diff --git a/src/main/scala/li/cil/oc/common/block/Assembler.scala b/src/main/scala/li/cil/oc/common/block/Assembler.scala
index f90fecd44..9b8c08cc3 100644
--- a/src/main/scala/li/cil/oc/common/block/Assembler.scala
+++ b/src/main/scala/li/cil/oc/common/block/Assembler.scala
@@ -42,6 +42,16 @@ class Assembler extends SimpleBlock with traits.SpecialBlock with traits.PowerAc
 
   // ----------------------------------------------------------------------- //
 
+  override def hasComparatorInputOverride = true
+
+  override def getComparatorInputOverride(world: World, x: Int, y: Int, z: Int, side: Int) =
+    world.getTileEntity(x, y, z) match {
+      case assembler: tileentity.Assembler if assembler.isAssembling => 15
+      case _ => 0
+    }
+
+  // ----------------------------------------------------------------------- //
+
   override def onBlockActivated(world: World, x: Int, y: Int, z: Int, player: EntityPlayer,
                                 side: ForgeDirection, hitX: Float, hitY: Float, hitZ: Float) = {
     if (!player.isSneaking) {
diff --git a/src/main/scala/li/cil/oc/common/block/Case.scala b/src/main/scala/li/cil/oc/common/block/Case.scala
index befdbed56..e374b714e 100644
--- a/src/main/scala/li/cil/oc/common/block/Case.scala
+++ b/src/main/scala/li/cil/oc/common/block/Case.scala
@@ -77,6 +77,16 @@ class Case(val tier: Int) extends RedstoneAware with traits.PowerAcceptor {
 
   // ----------------------------------------------------------------------- //
 
+  override def hasComparatorInputOverride = true
+
+  override def getComparatorInputOverride(world: World, x: Int, y: Int, z: Int, side: Int) =
+    world.getTileEntity(x, y, z) match {
+      case computer: tileentity.Case if computer.isRunning => 15
+      case _ => 0
+    }
+
+  // ----------------------------------------------------------------------- //
+
   override def onBlockActivated(world: World, x: Int, y: Int, z: Int, player: EntityPlayer,
                                 side: ForgeDirection, hitX: Float, hitY: Float, hitZ: Float) = {
     if (!player.isSneaking && !Wrench.holdsApplicableWrench(player, BlockPosition(x, y, z))) {
diff --git a/src/main/scala/li/cil/oc/common/block/Disassembler.scala b/src/main/scala/li/cil/oc/common/block/Disassembler.scala
index cfcb2b496..53a685f83 100644
--- a/src/main/scala/li/cil/oc/common/block/Disassembler.scala
+++ b/src/main/scala/li/cil/oc/common/block/Disassembler.scala
@@ -44,6 +44,16 @@ class Disassembler extends SimpleBlock with traits.PowerAcceptor {
 
   // ----------------------------------------------------------------------- //
 
+  override def hasComparatorInputOverride = true
+
+  override def getComparatorInputOverride(world: World, x: Int, y: Int, z: Int, side: Int) =
+    world.getTileEntity(x, y, z) match {
+      case disassembler: tileentity.Disassembler if disassembler.isActive => 15
+      case _ => 0
+    }
+
+  // ----------------------------------------------------------------------- //
+
   override def onBlockActivated(world: World, x: Int, y: Int, z: Int, player: EntityPlayer,
                                 side: ForgeDirection, hitX: Float, hitY: Float, hitZ: Float) = {
     if (!player.isSneaking) {
diff --git a/src/main/scala/li/cil/oc/common/block/DiskDrive.scala b/src/main/scala/li/cil/oc/common/block/DiskDrive.scala
index a5905dc2c..7281c625c 100644
--- a/src/main/scala/li/cil/oc/common/block/DiskDrive.scala
+++ b/src/main/scala/li/cil/oc/common/block/DiskDrive.scala
@@ -37,6 +37,16 @@ class DiskDrive extends SimpleBlock {
 
   // ----------------------------------------------------------------------- //
 
+  override def hasComparatorInputOverride = true
+
+  override def getComparatorInputOverride(world: World, x: Int, y: Int, z: Int, side: Int) =
+    world.getTileEntity(x, y, z) match {
+      case drive: tileentity.DiskDrive if drive.getStackInSlot(0) != null => 15
+      case _ => 0
+    }
+
+  // ----------------------------------------------------------------------- //
+
   override def onBlockActivated(world: World, x: Int, y: Int, z: Int, player: EntityPlayer,
                                 side: ForgeDirection, hitX: Float, hitY: Float, hitZ: Float) = {
     world.getTileEntity(x, y, z) match {
diff --git a/src/main/scala/li/cil/oc/common/block/Microcontroller.scala b/src/main/scala/li/cil/oc/common/block/Microcontroller.scala
index f5e6544f0..b499078f2 100644
--- a/src/main/scala/li/cil/oc/common/block/Microcontroller.scala
+++ b/src/main/scala/li/cil/oc/common/block/Microcontroller.scala
@@ -63,6 +63,16 @@ class Microcontroller extends RedstoneAware with traits.PowerAcceptor {
 
   // ----------------------------------------------------------------------- //
 
+  override def hasComparatorInputOverride = true
+
+  override def getComparatorInputOverride(world: World, x: Int, y: Int, z: Int, side: Int) =
+    world.getTileEntity(x, y, z) match {
+      case computer: tileentity.Microcontroller if computer.isRunning => 15
+      case _ => 0
+    }
+
+  // ----------------------------------------------------------------------- //
+
   override def onBlockActivated(world: World, x: Int, y: Int, z: Int, player: EntityPlayer,
                                 side: ForgeDirection, hitX: Float, hitY: Float, hitZ: Float) = {
     if (!player.isSneaking && !Wrench.holdsApplicableWrench(player, BlockPosition(x, y, z))) {
diff --git a/src/main/scala/li/cil/oc/common/block/Raid.scala b/src/main/scala/li/cil/oc/common/block/Raid.scala
index 84d7c6de5..1b47e6c08 100644
--- a/src/main/scala/li/cil/oc/common/block/Raid.scala
+++ b/src/main/scala/li/cil/oc/common/block/Raid.scala
@@ -25,6 +25,16 @@ class Raid extends SimpleBlock {
 
   // ----------------------------------------------------------------------- //
 
+  override def hasComparatorInputOverride = true
+
+  override def getComparatorInputOverride(world: World, x: Int, y: Int, z: Int, side: Int) =
+    world.getTileEntity(x, y, z) match {
+      case raid: tileentity.Raid if raid.presence.forall(ok => ok) => 15
+      case _ => 0
+    }
+
+  // ----------------------------------------------------------------------- //
+
   override def onBlockActivated(world: World, x: Int, y: Int, z: Int, player: EntityPlayer,
                                 side: ForgeDirection, hitX: Float, hitY: Float, hitZ: Float) = {
     world.getTileEntity(x, y, z) match {
diff --git a/src/main/scala/li/cil/oc/common/block/RobotProxy.scala b/src/main/scala/li/cil/oc/common/block/RobotProxy.scala
index ba0dad2ff..e697d574d 100644
--- a/src/main/scala/li/cil/oc/common/block/RobotProxy.scala
+++ b/src/main/scala/li/cil/oc/common/block/RobotProxy.scala
@@ -115,6 +115,16 @@ class RobotProxy extends RedstoneAware with traits.SpecialBlock {
 
   // ----------------------------------------------------------------------- //
 
+  override def hasComparatorInputOverride = true
+
+  override def getComparatorInputOverride(world: World, x: Int, y: Int, z: Int, side: Int) =
+    world.getTileEntity(x, y, z) match {
+      case proxy: tileentity.RobotProxy if proxy.isRunning => 15
+      case _ => 0
+    }
+
+  // ----------------------------------------------------------------------- //
+
   override def getExplosionResistance(entity: Entity) = 10f
 
   override def getDrops(world: World, x: Int, y: Int, z: Int, metadata: Int, fortune: Int) = {
diff --git a/src/main/scala/li/cil/oc/common/block/ServerRack.scala b/src/main/scala/li/cil/oc/common/block/ServerRack.scala
index fce487c37..ed374df2e 100644
--- a/src/main/scala/li/cil/oc/common/block/ServerRack.scala
+++ b/src/main/scala/li/cil/oc/common/block/ServerRack.scala
@@ -53,6 +53,16 @@ class ServerRack extends RedstoneAware with traits.SpecialBlock with traits.Powe
 
   // ----------------------------------------------------------------------- //
 
+  override def hasComparatorInputOverride = true
+
+  override def getComparatorInputOverride(world: World, x: Int, y: Int, z: Int, side: Int) =
+    world.getTileEntity(x, y, z) match {
+      case rack: tileentity.ServerRack if rack.anyRunning => 15
+      case _ => 0
+    }
+
+  // ----------------------------------------------------------------------- //
+
   override def onBlockActivated(world: World, x: Int, y: Int, z: Int, player: EntityPlayer,
                                 side: ForgeDirection, hitX: Float, hitY: Float, hitZ: Float) = {
     if (!player.isSneaking) {
diff --git a/src/main/scala/li/cil/oc/common/tileentity/Disassembler.scala b/src/main/scala/li/cil/oc/common/tileentity/Disassembler.scala
index a91f564a2..a7b6304df 100644
--- a/src/main/scala/li/cil/oc/common/tileentity/Disassembler.scala
+++ b/src/main/scala/li/cil/oc/common/tileentity/Disassembler.scala
@@ -36,6 +36,7 @@ class Disassembler extends traits.Environment with traits.PowerAcceptor with tra
   private def setActive(value: Boolean) = if (value != isActive) {
     isActive = value
     ServerPacketSender.sendDisassemblerActive(this, isActive)
+    world.notifyBlocksOfNeighborChange(x, y, z, block)
   }
 
   // ----------------------------------------------------------------------- //
diff --git a/src/main/scala/li/cil/oc/common/tileentity/ServerRack.scala b/src/main/scala/li/cil/oc/common/tileentity/ServerRack.scala
index caf9e8124..7c6ef69b5 100644
--- a/src/main/scala/li/cil/oc/common/tileentity/ServerRack.scala
+++ b/src/main/scala/li/cil/oc/common/tileentity/ServerRack.scala
@@ -279,6 +279,7 @@ class ServerRack extends traits.PowerAcceptor with traits.Hub with traits.PowerB
         if (_isRunning(i) != isRunning) {
           _isRunning(i) = isRunning
           ServerPacketSender.sendServerState(this, i)
+          world.notifyBlocksOfNeighborChange(x, y, z, block)
         }
       }
       isOutputEnabled = hasRedstoneCard