Basic network visualiser

The latest version of Cobalt has several major changes, which I'm
looking forward to taking advantage of in the coming months:

 - The Lua interpreter has been split up from the actual LuaClosure
   instance. It now runs multiple functions within one loop, handling
   pushing/popping and resuming method calls correctly.

   This means we have a theoretically infinite call depth, as we're no
   longer bounded by Java's stack size. In reality, this is limited to
   32767 (Short.MAX_VALUE), as that's a mostly equivalent to the limits
   PUC Lua exposes.

 - The stack is no longer unwound in the event of errors. This both
   simplifies error handling (not that CC:T needs to care about that)
   but also means one can call debug.traceback on a now-dead coroutine
   (which is more useful for debugging than using xpcall).

 - Most significantly, coroutines are no longer each run on a dedicated
   thread. Instead, yielding or resuming throws an exception to unwind
   the Java stack and switches to a different coroutine.

   In order to preserve compatability with CC's assumption about LuaJ's
   threading model (namely that yielding blocks the thread), we also
   provide a yieldBlock method (which CC:T consumes). This suspends the
   current thread and switches execution to a new thread (see
   SquidDev/Cobalt@b5ddf164f1 for more
   details). While this does mean we need to use more than 1 thread,
   it's still /substantially/ less than would otherwise be needed.

We've been running these changes on SwitchCraft for a few days now and
haven't seen any issues. One nice thing to observe is that the number of
CC thread has gone down from ~1.9k to ~100 (of those, ~70 are dedicated
to running coroutines). Similarly, the server has gone from generating
~15k threads over its lifetime, to ~3k. While this is still a lot, it's
a substantial improvement.

build.gradle

@@ -10,7 +10,7 @@ buildscript {
     }
     dependencies {
         classpath 'net.minecraftforge.gradle:ForgeGradle:2.3-SNAPSHOT'
-        classpath 'org.ajoberstar:gradle-git:1.6.0'
+        classpath 'org.ajoberstar.grgit:grgit-gradle:3.0.0'
     }
 }
 
@@ -48,7 +48,7 @@ repositories {
     }
     maven {
         name = "squiddev"
-        url = "https://dl.bintray.com/squiddev/maven"
+        url = "https://squiddev.cc/maven"
     }
 
     ivy { artifactPattern "https://asie.pl/files/mods/Charset/LibOnly/[module]-[revision](-[classifier]).[ext]" }
@@ -66,7 +66,7 @@ dependencies {
 
     runtime "mezz.jei:jei_1.12.2:4.8.5.159"
 
-    shade 'org.squiddev:Cobalt:0.4.0'
+    shade 'org.squiddev:Cobalt:0.5.0-SNAPSHOT'
 
     testCompile 'junit:junit:4.11'
 
@@ -99,16 +99,20 @@ processResources {
     inputs.property "version", project.version
     inputs.property "mcversion", project.minecraft.version
 
-    def grgit = Grgit.open(dir: '.')
-    inputs.property "commithash", grgit.head().id
-
-    def blacklist = ['GitHub', 'dan200', 'Daniel Ratcliffe']
+    def hash = 'none'
     Set<String> contributors = []
+    try {
+        def grgit = Grgit.open(dir: '.')
+        hash = grgit.head().id
 
-    grgit.log().each {
-        if (!blacklist.contains(it.author.name)) contributors.add(it.author.name)
-        if (!blacklist.contains(it.committer.name)) contributors.add(it.committer.name)
-    }
+        def blacklist = ['GitHub', 'dan200', 'Daniel Ratcliffe']
+        grgit.log().each {
+            if (!blacklist.contains(it.author.name)) contributors.add(it.author.name)
+            if (!blacklist.contains(it.committer.name)) contributors.add(it.committer.name)
+        }
+    } catch(Exception ignored) { }
+
+    inputs.property "commithash", hash
 
     from(sourceSets.main.resources.srcDirs) {
         include 'mcmod.info'

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

@@ -235,7 +235,8 @@ public class ComputerCraft
     }
 
     @Deprecated
-    public static class Upgrades {
+    public static class Upgrades
+    {
         public static TurtleModem advancedModem;
     }
 

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

@@ -7,6 +7,10 @@
 package dan200.computercraft.client;
 
 import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.client.render.TurtleModelLoader;
+import dan200.computercraft.shared.media.items.ItemDiskLegacy;
+import dan200.computercraft.shared.turtle.items.ItemTurtleBase;
+import dan200.computercraft.shared.util.Colour;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.ItemMeshDefinition;
 import net.minecraft.client.renderer.block.model.IBakedModel;
@@ -17,6 +21,7 @@ import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.ResourceLocation;
+import net.minecraftforge.client.event.ColorHandlerEvent;
 import net.minecraftforge.client.event.ModelBakeEvent;
 import net.minecraftforge.client.event.ModelRegistryEvent;
 import net.minecraftforge.client.event.TextureStitchEvent;
@@ -35,7 +40,7 @@ import javax.annotation.Nonnull;
 @Mod.EventBusSubscriber( modid = ComputerCraft.MOD_ID, value = Side.CLIENT )
 public class ClientRegistry
 {
-    private static final String[] TURTLE_UPGRADES = {
+    private static final String[] EXTRA_MODELS = {
         "turtle_modem_off_left",
         "turtle_modem_on_left",
         "turtle_modem_off_right",
@@ -48,11 +53,16 @@ public class ClientRegistry
         "advanced_turtle_modem_on_right",
         "turtle_speaker_upgrade_left",
         "turtle_speaker_upgrade_right",
+
+        "turtle_white",
+        "turtle_elf_overlay",
     };
 
     @SubscribeEvent
     public static void registerModels( ModelRegistryEvent event )
     {
+        ModelLoaderRegistry.registerLoader( TurtleModelLoader.INSTANCE );
+
         // Register item models
         registerUniversalItemModel( ComputerCraft.Items.computer, "computer" );
         registerItemModel( ComputerCraft.Items.commandComputer, 0, "command_computer" );
@@ -79,35 +89,70 @@ public class ClientRegistry
         registerItemModel( ComputerCraft.Items.printout, 1, "pages" );
         registerItemModel( ComputerCraft.Items.printout, 2, "book" );
 
-        String[] extraTurtleModels = new String[] { "turtle", "turtle_advanced", "turtle_white", "turtle_elf_overlay" };
-        registerUniversalItemModel( ComputerCraft.Items.turtle, "turtle_dynamic", extraTurtleModels );
-        registerUniversalItemModel( ComputerCraft.Items.turtleExpanded, "turtle_dynamic", extraTurtleModels );
-        registerUniversalItemModel( ComputerCraft.Items.turtleAdvanced, "turtle_dynamic", extraTurtleModels );
+        registerUniversalItemModel( ComputerCraft.Items.turtle, "turtle" );
+        registerUniversalItemModel( ComputerCraft.Items.turtleExpanded, "turtle" );
+        registerUniversalItemModel( ComputerCraft.Items.turtleAdvanced, "turtle_advanced" );
     }
 
     @SubscribeEvent
     public static void onTextureStitchEvent( TextureStitchEvent.Pre event )
     {
-        // Load all textures for upgrades
+        // Load all textures for the extra models
         TextureMap map = event.getMap();
-        for( String upgrade : TURTLE_UPGRADES )
+        for( String upgrade : EXTRA_MODELS )
         {
             IModel model = ModelLoaderRegistry.getModelOrMissing( new ResourceLocation( "computercraft", "block/" + upgrade ) );
-            for( ResourceLocation texture : model.getTextures() )
-            {
-                map.registerSprite( texture );
-            }
+            for( ResourceLocation texture : model.getTextures() ) map.registerSprite( texture );
         }
     }
 
     @SubscribeEvent
     public static void onModelBakeEvent( ModelBakeEvent event )
     {
-        // Load all upgrade models
-        for( String upgrade : TURTLE_UPGRADES )
-        {
-            loadBlockModel( event, upgrade );
-        }
+        // Load all extra models
+        for( String model : EXTRA_MODELS ) loadBlockModel( event, model );
+    }
+
+    @SubscribeEvent
+    public static void onItemColours( ColorHandlerEvent.Item event )
+    {
+        event.getItemColors().registerItemColorHandler(
+            ( stack, layer ) -> layer == 0 ? 0xFFFFFF : ((ItemDiskLegacy) stack.getItem()).getColour( stack ),
+            ComputerCraft.Items.disk, ComputerCraft.Items.diskExpanded
+        );
+
+        event.getItemColors().registerItemColorHandler( ( stack, layer ) -> {
+            switch( layer )
+            {
+                case 0:
+                default:
+                    return 0xFFFFFF;
+                case 1:
+                {
+                    // Frame colour
+                    int colour = ComputerCraft.Items.pocketComputer.getColour( stack );
+                    return colour == -1 ? 0xFFFFFF : colour;
+                }
+                case 2:
+                {
+                    // Light colour
+                    int colour = ComputerCraft.Items.pocketComputer.getLightState( stack );
+                    return colour == -1 ? Colour.Black.getHex() : colour;
+                }
+            }
+        }, ComputerCraft.Items.pocketComputer );
+
+        // Setup turtle colours
+        event.getItemColors().registerItemColorHandler( ( stack, tintIndex ) -> {
+            if( tintIndex == 0 )
+            {
+                ItemTurtleBase turtle = (ItemTurtleBase) stack.getItem();
+                int colour = turtle.getColour( stack );
+                if( colour != -1 ) return colour;
+            }
+
+            return 0xFFFFFF;
+        }, ComputerCraft.Blocks.turtle, ComputerCraft.Blocks.turtleExpanded, ComputerCraft.Blocks.turtleAdvanced );
     }
 
     private static void registerItemModel( Item item, int damage, String name )
@@ -118,18 +163,10 @@ public class ClientRegistry
         ModelLoader.setCustomModelResourceLocation( item, damage, res );
     }
 
-    private static void registerUniversalItemModel( Item item, String mainModel, String... extraModels )
+    private static void registerUniversalItemModel( Item item, String mainModel )
     {
         ResourceLocation mainLocation = new ResourceLocation( ComputerCraft.MOD_ID, mainModel );
-
-        ResourceLocation[] modelLocations = new ResourceLocation[extraModels.length + 1];
-        modelLocations[0] = mainLocation;
-        for( int i = 0; i < extraModels.length; i++ )
-        {
-            modelLocations[i + 1] = new ResourceLocation( ComputerCraft.MOD_ID, extraModels[i] );
-        }
-
-        ModelBakery.registerItemVariants( item, modelLocations );
+        ModelBakery.registerItemVariants( item, mainLocation );
 
         final ModelResourceLocation mainModelLocation = new ModelResourceLocation( mainLocation, "inventory" );
         ModelLoader.setCustomMeshDefinition( item, new ItemMeshDefinition()

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

@@ -6,69 +6,19 @@
 
 package dan200.computercraft.client.proxy;
 
-import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.client.render.TileEntityTurtleRenderer;
-import dan200.computercraft.client.render.TurtleSmartItemModel;
 import dan200.computercraft.shared.proxy.CCTurtleProxyCommon;
 import dan200.computercraft.shared.turtle.blocks.TileTurtle;
-import dan200.computercraft.shared.turtle.items.ItemTurtleBase;
-import net.minecraft.client.Minecraft;
-import net.minecraft.client.renderer.block.model.ModelResourceLocation;
-import net.minecraft.client.resources.IReloadableResourceManager;
-import net.minecraft.client.resources.IResourceManager;
-import net.minecraftforge.client.event.ModelBakeEvent;
-import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.fml.client.registry.ClientRegistry;
-import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
 
 public class CCTurtleProxyClient extends CCTurtleProxyCommon
 {
-    @Override
-    public void preInit()
-    {
-        super.preInit();
-        MinecraftForge.EVENT_BUS.register( new ForgeHandlers() );
-    }
-
     @Override
     public void init()
     {
         super.init();
 
-        // Setup turtle colours
-        Minecraft.getMinecraft().getItemColors().registerItemColorHandler( ( stack, tintIndex ) -> {
-            if( tintIndex == 0 )
-            {
-                ItemTurtleBase turtle = (ItemTurtleBase) stack.getItem();
-                int colour = turtle.getColour( stack );
-                if( colour != -1 ) return colour;
-            }
-
-            return 0xFFFFFF;
-        }, ComputerCraft.Blocks.turtle, ComputerCraft.Blocks.turtleExpanded, ComputerCraft.Blocks.turtleAdvanced );
-
         // Setup renderers
         ClientRegistry.bindTileEntitySpecialRenderer( TileTurtle.class, new TileEntityTurtleRenderer() );
     }
-
-    public static class ForgeHandlers
-    {
-        private final TurtleSmartItemModel m_turtleSmartItemModel = new TurtleSmartItemModel();
-
-        ForgeHandlers()
-        {
-            IResourceManager resourceManager = Minecraft.getMinecraft().getResourceManager();
-            if( resourceManager instanceof IReloadableResourceManager )
-            {
-                ((IReloadableResourceManager) resourceManager).registerReloadListener( m_turtleSmartItemModel );
-            }
-        }
-
-        @SubscribeEvent
-        public void onModelBakeEvent( ModelBakeEvent event )
-        {
-            event.getModelRegistry().putObject( new ModelResourceLocation( "computercraft:turtle_dynamic", "inventory" ), m_turtleSmartItemModel );
-        }
-    }
-
 }

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

@@ -10,24 +10,16 @@ import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.client.render.TileEntityCableRenderer;
 import dan200.computercraft.client.render.TileEntityMonitorRenderer;
 import dan200.computercraft.shared.command.CommandCopy;
-import dan200.computercraft.shared.media.items.ItemDiskLegacy;
 import dan200.computercraft.shared.peripheral.modem.wired.TileCable;
 import dan200.computercraft.shared.peripheral.monitor.ClientMonitor;
 import dan200.computercraft.shared.peripheral.monitor.TileMonitor;
 import dan200.computercraft.shared.proxy.ComputerCraftProxyCommon;
-import dan200.computercraft.shared.util.Colour;
-import net.minecraft.client.Minecraft;
-import net.minecraft.client.renderer.color.IItemColor;
-import net.minecraft.item.ItemStack;
 import net.minecraftforge.client.ClientCommandHandler;
 import net.minecraftforge.event.world.WorldEvent;
 import net.minecraftforge.fml.client.registry.ClientRegistry;
 import net.minecraftforge.fml.common.Mod;
 import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
 import net.minecraftforge.fml.relauncher.Side;
-import net.minecraftforge.fml.relauncher.SideOnly;
-
-import javax.annotation.Nonnull;
 
 public class ComputerCraftProxyClient extends ComputerCraftProxyCommon
 {
@@ -45,33 +37,6 @@ public class ComputerCraftProxyClient extends ComputerCraftProxyCommon
     {
         super.init();
 
-        Minecraft mc = Minecraft.getMinecraft();
-
-        // Setup
-        mc.getItemColors().registerItemColorHandler( new DiskColorHandler( ComputerCraft.Items.disk ), ComputerCraft.Items.disk );
-        mc.getItemColors().registerItemColorHandler( new DiskColorHandler( ComputerCraft.Items.diskExpanded ), ComputerCraft.Items.diskExpanded );
-
-        mc.getItemColors().registerItemColorHandler( ( stack, layer ) -> {
-            switch( layer )
-            {
-                case 0:
-                default:
-                    return 0xFFFFFF;
-                case 1:
-                {
-                    // Frame colour
-                    int colour = ComputerCraft.Items.pocketComputer.getColour( stack );
-                    return colour == -1 ? 0xFFFFFF : colour;
-                }
-                case 2:
-                {
-                    // Light colour
-                    int colour = ComputerCraft.Items.pocketComputer.getLightState( stack );
-                    return colour == -1 ? Colour.Black.getHex() : colour;
-                }
-            }
-        }, ComputerCraft.Items.pocketComputer );
-
         // Setup renderers
         ClientRegistry.bindTileEntitySpecialRenderer( TileMonitor.class, new TileEntityMonitorRenderer() );
         ClientRegistry.bindTileEntitySpecialRenderer( TileCable.class, new TileEntityCableRenderer() );
@@ -90,20 +55,5 @@ public class ComputerCraftProxyClient extends ComputerCraftProxyCommon
         }
     }
 
-    @SideOnly( Side.CLIENT )
-    private static class DiskColorHandler implements IItemColor
-    {
-        private final ItemDiskLegacy disk;
 
-        private DiskColorHandler( ItemDiskLegacy disk )
-        {
-            this.disk = disk;
-        }
-
-        @Override
-        public int colorMultiplier( @Nonnull ItemStack stack, int layer )
-        {
-            return layer == 0 ? 0xFFFFFF : disk.getColour( stack );
-        }
-    }
 }

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

@@ -0,0 +1,188 @@
+package dan200.computercraft.client.render;
+
+import com.google.common.collect.Sets;
+import dan200.computercraft.ComputerCraft;
+import dan200.computercraft.api.network.wired.IWiredElement;
+import dan200.computercraft.shared.wired.WiredNetwork;
+import dan200.computercraft.shared.wired.WiredNode;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.gui.FontRenderer;
+import net.minecraft.client.renderer.BufferBuilder;
+import net.minecraft.client.renderer.GlStateManager;
+import net.minecraft.client.renderer.Tessellator;
+import net.minecraft.client.renderer.entity.RenderManager;
+import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
+import net.minecraft.init.Items;
+import net.minecraft.item.ItemStack;
+import net.minecraft.util.math.RayTraceResult;
+import net.minecraft.util.math.Vec3d;
+import net.minecraft.world.World;
+import net.minecraftforge.client.event.RenderWorldLastEvent;
+import net.minecraftforge.fml.common.FMLCommonHandler;
+import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
+import org.lwjgl.opengl.GL11;
+
+import java.awt.*;
+import java.util.Collection;
+import java.util.Set;
+
+/**
+ * This is a helper to render a network when testing.
+ */
+public final class RenderOverlayNetwork
+{
+    private int ticksInGame;
+    private IWiredElement element;
+
+    @SubscribeEvent
+    public void onWorldRenderLast( RenderWorldLastEvent event )
+    {
+        ++ticksInGame;
+
+        RayTraceResult result = Minecraft.getMinecraft().objectMouseOver;
+        if( result != null && result.typeOfHit == RayTraceResult.Type.BLOCK )
+        {
+            World clientWorld = Minecraft.getMinecraft().world;
+            World world = FMLCommonHandler.instance().getMinecraftServerInstance().getWorld( clientWorld.provider.getDimension() );
+
+            IWiredElement newElement = ComputerCraft.getWiredElementAt( world, result.getBlockPos(), result.sideHit );
+            if( newElement != null ) element = newElement;
+        }
+
+        if( element == null ) return;
+
+        Minecraft minecraft = Minecraft.getMinecraft();
+        ItemStack stack = minecraft.player.getHeldItemMainhand();
+        ItemStack otherStack = minecraft.player.getHeldItemOffhand();
+
+        if( stack.getItem() != Items.STICK && otherStack.getItem() != Items.STICK ) return;
+
+        GlStateManager.pushMatrix();
+        RenderManager renderManager = minecraft.getRenderManager();
+        GlStateManager.translate( -renderManager.viewerPosX, -renderManager.viewerPosY, -renderManager.viewerPosZ );
+
+        GlStateManager.disableDepth();
+        GlStateManager.disableTexture2D();
+        GlStateManager.enableBlend();
+        GlStateManager.blendFunc( GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA );
+
+        Set<Pair<IWiredElement>> connections = Sets.newHashSet();
+        WiredNetwork network = (WiredNetwork) element.getNode().getNetwork();
+
+        for( WiredNode node : network.getNodes() )
+        {
+            for( WiredNode other : node.getNeighbours() )
+            {
+                connections.add( new Pair<>( node.getElement(), other.getElement() ) );
+            }
+        }
+
+        renderNetworkConnections( connections, new Color( Color.HSBtoRGB( ticksInGame % 200 / 200F, 0.6F, 1F ) ), 1f );
+
+        GlStateManager.enableDepth();
+        GlStateManager.enableTexture2D();
+        GlStateManager.disableBlend();
+        GlStateManager.popMatrix();
+    }
+
+    private void renderNetworkConnections( Collection<Pair<IWiredElement>> data, Color color, float thickness )
+    {
+        renderConnections( data, color, 1.0f, thickness );
+        renderConnections( data, color, 64.0f / 255.0f, thickness * 3 );
+    }
+
+    private void renderConnections( Collection<Pair<IWiredElement>> connections, Color color, float alpha, float thickness )
+    {
+        Tessellator tessellator = Tessellator.getInstance();
+        BufferBuilder renderer = tessellator.getBuffer();
+
+        GlStateManager.pushMatrix();
+        GlStateManager.scale( 1, 1, 1 );
+
+        GlStateManager.color( color.getRed() / 255.0f, color.getGreen() / 255.0f, color.getBlue() / 255.0f, alpha );
+        GL11.glLineWidth( thickness );
+
+        renderer.begin( GL11.GL_LINES, DefaultVertexFormats.POSITION );
+        for( Pair<IWiredElement> connection : connections )
+        {
+            Vec3d a = connection.x.getPosition(), b = connection.y.getPosition();
+
+            renderer.pos( a.x, a.y, a.z ).endVertex();
+            renderer.pos( b.x, b.y, b.z ).endVertex();
+        }
+
+        tessellator.draw();
+
+        GlStateManager.popMatrix();
+    }
+
+    private void renderLabel( double x, double y, double z, String label )
+    {
+        RenderManager renderManager = Minecraft.getMinecraft().getRenderManager();
+        FontRenderer fontrenderer = renderManager.getFontRenderer();
+        if( fontrenderer == null ) return;
+
+        GlStateManager.pushMatrix();
+        GlStateManager.disableLighting();
+
+        float scale = 0.02666667f;
+        GlStateManager.translate( x, y, z );
+        GlStateManager.rotate( -renderManager.playerViewY, 0, 1, 0 );
+        GlStateManager.rotate( renderManager.playerViewX, 1, 0, 0 );
+        GlStateManager.scale( -scale, -scale, scale );
+
+        // Render label background
+        Tessellator tessellator = Tessellator.getInstance();
+        BufferBuilder renderer = tessellator.getBuffer();
+
+        int width = fontrenderer.getStringWidth( label );
+        int xOffset = width / 2;
+
+        GlStateManager.disableTexture2D();
+        GlStateManager.color( 0, 0, 0, 65 / 225.0f );
+
+        renderer.begin( GL11.GL_QUADS, DefaultVertexFormats.POSITION );
+        renderer.pos( -xOffset - 1, -1, 0 ).endVertex();
+        renderer.pos( -xOffset - 1, 8, 0 ).endVertex();
+        renderer.pos( xOffset + 1, 8, 0 ).endVertex();
+        renderer.pos( xOffset + 1, -1, 0 ).endVertex();
+
+        tessellator.draw();
+        GlStateManager.enableTexture2D();
+
+        // Render label
+        fontrenderer.drawString( label, -width / 2, 0, 0xFFFFFFFF );
+
+        GlStateManager.enableLighting();
+        GlStateManager.popMatrix();
+    }
+
+    private static class Pair<T>
+    {
+        public final T x;
+        public final T y;
+
+        public Pair( T right, T y )
+        {
+            this.x = right;
+            this.y = y;
+        }
+
+        @Override
+        public boolean equals( Object o )
+        {
+            if( this == o ) return true;
+            if( o == null || getClass() != o.getClass() ) return false;
+
+            Pair<?> p = (Pair<?>) o;
+            return (x.equals( p.x ) && y.equals( p.y ))
+                || (x.equals( p.y ) && y.equals( p.x ));
+        }
+
+        @Override
+        public int hashCode()
+        {
+            return x.hashCode() ^ y.hashCode();
+        }
+    }
+}

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

@@ -14,23 +14,20 @@ import dan200.computercraft.shared.util.Holiday;
 import dan200.computercraft.shared.util.HolidayUtil;
 import net.minecraft.block.state.IBlockState;
 import net.minecraft.client.Minecraft;
-import net.minecraft.client.gui.FontRenderer;
 import net.minecraft.client.renderer.BufferBuilder;
+import net.minecraft.client.renderer.EntityRenderer;
 import net.minecraft.client.renderer.GlStateManager;
 import net.minecraft.client.renderer.Tessellator;
 import net.minecraft.client.renderer.block.model.BakedQuad;
 import net.minecraft.client.renderer.block.model.IBakedModel;
 import net.minecraft.client.renderer.block.model.ModelManager;
 import net.minecraft.client.renderer.block.model.ModelResourceLocation;
-import net.minecraft.client.renderer.entity.RenderManager;
 import net.minecraft.client.renderer.texture.TextureMap;
 import net.minecraft.client.renderer.tileentity.TileEntitySpecialRenderer;
 import net.minecraft.client.renderer.vertex.DefaultVertexFormats;
 import net.minecraft.client.renderer.vertex.VertexFormat;
 import net.minecraft.util.EnumFacing;
 import net.minecraft.util.ResourceLocation;
-import net.minecraft.util.math.BlockPos;
-import net.minecraft.util.math.RayTraceResult;
 import net.minecraft.util.math.Vec3d;
 import net.minecraftforge.client.ForgeHooksClient;
 import net.minecraftforge.client.model.pipeline.LightUtil;
@@ -43,7 +40,7 @@ import java.util.List;
 public class TileEntityTurtleRenderer extends TileEntitySpecialRenderer<TileTurtle>
 {
     private static final ModelResourceLocation NORMAL_TURTLE_MODEL = new ModelResourceLocation( "computercraft:turtle", "inventory" );
-    private static final ModelResourceLocation ADVANCED_TURTLE_MODEL = new ModelResourceLocation( "computercraft:turtle_advanced", "inventory" );
+    private static final ModelResourceLocation ADVANCED_TURTLE_MODEL = new ModelResourceLocation( "computercraft:advanced_turtle", "inventory" );
     private static final ModelResourceLocation COLOUR_TURTLE_MODEL = new ModelResourceLocation( "computercraft:turtle_white", "inventory" );
     private static final ModelResourceLocation ELF_OVERLAY_MODEL = new ModelResourceLocation( "computercraft:turtle_elf_overlay", "inventory" );
 
@@ -65,7 +62,7 @@ public class TileEntityTurtleRenderer extends TileEntitySpecialRenderer<TileTurt
         }
     }
 
-    public static ModelResourceLocation getTurtleOverlayModel( ComputerFamily family, ResourceLocation overlay, boolean christmas )
+    public static ModelResourceLocation getTurtleOverlayModel( ResourceLocation overlay, boolean christmas )
     {
         if( overlay != null )
         {
@@ -83,6 +80,19 @@ public class TileEntityTurtleRenderer extends TileEntitySpecialRenderer<TileTurt
 
     private void renderTurtleAt( TileTurtle turtle, double posX, double posY, double posZ, float f, int i )
     {
+        // Render the label
+        String label = turtle.createProxy().getLabel();
+        if( label != null && rendererDispatcher.cameraHitResult != null && turtle.getPos().equals( rendererDispatcher.cameraHitResult.getBlockPos() ) )
+        {
+            setLightmapDisabled( true );
+            EntityRenderer.drawNameplate(
+                getFontRenderer(), label,
+                (float) posX + 0.5F, (float) posY + 1.2F, (float) posZ + 0.5F, 0,
+                rendererDispatcher.entityYaw, rendererDispatcher.entityPitch, false, false
+            );
+            setLightmapDisabled( false );
+        }
+
         IBlockState state = turtle.getWorld().getBlockState( turtle.getPos() );
         GlStateManager.pushMatrix();
         try
@@ -94,13 +104,6 @@ public class TileEntityTurtleRenderer extends TileEntitySpecialRenderer<TileTurt
             yaw = turtle.getRenderYaw( f );
             GlStateManager.translate( posX + offset.x, posY + offset.y, posZ + offset.z );
 
-            // Render the label
-            String label = turtle.createProxy().getLabel();
-            if( label != null )
-            {
-                renderLabel( turtle.getAccess().getPosition(), label );
-            }
-
             // Render the turtle
             GlStateManager.translate( 0.5f, 0.5f, 0.5f );
             GlStateManager.rotate( 180.0f - yaw, 0.0f, 1.0f, 0.0f );
@@ -123,7 +126,6 @@ public class TileEntityTurtleRenderer extends TileEntitySpecialRenderer<TileTurt
 
             // Render the overlay
             ModelResourceLocation overlayModel = getTurtleOverlayModel(
-                family,
                 overlay,
                 HolidayUtil.getCurrentHoliday() == Holiday.Christmas
             );
@@ -232,72 +234,4 @@ public class TileEntityTurtleRenderer extends TileEntitySpecialRenderer<TileTurt
         }
         tessellator.draw();
     }
-
-    private void renderLabel( BlockPos position, String label )
-    {
-        Minecraft mc = Minecraft.getMinecraft();
-        RayTraceResult mop = mc.objectMouseOver;
-        if( mop != null && mop.typeOfHit == RayTraceResult.Type.BLOCK && mop.getBlockPos().equals( position ) )
-        {
-            RenderManager renderManager = mc.getRenderManager();
-            FontRenderer fontrenderer = renderManager.getFontRenderer();
-            float scale = 0.016666668F * 1.6f;
-
-            GlStateManager.pushMatrix();
-            GlStateManager.disableLighting();
-            GlStateManager.enableBlend();
-            GlStateManager.blendFunc( GL11.GL_SRC_ALPHA, GL11.GL_ONE_MINUS_SRC_ALPHA );
-            try
-            {
-                GlStateManager.translate( 0.5f, 1.25f, 0.5f );
-                GlStateManager.rotate( -renderManager.playerViewY, 0.0F, 1.0F, 0.0F );
-                GlStateManager.rotate( renderManager.playerViewX, 1.0F, 0.0F, 0.0F );
-                GlStateManager.scale( -scale, -scale, scale );
-
-                int yOffset = 0;
-                int xOffset = fontrenderer.getStringWidth( label ) / 2;
-
-                // Draw background
-                GlStateManager.depthMask( false );
-                GlStateManager.disableDepth();
-                try
-                {
-                    // Quad
-                    GlStateManager.disableTexture2D();
-                    try
-                    {
-                        Tessellator tessellator = Tessellator.getInstance();
-                        BufferBuilder renderer = tessellator.getBuffer();
-                        renderer.begin( GL11.GL_QUADS, DefaultVertexFormats.POSITION_COLOR );
-                        renderer.pos( -xOffset - 1, -1 + yOffset, 0.0D ).color( 0.0F, 0.0F, 0.0F, 0.25F ).endVertex();
-                        renderer.pos( -xOffset - 1, 8 + yOffset, 0.0D ).color( 0.0F, 0.0F, 0.0F, 0.25F ).endVertex();
-                        renderer.pos( xOffset + 1, 8 + yOffset, 0.0D ).color( 0.0F, 0.0F, 0.0F, 0.25F ).endVertex();
-                        renderer.pos( xOffset + 1, -1 + yOffset, 0.0D ).color( 0.0F, 0.0F, 0.0F, 0.25F ).endVertex();
-                        tessellator.draw();
-                    }
-                    finally
-                    {
-                        GlStateManager.enableTexture2D();
-                    }
-
-                    // Text
-                    fontrenderer.drawString( label, -fontrenderer.getStringWidth( label ) / 2, yOffset, 0x20ffffff );
-                }
-                finally
-                {
-                    GlStateManager.enableDepth();
-                    GlStateManager.depthMask( true );
-                }
-
-                // Draw foreground text
-                fontrenderer.drawString( label, -fontrenderer.getStringWidth( label ) / 2, yOffset, -1 );
-            }
-            finally
-            {
-                GlStateManager.disableBlend();
-                GlStateManager.enableLighting();
-                GlStateManager.popMatrix();
-            }
-        }
-    }
 }

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

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

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

@@ -9,7 +9,6 @@ package dan200.computercraft.client.render;
 import com.google.common.base.Objects;
 import dan200.computercraft.api.turtle.ITurtleUpgrade;
 import dan200.computercraft.api.turtle.TurtleSide;
-import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.turtle.items.ItemTurtleBase;
 import dan200.computercraft.shared.util.Holiday;
 import dan200.computercraft.shared.util.HolidayUtil;
@@ -17,15 +16,11 @@ import net.minecraft.block.state.IBlockState;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.renderer.block.model.*;
 import net.minecraft.client.renderer.texture.TextureAtlasSprite;
-import net.minecraft.client.resources.IResourceManager;
 import net.minecraft.entity.EntityLivingBase;
 import net.minecraft.item.ItemStack;
 import net.minecraft.util.EnumFacing;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.world.World;
-import net.minecraftforge.client.resource.IResourceType;
-import net.minecraftforge.client.resource.ISelectiveResourceReloadListener;
-import net.minecraftforge.client.resource.VanillaResourceType;
 import org.apache.commons.lang3.tuple.Pair;
 
 import javax.annotation.Nonnull;
@@ -34,9 +29,8 @@ import javax.vecmath.Matrix4f;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
-import java.util.function.Predicate;
 
-public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceReloadListener
+public class TurtleSmartItemModel implements IBakedModel
 {
     private static final Matrix4f s_identity, s_flip;
 
@@ -53,17 +47,15 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
 
     private static class TurtleModelCombination
     {
-        public final ComputerFamily m_family;
-        public final boolean m_colour;
-        public final ITurtleUpgrade m_leftUpgrade;
-        public final ITurtleUpgrade m_rightUpgrade;
-        public final ResourceLocation m_overlay;
-        public final boolean m_christmas;
-        public final boolean m_flip;
+        final boolean m_colour;
+        final ITurtleUpgrade m_leftUpgrade;
+        final ITurtleUpgrade m_rightUpgrade;
+        final ResourceLocation m_overlay;
+        final boolean m_christmas;
+        final boolean m_flip;
 
-        public TurtleModelCombination( ComputerFamily family, boolean colour, ITurtleUpgrade leftUpgrade, ITurtleUpgrade rightUpgrade, ResourceLocation overlay, boolean christmas, boolean flip )
+        TurtleModelCombination( boolean colour, ITurtleUpgrade leftUpgrade, ITurtleUpgrade rightUpgrade, ResourceLocation overlay, boolean christmas, boolean flip )
         {
-            m_family = family;
             m_colour = colour;
             m_leftUpgrade = leftUpgrade;
             m_rightUpgrade = rightUpgrade;
@@ -79,8 +71,7 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
             if( !(other instanceof TurtleModelCombination) ) return false;
 
             TurtleModelCombination otherCombo = (TurtleModelCombination) other;
-            return otherCombo.m_family == m_family &&
-                otherCombo.m_colour == m_colour &&
+            return otherCombo.m_colour == m_colour &&
                 otherCombo.m_leftUpgrade == m_leftUpgrade &&
                 otherCombo.m_rightUpgrade == m_rightUpgrade &&
                 Objects.equal( otherCombo.m_overlay, m_overlay ) &&
@@ -92,8 +83,7 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
         public int hashCode()
         {
             final int prime = 31;
-            int result = 1;
-            result = prime * result + m_family.hashCode();
+            int result = 0;
             result = prime * result + (m_colour ? 1 : 0);
             result = prime * result + (m_leftUpgrade != null ? m_leftUpgrade.hashCode() : 0);
             result = prime * result + (m_rightUpgrade != null ? m_rightUpgrade.hashCode() : 0);
@@ -104,14 +94,18 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
         }
     }
 
+    private final IBakedModel familyModel;
+    private final IBakedModel colourModel;
+
     private HashMap<TurtleModelCombination, IBakedModel> m_cachedModels;
     private ItemOverrideList m_overrides;
-    private final TurtleModelCombination m_defaultCombination;
 
-    public TurtleSmartItemModel()
+    public TurtleSmartItemModel( IBakedModel familyModel, IBakedModel colourModel )
     {
+        this.familyModel = familyModel;
+        this.colourModel = colourModel;
+
         m_cachedModels = new HashMap<>();
-        m_defaultCombination = new TurtleModelCombination( ComputerFamily.Normal, false, null, null, null, false, false );
         m_overrides = new ItemOverrideList( new ArrayList<>() )
         {
             @Nonnull
@@ -119,7 +113,6 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
             public IBakedModel handleItemState( @Nonnull IBakedModel originalModel, @Nonnull ItemStack stack, @Nullable World world, @Nullable EntityLivingBase entity )
             {
                 ItemTurtleBase turtle = (ItemTurtleBase) stack.getItem();
-                ComputerFamily family = turtle.getFamily( stack );
                 int colour = turtle.getColour( stack );
                 ITurtleUpgrade leftUpgrade = turtle.getUpgrade( stack, TurtleSide.Left );
                 ITurtleUpgrade rightUpgrade = turtle.getUpgrade( stack, TurtleSide.Right );
@@ -127,17 +120,11 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
                 boolean christmas = HolidayUtil.getCurrentHoliday() == Holiday.Christmas;
                 String label = turtle.getLabel( stack );
                 boolean flip = label != null && (label.equals( "Dinnerbone" ) || label.equals( "Grumm" ));
-                TurtleModelCombination combo = new TurtleModelCombination( family, colour != -1, leftUpgrade, rightUpgrade, overlay, christmas, flip );
-                if( m_cachedModels.containsKey( combo ) )
-                {
-                    return m_cachedModels.get( combo );
-                }
-                else
-                {
-                    IBakedModel model = buildModel( combo );
-                    m_cachedModels.put( combo, model );
-                    return model;
-                }
+                TurtleModelCombination combo = new TurtleModelCombination( colour != -1, leftUpgrade, rightUpgrade, overlay, christmas, flip );
+
+                IBakedModel model = m_cachedModels.get( combo );
+                if( model == null ) m_cachedModels.put( combo, model = buildModel( combo ) );
+                return model;
             }
         };
     }
@@ -149,19 +136,13 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
         return m_overrides;
     }
 
-    @Override
-    public void onResourceManagerReload( @Nonnull IResourceManager resourceManager, @Nonnull Predicate<IResourceType> resourcePredicate )
-    {
-        if( resourcePredicate.test( VanillaResourceType.MODELS ) ) m_cachedModels.clear();
-    }
-
     private IBakedModel buildModel( TurtleModelCombination combo )
     {
         Minecraft mc = Minecraft.getMinecraft();
         ModelManager modelManager = mc.getRenderItem().getItemModelMesher().getModelManager();
-        ModelResourceLocation baseModelLocation = TileEntityTurtleRenderer.getTurtleModel( combo.m_family, combo.m_colour );
-        ModelResourceLocation overlayModelLocation = TileEntityTurtleRenderer.getTurtleOverlayModel( combo.m_family, combo.m_overlay, combo.m_christmas );
-        IBakedModel baseModel = modelManager.getModel( baseModelLocation );
+        ModelResourceLocation overlayModelLocation = TileEntityTurtleRenderer.getTurtleOverlayModel( combo.m_overlay, combo.m_christmas );
+
+        IBakedModel baseModel = combo.m_colour ? colourModel : familyModel;
         IBakedModel overlayModel = (overlayModelLocation != null) ? modelManager.getModel( overlayModelLocation ) : null;
         Matrix4f transform = combo.m_flip ? s_flip : s_identity;
         Pair<IBakedModel, Matrix4f> leftModel = (combo.m_leftUpgrade != null) ? combo.m_leftUpgrade.getModel( null, TurtleSide.Left ) : null;
@@ -184,38 +165,36 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
         }
     }
 
-    // These should not be called:
-
     @Nonnull
     @Override
     public List<BakedQuad> getQuads( IBlockState state, EnumFacing facing, long rand )
     {
-        return getDefaultModel().getQuads( state, facing, rand );
+        return familyModel.getQuads( state, facing, rand );
     }
 
     @Override
     public boolean isAmbientOcclusion()
     {
-        return getDefaultModel().isAmbientOcclusion();
+        return familyModel.isAmbientOcclusion();
     }
 
     @Override
     public boolean isGui3d()
     {
-        return getDefaultModel().isGui3d();
+        return familyModel.isGui3d();
     }
 
     @Override
     public boolean isBuiltInRenderer()
     {
-        return getDefaultModel().isBuiltInRenderer();
+        return familyModel.isBuiltInRenderer();
     }
 
     @Nonnull
     @Override
     public TextureAtlasSprite getParticleTexture()
     {
-        return getDefaultModel().getParticleTexture();
+        return familyModel.getParticleTexture();
     }
 
     @Nonnull
@@ -223,18 +202,7 @@ public class TurtleSmartItemModel implements IBakedModel, ISelectiveResourceRelo
     @Deprecated
     public ItemCameraTransforms getItemCameraTransforms()
     {
-        return getDefaultModel().getItemCameraTransforms();
+        return familyModel.getItemCameraTransforms();
     }
 
-    private IBakedModel getDefaultModel()
-    {
-        IBakedModel model = m_cachedModels.get( m_defaultCombination );
-        if( model == null )
-        {
-            model = buildModel( m_defaultCombination );
-            m_cachedModels.put( m_defaultCombination, model );
-        }
-
-        return model;
-    }
 }

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

@@ -161,7 +161,10 @@ public class Websocket extends Resource<Websocket>
                     }
                 } )
                 .remoteAddress( socketAddress )
-                .connect();
+                .connect()
+                .addListener( c -> {
+                    if( !c.isSuccess() ) failure( c.cause().getMessage() );
+                } );
 
             // Do an additional check for cancellation
             checkClosed();

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

@@ -16,6 +16,7 @@ import java.util.WeakHashMap;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.ThreadFactory;
+import java.util.concurrent.locks.LockSupport;
 
 public class ComputerThread
 {
@@ -216,22 +217,37 @@ public class ComputerThread
                     // Interrupt the thread
                     if( !done )
                     {
-                        StringBuilder builder = new StringBuilder( "Terminating " );
-                        if( computer != null )
+                        if( ComputerCraft.logPeripheralErrors )
                         {
-                            builder.append( "computer " ).append( computer.getID() );
-                        }
-                        else
-                        {
-                            builder.append( "unknown computer" );
-                        }
+                            long time = System.nanoTime() - start;
+                            StringBuilder builder = new StringBuilder( "Terminating " );
+                            if( computer != null )
+                            {
+                                builder.append( "computer #" ).append( computer.getID() );
+                            }
+                            else
+                            {
+                                builder.append( "unknown computer" );
+                            }
 
-                        builder.append( ". Thread is currently running" );
-                        for( StackTraceElement element : thread.getStackTrace() )
-                        {
-                            builder.append( "\n  at " ).append( element );
+                            {
+                                builder.append( " due to timeout (running for " )
+                                    .append( time / 1e9 )
+                                    .append( " seconds). This is NOT a bug, but may mean a computer is misbehaving. " )
+                                    .append( thread.getName() )
+                                    .append( " is currently " )
+                                    .append( thread.getState() );
+                                Object blocking = LockSupport.getBlocker( thread );
+                                if( blocking != null ) builder.append( "\n  on " ).append( blocking );
+
+                                for( StackTraceElement element : thread.getStackTrace() )
+                                {
+                                    builder.append( "\n  at " ).append( element );
+                                }
+                            }
+
+                            ComputerCraft.log.warn( builder.toString() );
                         }
-                        ComputerCraft.log.error( builder.toString() );
 
                         thread.interrupt();
                         thread = null;

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

@@ -46,7 +46,7 @@ public class CobaltLuaMachine implements ILuaMachine
 {
     private static final ThreadPoolExecutor coroutines = new ThreadPoolExecutor(
         0, Integer.MAX_VALUE,
-        60L, TimeUnit.SECONDS,
+        5L, TimeUnit.MINUTES,
         new SynchronousQueue<>(),
         ThreadUtils.factory( "Coroutine" )
     );
@@ -74,12 +74,12 @@ public class CobaltLuaMachine implements ILuaMachine
                 private boolean hasSoftAbort;
 
                 @Override
-                public void onInstruction( DebugState ds, DebugFrame di, int pc, Varargs extras, int top ) throws LuaError
+                public void onInstruction( DebugState ds, DebugFrame di, int pc ) throws LuaError, UnwindThrowable
                 {
                     int count = ++this.count;
                     if( count > 100000 )
                     {
-                        if( m_hardAbortMessage != null ) LuaThread.yield( m_state, NONE );
+                        if( m_hardAbortMessage != null ) throw HardAbortError.INSTANCE;
                         this.count = 0;
                     }
                     else
@@ -87,13 +87,13 @@ public class CobaltLuaMachine implements ILuaMachine
                         handleSoftAbort();
                     }
 
-                    super.onInstruction( ds, di, pc, extras, top );
+                    super.onInstruction( ds, di, pc );
                 }
 
                 @Override
                 public void poll() throws LuaError
                 {
-                    if( m_hardAbortMessage != null ) LuaThread.yield( m_state, NONE );
+                    if( m_hardAbortMessage != null ) throw HardAbortError.INSTANCE;
                     handleSoftAbort();
                 }
 
@@ -117,7 +117,7 @@ public class CobaltLuaMachine implements ILuaMachine
                     throw new LuaError( message );
                 }
             } )
-            .coroutineFactory( command -> {
+            .yieldThreader( command -> {
                 Tracking.addValue( m_computer, TrackingField.COROUTINES_CREATED, 1 );
                 coroutines.execute( () -> {
                     try
@@ -145,10 +145,10 @@ public class CobaltLuaMachine implements ILuaMachine
         if( ComputerCraft.debug_enable ) m_globals.load( state, new DebugLib() );
 
         // Register custom load/loadstring provider which automatically adds prefixes.
-        LibFunction.bind( state, m_globals, PrefixLoader.class, new String[] { "load", "loadstring" } );
+        LibFunction.bind( m_globals, PrefixLoader.class, new String[] { "load", "loadstring" } );
 
         // Remove globals we don't want to expose
-        // m_globals.rawset( "collectgarbage", Constants.NIL );
+        m_globals.rawset( "collectgarbage", Constants.NIL );
         m_globals.rawset( "dofile", Constants.NIL );
         m_globals.rawset( "loadfile", Constants.NIL );
         m_globals.rawset( "print", Constants.NIL );
@@ -222,26 +222,18 @@ public class CobaltLuaMachine implements ILuaMachine
                 resumeArgs = varargsOf( valueOf( eventName ), toValues( arguments ) );
             }
 
-            Varargs results = m_mainRoutine.resume( resumeArgs );
-            if( m_hardAbortMessage != null )
-            {
-                throw new LuaError( m_hardAbortMessage );
-            }
-            else if( !results.first().checkBoolean() )
-            {
-                throw new LuaError( results.arg( 2 ).checkString() );
-            }
-            else
-            {
-                LuaValue filter = results.arg( 2 );
-                m_eventFilter = filter.isString() ? filter.toString() : null;
-            }
+            Varargs results = LuaThread.run( m_mainRoutine, resumeArgs );
+            if( m_hardAbortMessage != null ) throw new LuaError( m_hardAbortMessage );
+
+            LuaValue filter = results.first();
+            m_eventFilter = filter.isString() ? filter.toString() : null;
 
             if( m_mainRoutine.getStatus().equals( "dead" ) ) unload();
         }
-        catch( LuaError e )
+        catch( LuaError | HardAbortError e )
         {
             unload();
+            ComputerCraft.log.warn( "Top level coroutine errored", e );
         }
         finally
         {
@@ -339,16 +331,12 @@ public class CobaltLuaMachine implements ILuaMachine
                                 {
                                     try
                                     {
-                                        Varargs results = LuaThread.yield( state, toValues( yieldArgs ) );
+                                        Varargs results = LuaThread.yieldBlocking( state, toValues( yieldArgs ) );
                                         return toObjects( results, 1 );
                                     }
-                                    catch( OrphanedThread e )
+                                    catch( LuaError e )
                                     {
-                                        throw new InterruptedException();
-                                    }
-                                    catch( Throwable e )
-                                    {
-                                        throw new RuntimeException( e );
+                                        throw new IllegalStateException( e );
                                     }
                                 }
 
@@ -699,7 +687,7 @@ public class CobaltLuaMachine implements ILuaMachine
                 LuaValue s;
                 try
                 {
-                    s = OperationHelper.call( state, func );
+                    s = OperationHelper.noYield( state, () -> OperationHelper.call( state, func ) );
                 }
                 catch( LuaError e )
                 {
@@ -731,4 +719,16 @@ public class CobaltLuaMachine implements ILuaMachine
             return bytes[offset++];
         }
     }
+
+    private static class HardAbortError extends Error
+    {
+        private static final long serialVersionUID = 7954092008586367501L;
+
+        public static final HardAbortError INSTANCE = new HardAbortError();
+
+        private HardAbortError()
+        {
+            super( "Hard Abort", null, true, false );
+        }
+    }
 }

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

@@ -11,11 +11,9 @@ import net.minecraft.block.ITileEntityProvider;
 import net.minecraft.block.material.Material;
 import net.minecraft.block.state.IBlockState;
 import net.minecraft.entity.player.EntityPlayer;
-import net.minecraft.item.ItemStack;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.EnumFacing;
 import net.minecraft.util.EnumHand;
-import net.minecraft.util.NonNullList;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.IBlockAccess;
 import net.minecraft.world.World;
@@ -35,96 +33,32 @@ public abstract class BlockGeneric extends Block implements ITileEntityProvider
 
     protected abstract TileGeneric createTile( int damage );
 
-    @Override
-    public final void dropBlockAsItemWithChance( World world, @Nonnull BlockPos pos, @Nonnull IBlockState state, float chance, int fortune )
-    {
-    }
-
-    @Override
-    public final void getDrops( @Nonnull NonNullList<ItemStack> drops, IBlockAccess world, BlockPos pos, @Nonnull IBlockState state, int fortune )
-    {
-        TileEntity tile = world.getTileEntity( pos );
-        if( tile instanceof TileGeneric )
-        {
-            TileGeneric generic = (TileGeneric) tile;
-            generic.getDroppedItems( drops, false );
-        }
-    }
-
-    @Override
-    public boolean removedByPlayer( @Nonnull IBlockState state, World world, @Nonnull BlockPos pos, @Nonnull EntityPlayer player, boolean willHarvest )
-    {
-        if( !world.isRemote )
-        {
-            // Drop items
-            boolean creative = player.capabilities.isCreativeMode;
-            dropAllItems( world, pos, creative );
-        }
-
-        // Remove block
-        return super.removedByPlayer( state, world, pos, player, willHarvest );
-    }
-
-    public final void dropAllItems( World world, BlockPos pos, boolean creative )
-    {
-        // Get items to drop
-        NonNullList<ItemStack> drops = NonNullList.create();
-        TileEntity tile = world.getTileEntity( pos );
-        if( tile instanceof TileGeneric )
-        {
-            TileGeneric generic = (TileGeneric) tile;
-            generic.getDroppedItems( drops, creative );
-        }
-
-        // Drop items
-        if( drops.size() > 0 )
-        {
-            for( ItemStack item : drops )
-            {
-                dropItem( world, pos, item );
-            }
-        }
-    }
-
-    public final void dropItem( World world, BlockPos pos, @Nonnull ItemStack stack )
-    {
-        Block.spawnAsEntity( world, pos, stack );
-    }
-
     @Override
     public final void breakBlock( @Nonnull World world, @Nonnull BlockPos pos, @Nonnull IBlockState newState )
     {
         TileEntity tile = world.getTileEntity( pos );
         super.breakBlock( world, pos, newState );
         world.removeTileEntity( pos );
-        if( tile instanceof TileGeneric )
-        {
-            TileGeneric generic = (TileGeneric) tile;
-            generic.destroy();
-        }
+        if( tile instanceof TileGeneric ) ((TileGeneric) tile).destroy();
     }
 
     @Override
     public final boolean onBlockActivated( World world, BlockPos pos, IBlockState state, EntityPlayer player, EnumHand hand, EnumFacing side, float hitX, float hitY, float hitZ )
     {
         TileEntity tile = world.getTileEntity( pos );
-        if( tile instanceof TileGeneric )
-        {
-            TileGeneric generic = (TileGeneric) tile;
-            return generic.onActivate( player, hand, side, hitX, hitY, hitZ );
-        }
-        return false;
+        return tile instanceof TileGeneric && ((TileGeneric) tile).onActivate( player, hand, side, hitX, hitY, hitZ );
     }
 
     @Override
     @Deprecated
-    public final void neighborChanged( IBlockState state, World world, BlockPos pos, Block block, BlockPos neighorPos )
+    public final void neighborChanged( IBlockState state, World world, BlockPos pos, Block block, BlockPos neighbour )
     {
         TileEntity tile = world.getTileEntity( pos );
         if( tile instanceof TileGeneric )
         {
             TileGeneric generic = (TileGeneric) tile;
             generic.onNeighbourChange();
+            generic.onNeighbourChange( neighbour );
         }
     }
 
@@ -132,11 +66,7 @@ public abstract class BlockGeneric extends Block implements ITileEntityProvider
     public final void onNeighborChange( IBlockAccess world, BlockPos pos, BlockPos neighbour )
     {
         TileEntity tile = world.getTileEntity( pos );
-        if( tile instanceof TileGeneric )
-        {
-            TileGeneric generic = (TileGeneric) tile;
-            generic.onNeighbourTileEntityChange( neighbour );
-        }
+        if( tile instanceof TileGeneric ) ((TileGeneric) tile).onNeighbourTileEntityChange( neighbour );
     }
 
     @Override
@@ -157,12 +87,7 @@ public abstract class BlockGeneric extends Block implements ITileEntityProvider
     public final boolean canConnectRedstone( IBlockState state, IBlockAccess world, BlockPos pos, EnumFacing side )
     {
         TileEntity tile = world.getTileEntity( pos );
-        if( tile instanceof TileGeneric )
-        {
-            TileGeneric generic = (TileGeneric) tile;
-            return generic.getRedstoneConnectivity( side );
-        }
-        return false;
+        return tile instanceof TileGeneric && ((TileGeneric) tile).getRedstoneConnectivity( side );
     }
 
     @Override
@@ -172,8 +97,7 @@ public abstract class BlockGeneric extends Block implements ITileEntityProvider
         TileEntity tile = world.getTileEntity( pos );
         if( tile instanceof TileGeneric && tile.hasWorld() )
         {
-            TileGeneric generic = (TileGeneric) tile;
-            return generic.getRedstoneOutput( oppositeSide.getOpposite() );
+            return ((TileGeneric) tile).getRedstoneOutput( oppositeSide.getOpposite() );
         }
         return 0;
     }
@@ -190,8 +114,7 @@ public abstract class BlockGeneric extends Block implements ITileEntityProvider
         TileEntity tile = world.getTileEntity( pos );
         if( tile instanceof TileGeneric )
         {
-            TileGeneric generic = (TileGeneric) tile;
-            return generic.getBundledRedstoneConnectivity( side );
+            return ((TileGeneric) tile).getBundledRedstoneConnectivity( side );
         }
         return false;
     }
@@ -201,8 +124,7 @@ public abstract class BlockGeneric extends Block implements ITileEntityProvider
         TileEntity tile = world.getTileEntity( pos );
         if( tile instanceof TileGeneric && tile.hasWorld() )
         {
-            TileGeneric generic = (TileGeneric) tile;
-            return generic.getBundledRedstoneOutput( side );
+            return ((TileGeneric) tile).getBundledRedstoneOutput( side );
         }
         return 0;
     }

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

@@ -9,14 +9,12 @@ package dan200.computercraft.shared.common;
 import net.minecraft.block.Block;
 import net.minecraft.block.state.IBlockState;
 import net.minecraft.entity.player.EntityPlayer;
-import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.network.NetworkManager;
 import net.minecraft.network.play.server.SPacketUpdateTileEntity;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.EnumFacing;
 import net.minecraft.util.EnumHand;
-import net.minecraft.util.NonNullList;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.World;
 
@@ -55,19 +53,20 @@ public abstract class TileGeneric extends TileEntity
         getWorld().setBlockState( getPos(), newState, 3 );
     }
 
-    public void getDroppedItems( @Nonnull NonNullList<ItemStack> drops, boolean creative )
-    {
-    }
-
     public boolean onActivate( EntityPlayer player, EnumHand hand, EnumFacing side, float hitX, float hitY, float hitZ )
     {
         return false;
     }
 
+    @Deprecated
     public void onNeighbourChange()
     {
     }
 
+    public void onNeighbourChange( @Nonnull BlockPos neighbour )
+    {
+    }
+
     public void onNeighbourTileEntityChange( @Nonnull BlockPos neighbour )
     {
     }

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

@@ -8,11 +8,13 @@ package dan200.computercraft.shared.computer.blocks;
 
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.shared.computer.core.ComputerFamily;
+import dan200.computercraft.shared.computer.items.ComputerItemFactory;
 import net.minecraft.block.material.Material;
 import net.minecraft.block.properties.PropertyDirection;
 import net.minecraft.block.properties.PropertyEnum;
 import net.minecraft.block.state.BlockStateContainer;
 import net.minecraft.block.state.IBlockState;
+import net.minecraft.item.ItemStack;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.EnumFacing;
 import net.minecraft.util.math.BlockPos;
@@ -103,4 +105,11 @@ public class BlockCommandComputer extends BlockComputerBase
     {
         return new TileCommandComputer();
     }
+
+    @Nonnull
+    @Override
+    protected ItemStack getItem( TileComputerBase tile )
+    {
+        return tile instanceof TileCommandComputer ? ComputerItemFactory.create( (TileComputer) tile ) : ItemStack.EMPTY;
+    }
 }

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

@@ -15,14 +15,11 @@ import net.minecraft.block.properties.PropertyDirection;
 import net.minecraft.block.properties.PropertyEnum;
 import net.minecraft.block.state.BlockStateContainer;
 import net.minecraft.block.state.IBlockState;
-import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.item.ItemStack;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.EnumFacing;
 import net.minecraft.util.math.BlockPos;
-import net.minecraft.util.math.RayTraceResult;
 import net.minecraft.world.IBlockAccess;
-import net.minecraft.world.World;
 
 import javax.annotation.Nonnull;
 
@@ -136,9 +133,8 @@ public class BlockComputer extends BlockComputerBase
 
     @Nonnull
     @Override
-    public ItemStack getPickBlock( @Nonnull IBlockState state, RayTraceResult target, @Nonnull World world, @Nonnull BlockPos pos, EntityPlayer player )
+    protected ItemStack getItem( TileComputerBase tile )
     {
-        TileEntity tile = world.getTileEntity( pos );
-        return tile instanceof TileComputer ? ComputerItemFactory.create( (TileComputer) tile ) : super.getPickBlock( state, target, world, pos, player );
+        return tile instanceof TileComputer ? ComputerItemFactory.create( (TileComputer) tile ) : ItemStack.EMPTY;
     }
 }

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

@@ -12,9 +12,13 @@ import dan200.computercraft.shared.util.DirectionUtil;
 import net.minecraft.block.material.Material;
 import net.minecraft.block.state.IBlockState;
 import net.minecraft.entity.EntityLivingBase;
+import net.minecraft.entity.player.EntityPlayer;
+import net.minecraft.item.ItemStack;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.EnumFacing;
+import net.minecraft.util.NonNullList;
 import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.RayTraceResult;
 import net.minecraft.world.IBlockAccess;
 import net.minecraft.world.World;
 
@@ -49,6 +53,9 @@ public abstract class BlockComputerBase extends BlockDirectional
 
     protected abstract TileComputerBase createTile( ComputerFamily family );
 
+    @Nonnull
+    protected abstract ItemStack getItem( TileComputerBase tile );
+
     @Nonnull
     @Override
     @Deprecated
@@ -83,4 +90,55 @@ public abstract class BlockComputerBase extends BlockDirectional
             computer.updateInput();
         }
     }
+
+    @Override
+    @Nonnull
+    public ItemStack getPickBlock( @Nonnull IBlockState state, RayTraceResult target, @Nonnull World world, @Nonnull BlockPos pos, EntityPlayer player )
+    {
+        TileEntity tile = world.getTileEntity( pos );
+        if( tile instanceof TileComputerBase )
+        {
+            ItemStack result = getItem( (TileComputerBase) tile );
+            if( !result.isEmpty() ) return result;
+        }
+
+        return super.getPickBlock( state, target, world, pos, player );
+    }
+
+    @Override
+    public final void dropBlockAsItemWithChance( World world, @Nonnull BlockPos pos, @Nonnull IBlockState state, float chance, int fortune )
+    {
+    }
+
+    @Override
+    public final void getDrops( @Nonnull NonNullList<ItemStack> drops, IBlockAccess world, BlockPos pos, @Nonnull IBlockState state, int fortune )
+    {
+        TileEntity tile = world.getTileEntity( pos );
+        if( tile instanceof TileComputerBase )
+        {
+            ItemStack stack = getItem( (TileComputerBase) tile );
+            if( !stack.isEmpty() ) drops.add( stack );
+        }
+    }
+
+    @Override
+    public boolean removedByPlayer( @Nonnull IBlockState state, World world, @Nonnull BlockPos pos, @Nonnull EntityPlayer player, boolean willHarvest )
+    {
+        if( !world.isRemote )
+        {
+            // We drop the item here instead of doing it in the harvest method, as we
+            // need to drop it for creative players too.
+            TileEntity tile = world.getTileEntity( pos );
+            if( tile instanceof TileComputerBase )
+            {
+                TileComputerBase computer = (TileComputerBase) tile;
+                if( !player.capabilities.isCreativeMode || computer.getLabel() != null )
+                {
+                    spawnAsEntity( world, pos, getItem( computer ) );
+                }
+            }
+        }
+
+        return super.removedByPlayer( state, world, pos, player, willHarvest );
+    }
 }

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

@@ -9,13 +9,10 @@ package dan200.computercraft.shared.computer.blocks;
 import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.computer.core.ServerComputer;
-import dan200.computercraft.shared.computer.items.ComputerItemFactory;
 import net.minecraft.block.state.IBlockState;
 import net.minecraft.entity.player.EntityPlayer;
-import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.util.EnumFacing;
-import net.minecraft.util.NonNullList;
 
 import javax.annotation.Nonnull;
 
@@ -60,12 +57,6 @@ public class TileComputer extends TileComputerBase
         return m_proxy;
     }
 
-    @Override
-    public void getDroppedItems( @Nonnull NonNullList<ItemStack> drops, boolean creative )
-    {
-        if( !creative || getLabel() != null ) drops.add( ComputerItemFactory.create( this ) );
-    }
-
     @Override
     public void openGUI( EntityPlayer player )
     {

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

@@ -173,9 +173,9 @@ public abstract class TileComputerBase extends TileGeneric implements IComputerT
     }
 
     @Override
-    public void onNeighbourChange()
+    public void onNeighbourChange( @Nonnull BlockPos neighbour )
     {
-        updateInput();
+        updateInput( neighbour );
     }
 
     @Override
@@ -296,7 +296,7 @@ public abstract class TileComputerBase extends TileGeneric implements IComputerT
         int localDir = remapLocalSide( DirectionUtil.toLocal( this, dir ) );
         if( !isRedstoneBlockedOnSide( localDir ) )
         {
-            computer.setRedstoneInput( localDir, getWorld().getRedstonePower( offset, offsetSide ) );
+            computer.setRedstoneInput( localDir, getWorld().getRedstonePower( offset, dir ) );
             computer.setBundledRedstoneInput( localDir, BundledRedstone.getOutput( getWorld(), offset, offsetSide ) );
         }
         if( !isPeripheralBlockedOnSide( localDir ) )

src/main/java/dan200/computercraft/shared/peripheral/common/BlockPeripheral.java

@@ -29,6 +29,7 @@ import net.minecraft.item.ItemStack;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.BlockRenderLayer;
 import net.minecraft.util.EnumFacing;
+import net.minecraft.util.NonNullList;
 import net.minecraft.util.math.AxisAlignedBB;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.RayTraceResult;
@@ -375,17 +376,9 @@ public class BlockPeripheral extends BlockGeneric
         {
             case DiskDrive:
             default:
-            {
-                IBlockState state = getDefaultState().withProperty( Properties.VARIANT, BlockPeripheralVariant.DiskDriveEmpty );
-                if( placedSide.getAxis() != EnumFacing.Axis.Y )
-                {
-                    return state.withProperty( Properties.FACING, placedSide );
-                }
-                else
-                {
-                    return state.withProperty( Properties.FACING, EnumFacing.NORTH );
-                }
-            }
+                return getDefaultState()
+                    .withProperty( Properties.VARIANT, BlockPeripheralVariant.DiskDriveEmpty )
+                    .withProperty( Properties.FACING, placedSide.getAxis() == EnumFacing.Axis.Y ? EnumFacing.NORTH : placedSide );
             case WirelessModem:
             {
                 EnumFacing dir = placedSide.getOpposite();
@@ -409,21 +402,13 @@ public class BlockPeripheral extends BlockGeneric
                 }
             }
             case Monitor:
-            {
                 return getDefaultState().withProperty( Properties.VARIANT, BlockPeripheralVariant.Monitor );
-            }
             case Printer:
-            {
                 return getDefaultState().withProperty( Properties.VARIANT, BlockPeripheralVariant.PrinterEmpty );
-            }
             case AdvancedMonitor:
-            {
                 return getDefaultState().withProperty( Properties.VARIANT, BlockPeripheralVariant.AdvancedMonitor );
-            }
             case Speaker:
-            {
                 return getDefaultState().withProperty( Properties.VARIANT, BlockPeripheralVariant.Speaker );
-            }
         }
     }
 
@@ -465,19 +450,15 @@ public class BlockPeripheral extends BlockGeneric
             case Speaker:
             case DiskDrive:
             case Printer:
-            {
-                EnumFacing dir = DirectionUtil.fromEntityRot( player );
-                if( stack.hasDisplayName() && tile instanceof TilePeripheralBase )
+                if( tile instanceof TilePeripheralBase )
                 {
                     TilePeripheralBase peripheral = (TilePeripheralBase) tile;
-                    peripheral.setLabel( stack.getDisplayName() );
-                    peripheral.setDirection( dir );
+                    peripheral.setDirection( DirectionUtil.fromEntityRot( player ) );
+                    if( stack.hasDisplayName() ) peripheral.setLabel( stack.getDisplayName() );
                 }
                 break;
-            }
             case Monitor:
             case AdvancedMonitor:
-            {
                 if( tile instanceof TileMonitor )
                 {
                     int direction = DirectionUtil.fromEntityRot( player ).getIndex();
@@ -504,7 +485,6 @@ public class BlockPeripheral extends BlockGeneric
                     }
                 }
                 break;
-            }
         }
     }
 
@@ -600,4 +580,10 @@ public class BlockPeripheral extends BlockGeneric
             ? PeripheralItemFactory.create( (ITilePeripheral) tile )
             : super.getPickBlock( state, target, world, pos, player );
     }
+
+    @Override
+    public void getDrops( @Nonnull NonNullList<ItemStack> drops, IBlockAccess world, BlockPos pos, @Nonnull IBlockState state, int fortune )
+    {
+        drops.add( PeripheralItemFactory.create( getPeripheralType( state ), null, 1 ) );
+    }
 }

src/main/java/dan200/computercraft/shared/peripheral/common/TilePeripheralBase.java

@@ -10,11 +10,9 @@ import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.shared.common.IDirectionalTile;
 import dan200.computercraft.shared.common.TileGeneric;
 import dan200.computercraft.shared.peripheral.PeripheralType;
-import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.util.EnumFacing;
 import net.minecraft.util.ITickable;
-import net.minecraft.util.NonNullList;
 
 import javax.annotation.Nonnull;
 
@@ -42,15 +40,6 @@ public abstract class TilePeripheralBase extends TileGeneric implements IPeriphe
         return (BlockPeripheral) super.getBlock();
     }
 
-    @Override
-    public void getDroppedItems( @Nonnull NonNullList<ItemStack> drops, boolean creative )
-    {
-        if( !creative )
-        {
-            drops.add( PeripheralItemFactory.create( this ) );
-        }
-    }
-
     @Override
     public final PeripheralType getPeripheralType()
     {

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

@@ -14,6 +14,7 @@ import dan200.computercraft.shared.common.TileGeneric;
 import dan200.computercraft.shared.peripheral.PeripheralType;
 import dan200.computercraft.shared.peripheral.common.PeripheralItemFactory;
 import dan200.computercraft.shared.util.WorldUtil;
+import net.minecraft.block.Block;
 import net.minecraft.block.material.Material;
 import net.minecraft.block.properties.PropertyBool;
 import net.minecraft.block.properties.PropertyEnum;
@@ -26,6 +27,7 @@ import net.minecraft.entity.player.EntityPlayer;
 import net.minecraft.item.ItemStack;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.EnumFacing;
+import net.minecraft.util.NonNullList;
 import net.minecraft.util.math.AxisAlignedBB;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.RayTraceResult;
@@ -322,7 +324,10 @@ public class BlockCable extends BlockGeneric
 
                     cable.modemChanged();
                     cable.connectionsChanged();
-                    if( !world.isRemote && !player.capabilities.isCreativeMode ) dropItem( world, pos, item );
+                    if( !world.isRemote && !player.capabilities.isCreativeMode )
+                    {
+                        Block.spawnAsEntity( world, pos, item );
+                    }
 
                     return false;
                 }
@@ -332,6 +337,23 @@ public class BlockCable extends BlockGeneric
         return super.removedByPlayer( state, world, pos, player, willHarvest );
     }
 
+    @Override
+    public void getDrops( @Nonnull NonNullList<ItemStack> drops, IBlockAccess world, BlockPos pos, @Nonnull IBlockState state, int fortune )
+    {
+        PeripheralType type = getPeripheralType( state );
+        switch( type )
+        {
+            case Cable:
+            case WiredModem:
+                drops.add( PeripheralItemFactory.create( type, null, 1 ) );
+                break;
+            case WiredModemWithCable:
+                drops.add( PeripheralItemFactory.create( PeripheralType.WiredModem, null, 1 ) );
+                drops.add( PeripheralItemFactory.create( PeripheralType.Cable, null, 1 ) );
+                break;
+        }
+    }
+
     @Nonnull
     @Override
     public ItemStack getPickBlock( @Nonnull IBlockState state, RayTraceResult hit, @Nonnull World world, @Nonnull BlockPos pos, EntityPlayer player )

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

@@ -20,13 +20,12 @@ import dan200.computercraft.shared.peripheral.common.PeripheralItemFactory;
 import dan200.computercraft.shared.peripheral.modem.ModemState;
 import dan200.computercraft.shared.util.TickScheduler;
 import dan200.computercraft.shared.wired.CapabilityWiredElement;
+import net.minecraft.block.Block;
 import net.minecraft.block.state.IBlockState;
 import net.minecraft.entity.player.EntityPlayer;
-import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.util.EnumFacing;
 import net.minecraft.util.EnumHand;
-import net.minecraft.util.NonNullList;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.util.text.TextComponentTranslation;
@@ -177,44 +176,17 @@ public class TileCable extends TileGeneric implements IPeripheralTile
     }
 
     @Override
-    public void getDroppedItems( @Nonnull NonNullList<ItemStack> drops, boolean creative )
-    {
-        if( !creative )
-        {
-            PeripheralType type = getPeripheralType();
-            switch( type )
-            {
-                case Cable:
-                case WiredModem:
-                {
-                    drops.add( PeripheralItemFactory.create( type, null, 1 ) );
-                    break;
-                }
-                case WiredModemWithCable:
-                {
-                    drops.add( PeripheralItemFactory.create( PeripheralType.WiredModem, null, 1 ) );
-                    drops.add( PeripheralItemFactory.create( PeripheralType.Cable, null, 1 ) );
-                    break;
-                }
-            }
-        }
-    }
-
-    @Override
-    public void onNeighbourChange()
+    public void onNeighbourChange( @Nonnull BlockPos neighbour )
     {
         EnumFacing dir = getDirection();
-        if( !getWorld().isSideSolid(
-            getPos().offset( dir ),
-            dir.getOpposite()
-        ) )
+        if( neighbour.equals( getPos().offset( dir ) ) && !getWorld().isSideSolid( neighbour, dir.getOpposite() ) )
         {
             switch( getPeripheralType() )
             {
                 case WiredModem:
                 {
                     // Drop everything and remove block
-                    getBlock().dropAllItems( getWorld(), getPos(), false );
+                    getBlock().dropBlockAsItem( getWorld(), getPos(), getBlockState(), 0 );
                     getWorld().setBlockToAir( getPos() );
 
                     // This'll call #destroy(), so we don't need to reset the network here.
@@ -223,7 +195,7 @@ public class TileCable extends TileGeneric implements IPeripheralTile
                 case WiredModemWithCable:
                 {
                     // Drop the modem and convert to cable
-                    getBlock().dropItem( getWorld(), getPos(), PeripheralItemFactory.create( PeripheralType.WiredModem, null, 1 ) );
+                    Block.spawnAsEntity( getWorld(), getPos(), PeripheralItemFactory.create( PeripheralType.WiredModem, null, 1 ) );
                     setBlockState( getBlockState().withProperty( BlockCable.Properties.MODEM, BlockCableModemVariant.None ) );
                     modemChanged();
                     connectionsChanged();

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

@@ -7,7 +7,6 @@
 package dan200.computercraft.shared.peripheral.modem.wired;
 
 import com.google.common.base.Objects;
-import dan200.computercraft.ComputerCraft;
 import dan200.computercraft.api.ComputerCraftAPI;
 import dan200.computercraft.api.network.wired.IWiredElement;
 import dan200.computercraft.api.network.wired.IWiredNode;
@@ -19,11 +18,9 @@ import dan200.computercraft.shared.peripheral.modem.ModemState;
 import dan200.computercraft.shared.util.TickScheduler;
 import dan200.computercraft.shared.wired.CapabilityWiredElement;
 import net.minecraft.entity.player.EntityPlayer;
-import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.util.EnumFacing;
 import net.minecraft.util.EnumHand;
-import net.minecraft.util.NonNullList;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.util.text.TextComponentString;
@@ -136,24 +133,9 @@ public class TileWiredModemFull extends TileGeneric implements IPeripheralTile
     }
 
     @Override
-    public void getDroppedItems( @Nonnull NonNullList<ItemStack> drops, boolean creative )
+    public void onNeighbourChange( @Nonnull BlockPos neighbour )
     {
-        drops.add( new ItemStack( ComputerCraft.Items.wiredModemFull ) );
-    }
-
-    @Override
-    public void onNeighbourChange()
-    {
-        if( !world.isRemote && m_peripheralAccessAllowed )
-        {
-            boolean hasChanged = false;
-            for( EnumFacing facing : EnumFacing.VALUES )
-            {
-                hasChanged |= m_peripherals[facing.ordinal()].attach( world, getPos(), facing );
-            }
-
-            if( hasChanged ) updateConnectedPeripherals();
-        }
+        onNeighbourTileEntityChange( neighbour );
     }
 
     @Override

src/main/java/dan200/computercraft/shared/peripheral/modem/wireless/TileAdvancedModem.java

@@ -6,24 +6,18 @@
 
 package dan200.computercraft.shared.peripheral.modem.wireless;
 
-import dan200.computercraft.ComputerCraft;
-import net.minecraft.item.ItemStack;
 import net.minecraft.util.EnumFacing;
-import net.minecraft.util.NonNullList;
-
-import javax.annotation.Nonnull;
 
 public class TileAdvancedModem extends TileWirelessModemBase
 {
+    public TileAdvancedModem()
+    {
+        super( true );
+    }
+
     @Override
     protected EnumFacing getDirection()
     {
         return getBlockState().getValue( BlockAdvancedModem.Properties.FACING );
     }
-
-    @Override
-    public void getDroppedItems( @Nonnull NonNullList<ItemStack> drops, boolean creative )
-    {
-        if( !creative ) drops.add( new ItemStack( ComputerCraft.Items.advancedModem ) );
-    }
 }

src/main/java/dan200/computercraft/shared/peripheral/modem/wireless/TileWirelessModem.java

@@ -12,11 +12,8 @@ import dan200.computercraft.shared.peripheral.PeripheralType;
 import dan200.computercraft.shared.peripheral.common.BlockPeripheral;
 import dan200.computercraft.shared.peripheral.common.BlockPeripheralVariant;
 import dan200.computercraft.shared.peripheral.common.ITilePeripheral;
-import dan200.computercraft.shared.peripheral.common.PeripheralItemFactory;
 import net.minecraft.block.state.IBlockState;
-import net.minecraft.item.ItemStack;
 import net.minecraft.util.EnumFacing;
-import net.minecraft.util.NonNullList;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.World;
 
@@ -24,6 +21,11 @@ import javax.annotation.Nonnull;
 
 public class TileWirelessModem extends TileWirelessModemBase implements IDirectionalTile, ITilePeripheral
 {
+    public TileWirelessModem()
+    {
+        super( false );
+    }
+
     @Override
     public EnumFacing getDirection()
     {
@@ -75,12 +77,6 @@ public class TileWirelessModem extends TileWirelessModemBase implements IDirecti
         return super.shouldRefresh( world, pos, oldState, newState ) || ComputerCraft.Blocks.peripheral.getPeripheralType( newState ) != PeripheralType.WirelessModem;
     }
 
-    @Override
-    public void getDroppedItems( @Nonnull NonNullList<ItemStack> drops, boolean creative )
-    {
-        if( !creative ) drops.add( PeripheralItemFactory.create( PeripheralType.WirelessModem, null, 1 ) );
-    }
-
     @Override
     public PeripheralType getPeripheralType()
     {

src/main/java/dan200/computercraft/shared/peripheral/modem/wireless/TileWirelessModemBase.java

@@ -22,13 +22,18 @@ import javax.annotation.Nonnull;
 
 public abstract class TileWirelessModemBase extends TileGeneric implements IPeripheralTile
 {
+    protected TileWirelessModemBase( boolean advanced )
+    {
+        this.advanced = advanced;
+    }
+
     private static class Peripheral extends WirelessModemPeripheral
     {
         private final TileWirelessModemBase entity;
 
         Peripheral( TileWirelessModemBase entity )
         {
-            super( new ModemState( () -> TickScheduler.schedule( entity ) ), true );
+            super( new ModemState( () -> TickScheduler.schedule( entity ) ), entity.advanced );
             this.entity = entity;
         }
 
@@ -54,6 +59,7 @@ public abstract class TileWirelessModemBase extends TileGeneric implements IPeri
         }
     }
 
+    private final boolean advanced;
     private boolean hasModemDirection = false;
     private EnumFacing modemDirection = EnumFacing.DOWN;
     private final ModemPeripheral modem = new Peripheral( this );
@@ -115,13 +121,13 @@ public abstract class TileWirelessModemBase extends TileGeneric implements IPeri
     protected abstract EnumFacing getDirection();
 
     @Override
-    public void onNeighbourChange()
+    public void onNeighbourChange( @Nonnull BlockPos neighbour )
     {
         EnumFacing dir = getDirection();
-        if( !getWorld().isSideSolid( getPos().offset( dir ), dir.getOpposite() ) )
+        if( neighbour.equals( getPos().offset( dir ) ) && !getWorld().isSideSolid( neighbour, dir.getOpposite() ) )
         {
             // Drop everything and remove block
-            getBlock().dropAllItems( getWorld(), getPos(), false );
+            getBlock().dropBlockAsItem( getWorld(), getPos(), getBlockState(), 0 );
             getWorld().setBlockToAir( getPos() );
         }
     }

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

@@ -28,8 +28,6 @@ public class MonitorPeripheral implements IPeripheral
         m_monitor = monitor;
     }
 
-    // IPeripheral implementation
-
     @Nonnull
     @Override
     public String getType()

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

@@ -16,27 +16,23 @@ import dan200.computercraft.shared.peripheral.PeripheralType;
 import dan200.computercraft.shared.peripheral.common.BlockPeripheral;
 import dan200.computercraft.shared.peripheral.common.IPeripheralTile;
 import dan200.computercraft.shared.peripheral.common.ITilePeripheral;
-import dan200.computercraft.shared.peripheral.common.PeripheralItemFactory;
 import net.minecraft.block.state.IBlockState;
 import net.minecraft.entity.player.EntityPlayer;
-import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.NBTTagCompound;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.EnumFacing;
 import net.minecraft.util.EnumHand;
-import net.minecraft.util.NonNullList;
 import net.minecraft.util.math.AxisAlignedBB;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.World;
 
 import javax.annotation.Nonnull;
-import java.util.HashSet;
+import java.util.Collections;
 import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
 
 public class TileMonitor extends TileGeneric implements ITilePeripheral, IPeripheralTile
 {
-    // Statics
-
     public static final double RENDER_BORDER = (2.0 / 16.0);
     public static final double RENDER_MARGIN = (0.5 / 16.0);
     public static final double RENDER_PIXEL_SCALE = (1.0 / 64.0);
@@ -44,39 +40,23 @@ public class TileMonitor extends TileGeneric implements ITilePeripheral, IPeriph
     private static final int MAX_WIDTH = 8;
     private static final int MAX_HEIGHT = 6;
 
-    // Members
     private ServerMonitor m_serverMonitor;
     private ClientMonitor m_clientMonitor;
     private MonitorPeripheral m_peripheral;
-    private final Set<IComputerAccess> m_computers;
+    private final Set<IComputerAccess> m_computers = Collections.newSetFromMap( new ConcurrentHashMap<>() );
 
-    private boolean m_destroyed;
-    private boolean m_ignoreMe;
+    private boolean m_destroyed = false;
+    private boolean m_ignoreMe = false;
 
-    private int m_width;
-    private int m_height;
-    private int m_xIndex;
-    private int m_yIndex;
+    private int m_width = 1;
+    private int m_height = 1;
+    private int m_xIndex = 0;
+    private int m_yIndex = 0;
 
-    private int m_dir;
+    private int m_dir = 2;
 
     private boolean m_advanced;
 
-    public TileMonitor()
-    {
-        m_computers = new HashSet<>();
-
-        m_destroyed = false;
-        m_ignoreMe = false;
-
-        m_width = 1;
-        m_height = 1;
-        m_xIndex = 0;
-        m_yIndex = 0;
-
-        m_dir = 2;
-    }
-
     @Override
     public void onLoad()
     {
@@ -697,20 +677,14 @@ public class TileMonitor extends TileGeneric implements ITilePeripheral, IPeriph
         }
     }
 
-    public void addComputer( IComputerAccess computer )
+    void addComputer( IComputerAccess computer )
     {
-        synchronized( this )
-        {
-            m_computers.add( computer );
-        }
+        m_computers.add( computer );
     }
 
-    public void removeComputer( IComputerAccess computer )
+    void removeComputer( IComputerAccess computer )
     {
-        synchronized( this )
-        {
-            m_computers.remove( computer );
-        }
+        m_computers.remove( computer );
     }
 
     @Nonnull
@@ -757,10 +731,4 @@ public class TileMonitor extends TileGeneric implements ITilePeripheral, IPeriph
             }
         }
     }
-
-    @Override
-    public void getDroppedItems( @Nonnull NonNullList<ItemStack> drops, boolean creative )
-    {
-        if( !creative ) drops.add( PeripheralItemFactory.create( this ) );
-    }
 }

src/main/java/dan200/computercraft/shared/turtle/blocks/BlockTurtle.java

@@ -27,7 +27,6 @@ import net.minecraft.util.EnumBlockRenderType;
 import net.minecraft.util.EnumFacing;
 import net.minecraft.util.math.AxisAlignedBB;
 import net.minecraft.util.math.BlockPos;
-import net.minecraft.util.math.RayTraceResult;
 import net.minecraft.util.math.Vec3d;
 import net.minecraft.world.IBlockAccess;
 import net.minecraft.world.World;
@@ -200,11 +199,10 @@ public class BlockTurtle extends BlockComputerBase
         return super.getExplosionResistance( exploder );
     }
 
-    @Override
     @Nonnull
-    public ItemStack getPickBlock( @Nonnull IBlockState state, RayTraceResult target, @Nonnull World world, @Nonnull BlockPos pos, EntityPlayer player )
+    @Override
+    protected ItemStack getItem( TileComputerBase tile )
     {
-        TileEntity tile = world.getTileEntity( pos );
-        return tile instanceof TileTurtle ? TurtleItemFactory.create( (TileTurtle) tile ) : super.getPickBlock( state, target, world, pos, player );
+        return tile instanceof TileTurtle ? TurtleItemFactory.create( (TileTurtle) tile ) : ItemStack.EMPTY;
     }
 }

src/main/java/dan200/computercraft/shared/turtle/blocks/TileTurtle.java

@@ -17,7 +17,6 @@ import dan200.computercraft.shared.computer.core.ComputerFamily;
 import dan200.computercraft.shared.computer.core.ServerComputer;
 import dan200.computercraft.shared.turtle.apis.TurtleAPI;
 import dan200.computercraft.shared.turtle.core.TurtleBrain;
-import dan200.computercraft.shared.turtle.items.TurtleItemFactory;
 import dan200.computercraft.shared.util.DefaultInventory;
 import dan200.computercraft.shared.util.InventoryUtil;
 import dan200.computercraft.shared.util.RedstoneUtil;
@@ -166,12 +165,6 @@ public class TileTurtle extends TileComputerBase implements ITurtleTile, Default
         }
     }
 
-    @Override
-    public void getDroppedItems( @Nonnull NonNullList<ItemStack> drops, boolean creative )
-    {
-        if( !creative || getLabel() != null ) drops.add( TurtleItemFactory.create( this ) );
-    }
-
     @Override
     public boolean onActivate( EntityPlayer player, EnumHand hand, EnumFacing side, float hitX, float hitY, float hitZ )
     {
@@ -262,38 +255,26 @@ public class TileTurtle extends TileComputerBase implements ITurtleTile, Default
     }
 
     @Override
-    public void onNeighbourChange()
+    public void onNeighbourChange( @Nonnull BlockPos neighbour )
     {
-        if( m_moveState == MoveState.NOT_MOVED )
-        {
-            super.onNeighbourChange();
-        }
+        if( m_moveState == MoveState.NOT_MOVED ) super.onNeighbourChange( neighbour );
     }
 
     @Override
     public void onNeighbourTileEntityChange( @Nonnull BlockPos neighbour )
     {
-        if( m_moveState == MoveState.NOT_MOVED )
-        {
-            super.onNeighbourTileEntityChange( neighbour );
-        }
+        if( m_moveState == MoveState.NOT_MOVED ) super.onNeighbourTileEntityChange( neighbour );
     }
 
     public void notifyMoveStart()
     {
-        if( m_moveState == MoveState.NOT_MOVED )
-        {
-            m_moveState = MoveState.IN_PROGRESS;
-        }
+        if( m_moveState == MoveState.NOT_MOVED ) m_moveState = MoveState.IN_PROGRESS;
     }
 
     public void notifyMoveEnd()
     {
         // MoveState.MOVED is final
-        if( m_moveState == MoveState.IN_PROGRESS )
-        {
-            m_moveState = MoveState.NOT_MOVED;
-        }
+        if( m_moveState == MoveState.IN_PROGRESS ) m_moveState = MoveState.NOT_MOVED;
     }
 
     @Override

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

@@ -13,6 +13,7 @@ import dan200.computercraft.api.lua.ILuaContext;
 import dan200.computercraft.api.lua.LuaException;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import dan200.computercraft.api.turtle.*;
+import dan200.computercraft.core.tracking.Tracking;
 import dan200.computercraft.shared.computer.blocks.ComputerProxy;
 import dan200.computercraft.shared.computer.blocks.TileComputerBase;
 import dan200.computercraft.shared.computer.core.ComputerFamily;
@@ -972,17 +973,21 @@ public class TurtleBrain implements ITurtleAccess
             TurtleCommandQueueEntry nextCommand = m_commandQueue.poll();
             if( nextCommand != null )
             {
+                ServerComputer computer = m_owner.getServerComputer();
+
                 // Execute the command
+                long start = System.nanoTime();
                 TurtleCommandResult result = nextCommand.command.execute( this );
+                long end = System.nanoTime();
 
                 // Dispatch the callback
-                int callbackID = nextCommand.callbackID;
-                if( callbackID >= 0 )
+                if( computer != null )
                 {
-                    if( result != null && result.isSuccess() )
+                    Tracking.addServerTiming( computer.getComputer(), end - start );
+                    int callbackID = nextCommand.callbackID;
+                    if( callbackID >= 0 )
                     {
-                        ServerComputer computer = m_owner.getServerComputer();
-                        if( computer != null )
+                        if( result != null && result.isSuccess() )
                         {
                             Object[] results = result.getResults();
                             if( results != null )
@@ -1000,11 +1005,7 @@ public class TurtleBrain implements ITurtleAccess
                                 } );
                             }
                         }
-                    }
-                    else
-                    {
-                        ServerComputer computer = m_owner.getServerComputer();
-                        if( computer != null )
+                        else
                         {
                             computer.queueEvent( "turtle_response", new Object[] {
                                 callbackID, false, result != null ? result.getErrorMessage() : null

src/main/java/dan200/computercraft/shared/util/RedstoneUtil.java

@@ -18,7 +18,7 @@ public class RedstoneUtil
     @Deprecated
     public static int getRedstoneOutput( World world, BlockPos pos, EnumFacing side )
     {
-        return world.getRedstonePower( pos, side );
+        return world.getRedstonePower( pos, side.getOpposite() );
     }
 
     @Deprecated

src/main/resources/assets/computercraft/lua/rom/programs/shell.lua

@@ -63,7 +63,7 @@ local function createShellEnv( sDir )
                     end
                 else
                     if #sError > 0 then
-                        sError = sError .. "\n"
+                        sError = sError .. "\n  "
                     end
                     sError = sError .. "no file '" .. sPath .. "'"
                 end
@@ -78,27 +78,24 @@ local function createShellEnv( sDir )
             error( "bad argument #1 (expected string, got " .. type( name ) .. ")", 2 )
         end
         if package.loaded[name] == sentinel then
-            error("Loop detected requiring '" .. name .. "'", 0)
+            error("loop or previous error loading module '" .. name .. "'", 0)
         end
         if package.loaded[name] then
             return package.loaded[name]
         end
 
-        local sError = "Error loading module '" .. name .. "':"
-        for n,searcher in ipairs(package.loaders) do
-            local loader, err = searcher(name)
-            if loader then
+        local sError = "module '" .. name .. "' not found:"
+        for _, searcher in ipairs(package.loaders) do
+            local loader = table.pack(searcher(name))
+            if loader[1] then
                 package.loaded[name] = sentinel
-                local result = loader( err )
-                if result ~= nil then
-                    package.loaded[name] = result
-                    return result
-                else
-                    package.loaded[name] = true
-                    return true
-                end
+                local result = loader[1](name, table.unpack(loader, 2, loader.n))
+                if result == nil then result = true end
+
+                package.loaded[name] = result
+                return result
             else
-                sError = sError .. "\n" .. err
+                sError = sError .. "\n  " .. loader[2]
             end
         end
         error(sError, 2)