos, rayDir, 1.5 );
-        if( hit == null )
-        {
-            return stack;
-        }
-
-        // Load up the turtle's inventory
-        ItemStack stackCopy = stack.copy();
-        turtlePlayer.loadInventory( stackCopy );
+        if( hit == null ) return false;
 
         // Start claiming entity drops
         Entity hitEntity = hit.getKey();
         Vec3d hitPos = hit.getValue();
-        DropConsumer.set(
-            hitEntity,
-            drop -> InventoryUtil.storeItems( drop, turtle.getItemHandler(), turtle.getSelectedSlot() )
-        );
 
-        // Place on the entity
-        boolean placed = false;
-        ActionResultType cancelResult = ForgeHooks.onInteractEntityAt( turtlePlayer, hitEntity, hitPos, Hand.MAIN_HAND );
-        if( cancelResult == null )
-        {
-            cancelResult = hitEntity.interactAt( turtlePlayer, hitPos, Hand.MAIN_HAND );
-        }
+        IItemHandler itemHandler = new InvWrapper( turtlePlayer.inventory );
+        DropConsumer.set( hitEntity, drop -> InventoryUtil.storeItems( drop, itemHandler, 1 ) );
 
-        if( cancelResult == ActionResultType.SUCCESS )
-        {
-            placed = true;
-        }
-        else
-        {
-            // See EntityPlayer.interactOn
-            cancelResult = ForgeHooks.onInteractEntity( turtlePlayer, hitEntity, Hand.MAIN_HAND );
-            if( cancelResult == ActionResultType.SUCCESS )
-            {
-                placed = true;
-            }
-            else if( cancelResult == null )
-            {
-                if( hitEntity.interact( turtlePlayer, Hand.MAIN_HAND ) )
-                {
-                    placed = true;
-                }
-                else if( hitEntity instanceof LivingEntity )
-                {
-                    placed = stackCopy.interactEnemy( turtlePlayer, (LivingEntity) hitEntity, Hand.MAIN_HAND );
-                    if( placed ) turtlePlayer.loadInventory( stackCopy );
-                }
-            }
-        }
+        boolean placed = doDeployOnEntity( stack, turtlePlayer, hitEntity, hitPos );
 
-        // Stop claiming drops
-        List<ItemStack> remainingDrops = DropConsumer.clear();
-        for( ItemStack remaining : remainingDrops )
-        {
-            WorldUtil.dropItemStack( remaining, world, position, turtle.getDirection().getOpposite() );
-        }
-
-        // Put everything we collected into the turtles inventory, then return
-        ItemStack remainder = turtlePlayer.unloadInventory( turtle );
-        if( !placed && ItemStack.matches( stack, remainder ) )
-        {
-            return stack;
-        }
-        else if( !remainder.isEmpty() )
-        {
-            return remainder;
-        }
-        else
-        {
-            return ItemStack.EMPTY;
-        }
+        DropConsumer.clearAndDrop( world, position, turtle.getDirection().getOpposite() );
+        return placed;
     }
 
-    private static boolean canDeployOnBlock( @Nonnull BlockItemUseContext context, ITurtleAccess turtle, TurtlePlayer player, BlockPos position, Direction side, boolean allowReplaceable, String[] outErrorMessage )
+    /**
+     * Place a block onto an entity. For instance, feeding cows.
+     *
+     * @param stack        The stack we're placing.
+     * @param turtlePlayer The player of the turtle we're placing.
+     * @param hitEntity    The entity we're interacting with.
+     * @param hitPos       The position our ray trace hit the entity.
+     * @return If this item was deployed.
+     * @see net.minecraft.network.play.ServerPlayNetHandler#handleInteract(CUseEntityPacket)
+     * @see net.minecraft.entity.player.PlayerEntity#interactOn(Entity, Hand)
+     */
+    private static boolean doDeployOnEntity( @Nonnull ItemStack stack, TurtlePlayer turtlePlayer, @Nonnull Entity hitEntity, @Nonnull Vec3d hitPos )
+    {
+        // Placing "onto" a block follows two flows. First we try to interactAt. If that doesn't succeed, then we try to
+        // call the normal interact path. Cancelling an interactAt *does not* cancel a normal interact path.
+
+        ActionResultType interactAt = ForgeHooks.onInteractEntityAt( turtlePlayer, hitEntity, hitPos, Hand.MAIN_HAND );
+        if( interactAt == null ) interactAt = hitEntity.interactAt( turtlePlayer, hitPos, Hand.MAIN_HAND );
+        if( interactAt.consumesAction() ) return true;
+
+        ActionResultType interact = ForgeHooks.onInteractEntity( turtlePlayer, hitEntity, Hand.MAIN_HAND );
+        if( interact != null ) return interact.consumesAction();
+
+        if( hitEntity.interact( turtlePlayer, Hand.MAIN_HAND ) ) return true;
+        if( hitEntity instanceof LivingEntity )
+        {
+            return stack.interactEnemy( turtlePlayer, (LivingEntity) hitEntity, Hand.MAIN_HAND );
+        }
+
+        return false;
+    }
+
+    private static boolean canDeployOnBlock(
+        @Nonnull BlockItemUseContext context, ITurtleAccess turtle, TurtlePlayer player, BlockPos position,
+        Direction side, boolean allowReplaceable, ErrorMessage outErrorMessage
+    )
     {
         World world = turtle.getWorld();
         if( !World.isInWorldBounds( position ) || world.isEmptyBlock( position ) ||
@@ -309,7 +203,7 @@ public class TurtlePlaceCommand implements ITurtleCommand
                 : TurtlePermissions.isBlockEditable( world, position.relative( side ), player );
             if( !editable )
             {
-                if( outErrorMessage != null ) outErrorMessage[0] = "Cannot place in protected area";
+                if( outErrorMessage != null ) outErrorMessage.message = "Cannot place in protected area";
                 return false;
             }
         }
@@ -317,131 +211,123 @@ public class TurtlePlaceCommand implements ITurtleCommand
         return true;
     }
 
-    @Nonnull
-    private static ItemStack deployOnBlock( @Nonnull ItemStack stack, ITurtleAccess turtle, TurtlePlayer turtlePlayer, BlockPos position, Direction side, Object[] extraArguments, boolean allowReplace, String[] outErrorMessage )
+    private static boolean deployOnBlock(
+        @Nonnull ItemStack stack, ITurtleAccess turtle, TurtlePlayer turtlePlayer, BlockPos position, Direction side,
+        Object[] extraArguments, boolean allowReplace, ErrorMessage outErrorMessage
+    )
     {
         // Re-orient the fake player
         Direction playerDir = side.getOpposite();
         BlockPos playerPosition = position.relative( side );
-        orientPlayer( turtle, turtlePlayer, playerPosition, playerDir );
-
-        ItemStack stackCopy = stack.copy();
-        turtlePlayer.loadInventory( stackCopy );
+        turtlePlayer.setPosition( turtle, playerPosition, playerDir );
 
         // Calculate where the turtle would hit the block
         float hitX = 0.5f + side.getStepX() * 0.5f;
         float hitY = 0.5f + side.getStepY() * 0.5f;
         float hitZ = 0.5f + side.getStepZ() * 0.5f;
-        if( Math.abs( hitY - 0.5f ) < 0.01f )
-        {
-            hitY = 0.45f;
-        }
+        if( Math.abs( hitY - 0.5f ) < 0.01f ) hitY = 0.45f;
 
         // Check if there's something suitable to place onto
         BlockRayTraceResult hit = new BlockRayTraceResult( new Vec3d( hitX, hitY, hitZ ), side, position, false );
         ItemUseContext context = new ItemUseContext( turtlePlayer, Hand.MAIN_HAND, hit );
         if( !canDeployOnBlock( new BlockItemUseContext( context ), turtle, turtlePlayer, position, side, allowReplace, outErrorMessage ) )
         {
-            return stack;
+            return false;
         }
 
-        // Load up the turtle's inventory
         Item item = stack.getItem();
-
-        // Do the deploying (put everything in the players inventory)
-        boolean placed = false;
         TileEntity existingTile = turtle.getWorld().getBlockEntity( position );
 
-        // See PlayerInteractionManager.processRightClickBlock
-        // TODO: ^ Check we're still consistent.
-        PlayerInteractEvent.RightClickBlock event = ForgeHooks.onRightClickBlock( turtlePlayer, Hand.MAIN_HAND, position, side );
-        if( !event.isCanceled() )
-        {
-            if( item.onItemUseFirst( stack, context ) == ActionResultType.SUCCESS )
-            {
-                placed = true;
-                turtlePlayer.loadInventory( stackCopy );
-            }
-            else if( event.getUseItem() != Event.Result.DENY &&
-                stackCopy.useOn( context ) == ActionResultType.SUCCESS )
-            {
-                placed = true;
-                turtlePlayer.loadInventory( stackCopy );
-            }
-        }
-
-        if( !placed && (item instanceof BucketItem || item instanceof BoatItem || item instanceof LilyPadItem || item instanceof GlassBottleItem) )
-        {
-            ActionResultType actionResult = ForgeHooks.onItemRightClick( turtlePlayer, Hand.MAIN_HAND );
-            if( actionResult == ActionResultType.SUCCESS )
-            {
-                placed = true;
-            }
-            else if( actionResult == null )
-            {
-                ActionResult<ItemStack> result = stackCopy.use( turtle.getWorld(), turtlePlayer, Hand.MAIN_HAND );
-                if( result.getResult() == ActionResultType.SUCCESS && !ItemStack.matches( stack, result.getObject() ) )
-                {
-                    placed = true;
-                    turtlePlayer.loadInventory( result.getObject() );
-                }
-            }
-        }
+        boolean placed = doDeployOnBlock( stack, turtlePlayer, position, side, context ).consumesAction();
 
         // Set text on signs
-        if( placed && item instanceof SignItem )
+        if( placed && item instanceof SignItem && extraArguments != null && extraArguments.length >= 1 && extraArguments[0] instanceof String )
         {
-            if( extraArguments != null && extraArguments.length >= 1 && extraArguments[0] instanceof String )
+            World world = turtle.getWorld();
+            TileEntity tile = world.getBlockEntity( position );
+            if( tile == null || tile == existingTile )
             {
-                World world = turtle.getWorld();
-                TileEntity tile = world.getBlockEntity( position );
-                if( tile == null || tile == existingTile )
-                {
-                    tile = world.getBlockEntity( position.relative( side ) );
-                }
-                if( tile instanceof SignTileEntity )
-                {
-                    SignTileEntity signTile = (SignTileEntity) tile;
-                    String s = (String) extraArguments[0];
-                    String[] split = s.split( "\n" );
-                    int firstLine = split.length <= 2 ? 1 : 0;
-                    for( int i = 0; i < signTile.messages.length; i++ )
-                    {
-                        if( i >= firstLine && i < firstLine + split.length )
-                        {
-                            if( split[i - firstLine].length() > 15 )
-                            {
-                                signTile.messages[i] = new StringTextComponent( split[i - firstLine].substring( 0, 15 ) );
-                            }
-                            else
-                            {
-                                signTile.messages[i] = new StringTextComponent( split[i - firstLine] );
-                            }
-                        }
-                        else
-                        {
-                            signTile.messages[i] = new StringTextComponent( "" );
-                        }
-                    }
-                    signTile.setChanged();
-                    world.sendBlockUpdated( tile.getBlockPos(), tile.getBlockState(), tile.getBlockState(), 3 );
-                }
+                tile = world.getBlockEntity( position.relative( side ) );
+            }
+
+            if( tile instanceof SignTileEntity ) setSignText( world, tile, (String) extraArguments[0] );
+        }
+
+        return placed;
+    }
+
+    /**
+     * Attempt to place an item into the world. Returns true/false if an item was placed.
+     *
+     * @param stack        The stack the player is using.
+     * @param turtlePlayer The player which represents the turtle
+     * @param position     The block we're deploying against's position.
+     * @param side         The side of the block we're deploying against.
+     * @param context      The context of this place action.
+     * @return If this item was deployed.
+     * @see net.minecraft.server.management.PlayerInteractionManager#useItemOn For the original implementation.
+     */
+    private static ActionResultType doDeployOnBlock(
+        @Nonnull ItemStack stack, TurtlePlayer turtlePlayer, BlockPos position, Direction side, ItemUseContext context
+    )
+    {
+        PlayerInteractEvent.RightClickBlock event = ForgeHooks.onRightClickBlock( turtlePlayer, Hand.MAIN_HAND, position, side );
+        if( event.isCanceled() ) return event.getCancellationResult();
+
+        if( event.getUseItem() != Result.DENY )
+        {
+            ActionResultType result = stack.onItemUseFirst( context );
+            if( result != ActionResultType.PASS ) return result;
+        }
+
+        if( event.getUseItem() != Result.DENY )
+        {
+            ActionResultType result = stack.useOn( context );
+            if( result != ActionResultType.PASS ) return result;
+        }
+
+        Item item = stack.getItem();
+        if( item instanceof BucketItem || item instanceof BoatItem || item instanceof LilyPadItem || item instanceof GlassBottleItem )
+        {
+            ActionResultType actionResult = ForgeHooks.onItemRightClick( turtlePlayer, Hand.MAIN_HAND );
+            if( actionResult != null && actionResult != ActionResultType.PASS ) return actionResult;
+
+            ActionResult<ItemStack> result = stack.use( context.getLevel(), turtlePlayer, Hand.MAIN_HAND );
+            if( result.getResult().consumesAction() && !ItemStack.matches( stack, result.getObject() ) )
+            {
+                turtlePlayer.setItemInHand( Hand.MAIN_HAND, result.getObject() );
+                return result.getResult();
             }
         }
 
-        // Put everything we collected into the turtles inventory, then return
-        ItemStack remainder = turtlePlayer.unloadInventory( turtle );
-        if( !placed && ItemStack.matches( stack, remainder ) )
+        return ActionResultType.PASS;
+    }
+
+    private static void setSignText( World world, TileEntity tile, String message )
+    {
+        SignTileEntity signTile = (SignTileEntity) tile;
+        String[] split = message.split( "\n" );
+        int firstLine = split.length <= 2 ? 1 : 0;
+        for( int i = 0; i < signTile.messages.length; i++ )
         {
-            return stack;
-        }
-        else if( !remainder.isEmpty() )
-        {
-            return remainder;
-        }
-        else
-        {
-            return ItemStack.EMPTY;
+            if( i >= firstLine && i < firstLine + split.length )
+            {
+                String line = split[i - firstLine];
+                signTile.messages[i] = line.length() > 15
+                    ? new StringTextComponent( line.substring( 0, 15 ) )
+                    : new StringTextComponent( line );
+            }
+            else
+            {
+                signTile.messages[i] = new StringTextComponent( "" );
+            }
         }
+        signTile.setChanged();
+        world.sendBlockUpdated( tile.getBlockPos(), tile.getBlockState(), tile.getBlockState(), 3 );
+    }
+
+    private static class ErrorMessage
+    {
+        String message;
     }
 }

src/main/java/dan200/computercraft/shared/turtle/core/TurtlePlayer.java

@@ -9,6 +9,7 @@ import com.mojang.authlib.GameProfile;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.api.turtle.ITurtleAccess;
 import dan200.computercraft.shared.Registry;
+import dan200.computercraft.shared.util.DirectionUtil;
 import dan200.computercraft.shared.util.FakeNetHandler;
 import dan200.computercraft.shared.util.InventoryUtil;
 import dan200.computercraft.shared.util.WorldUtil;
@@ -73,23 +74,6 @@ public final class TurtlePlayer extends FakePlayer
         return profile != null && profile.isComplete() ? profile : DEFAULT_PROFILE;
     }
 
-    private void setState( ITurtleAccess turtle )
-    {
-        if( containerMenu != inventoryMenu )
-        {
-            ComputerCraft.log.warn( "Turtle has open container ({})", containerMenu );
-            doCloseContainer();
-        }
-
-        BlockPos position = turtle.getPosition();
-        setPosRaw( position.getX() + 0.5, position.getY() + 0.5, position.getZ() + 0.5 );
-
-        yRot = turtle.getDirection().toYRot();
-        xRot = 0.0f;
-
-        inventory.clearContent();
-    }
-
     public static TurtlePlayer get( ITurtleAccess access )
     {
         if( !(access instanceof TurtleBrain) ) return create( access );
@@ -109,37 +93,114 @@ public final class TurtlePlayer extends FakePlayer
         return player;
     }
 
-    public void loadInventory( @Nonnull ItemStack currentStack )
+    public static TurtlePlayer getWithPosition( ITurtleAccess turtle, BlockPos position, Direction direction )
     {
-        // Load up the fake inventory
-        inventory.selected = 0;
-        inventory.setItem( 0, currentStack );
+        TurtlePlayer turtlePlayer = get( turtle );
+        turtlePlayer.setPosition( turtle, position, direction );
+        return turtlePlayer;
     }
 
-    public ItemStack unloadInventory( ITurtleAccess turtle )
+    private void setState( ITurtleAccess turtle )
     {
-        // Get the item we placed with
-        ItemStack results = inventory.getItem( 0 );
-        inventory.setItem( 0, ItemStack.EMPTY );
+        if( containerMenu != inventoryMenu )
+        {
+            ComputerCraft.log.warn( "Turtle has open container ({})", containerMenu );
+            doCloseContainer();
+        }
+
+        BlockPos position = turtle.getPosition();
+        setPosRaw( position.getX() + 0.5, position.getY() + 0.5, position.getZ() + 0.5 );
+
+        yRot = turtle.getDirection().toYRot();
+        xRot = 0.0f;
+
+        inventory.clearContent();
+    }
+
+    public void setPosition( ITurtleAccess turtle, BlockPos position, Direction direction )
+    {
+        double posX = position.getX() + 0.5;
+        double posY = position.getY() + 0.5;
+        double posZ = position.getZ() + 0.5;
+
+        // Stop intersection with the turtle itself
+        if( turtle.getPosition().equals( position ) )
+        {
+            posX += 0.48 * direction.getStepX();
+            posY += 0.48 * direction.getStepY();
+            posZ += 0.48 * direction.getStepZ();
+        }
+
+        if( direction.getAxis() != Direction.Axis.Y )
+        {
+            yRot = direction.toYRot();
+            xRot = 0.0f;
+        }
+        else
+        {
+            yRot = turtle.getDirection().toYRot();
+            xRot = DirectionUtil.toPitchAngle( direction );
+        }
+
+        setPosRaw( posX, posY, posZ );
+        xo = posX;
+        yo = posY;
+        zo = posZ;
+        xRotO = xRot;
+        yRotO = yRot;
+
+        yHeadRot = yRot;
+        yHeadRotO = yHeadRot;
+    }
+
+    public void loadInventory( @Nonnull ItemStack stack )
+    {
+        inventory.clearContent();
+        inventory.selected = 0;
+        inventory.setItem( 0, stack );
+    }
+
+    public void loadInventory( @Nonnull ITurtleAccess turtle )
+    {
+        inventory.clearContent();
+
+        int currentSlot = turtle.getSelectedSlot();
+        int slots = turtle.getItemHandler().getSlots();
+
+        // Load up the fake inventory
+        inventory.selected = 0;
+        for( int i = 0; i < slots; i++ )
+        {
+            inventory.setItem( i, turtle.getItemHandler().getStackInSlot( (currentSlot + i) % slots ) );
+        }
+    }
+
+    public void unloadInventory( ITurtleAccess turtle )
+    {
+        int currentSlot = turtle.getSelectedSlot();
+        int slots = turtle.getItemHandler().getSlots();
+
+        // Load up the fake inventory
+        inventory.selected = 0;
+        for( int i = 0; i < slots; i++ )
+        {
+            turtle.getItemHandler().setStackInSlot( (currentSlot + i) % slots, inventory.getItem( i ) );
+        }
 
         // Store (or drop) anything else we found
         BlockPos dropPosition = turtle.getPosition();
         Direction dropDirection = turtle.getDirection().getOpposite();
-        for( int i = 0; i < inventory.getContainerSize(); i++ )
+        int totalSize = inventory.getContainerSize();
+        for( int i = slots; i < totalSize; i++ )
         {
-            ItemStack stack = inventory.getItem( i );
-            if( !stack.isEmpty() )
+            ItemStack remainder = InventoryUtil.storeItems( inventory.getItem( i ), turtle.getItemHandler(), turtle.getSelectedSlot() );
+            if( !remainder.isEmpty() )
             {
-                ItemStack remainder = InventoryUtil.storeItems( stack, turtle.getItemHandler(), turtle.getSelectedSlot() );
-                if( !remainder.isEmpty() )
-                {
-                    WorldUtil.dropItemStack( remainder, turtle.getWorld(), dropPosition, dropDirection );
-                }
-                inventory.setItem( i, ItemStack.EMPTY );
+                WorldUtil.dropItemStack( remainder, turtle.getWorld(), dropPosition, dropDirection );
             }
         }
+
         inventory.setChanged();
-        return results;
     }
 
     @Nonnull

src/main/java/dan200/computercraft/shared/turtle/core/TurtleSuckCommand.java

@@ -58,7 +58,7 @@ public class TurtleSuckCommand implements ITurtleCommand
         IItemHandler inventory = InventoryUtil.getInventory( world, blockPosition, side );
 
         // Fire the event, exiting if it is cancelled.
-        TurtlePlayer player = TurtlePlaceCommand.createPlayer( turtle, turtlePosition, direction );
+        TurtlePlayer player = TurtlePlayer.getWithPosition( turtle, turtlePosition, direction );
         TurtleInventoryEvent.Suck event = new TurtleInventoryEvent.Suck( turtle, player, world, blockPosition, inventory );
         if( MinecraftForge.EVENT_BUS.post( event ) )
         {