diff --git a/app/src/main/kotlin/android/emu6502/CPU.kt b/app/src/main/kotlin/android/emu6502/CPU.kt
index a5d657a..e46103e 100644
--- a/app/src/main/kotlin/android/emu6502/CPU.kt
+++ b/app/src/main/kotlin/android/emu6502/CPU.kt
@@ -14,7 +14,7 @@ import java.util.concurrent.CountDownLatch
 class CPU(val memory: Memory) : Display.Callbacks {
   private val bgHandlerThread = HandlerThread("Screencast Thread")
   private val bgHandler: Handler
-  private var lock: CountDownLatch? = null
+  private var executionLock: CountDownLatch? = null
 
   init {
     bgHandlerThread.start()
@@ -36,7 +36,7 @@ class CPU(val memory: Memory) : Display.Callbacks {
   private var debug = false
   private var monitoring = false
   private var TAG = "CPU"
-  val instructionList: HashMap<Int, InstructionTarget> = HashMap()
+  private val instructionList: HashMap<Int, InstructionTarget> = HashMap()
   private val operationList: HashMap<Instruction, BaseInstruction> = hashMapOf(
       Pair(Instruction.ADC, ADC(this)),
       Pair(Instruction.AND, AND(this)),
@@ -72,30 +72,44 @@ class CPU(val memory: Memory) : Display.Callbacks {
       Pair(Instruction.SBC, SBC(this)),
       Pair(Instruction.BCC, BCC(this)),
       Pair(Instruction.DEC, DEC(this))
-//      Pair(Instruction.BMI, BMI(this)),
-//      Pair(Instruction.BVC, BVC(this)),
-//      Pair(Instruction.BVS, BVS(this)),
-//      Pair(Instruction.CPY, CPY(this)),
-//      Pair(Instruction.EOR, EOR(this)),
-//      Pair(Instruction.CLI, CLI(this)),
-//      Pair(Instruction.CLV, CLV(this)),
-//      Pair(Instruction.CLD, CLD(this)),
-//      Pair(Instruction.SED, SED(this)),
-//      Pair(Instruction.TAY, TAY(this)),
-//      Pair(Instruction.TYA, TYA(this)),
-//      Pair(Instruction.INY, INY(this)),
-//      Pair(Instruction.ROR, ROR(this)),
-//      Pair(Instruction.ROL, ROL(this)),
-//      Pair(Instruction.RTI, RTI(this)),
-//      Pair(Instruction.TXS, TXS(this)),
-//      Pair(Instruction.TSX, TSX(this)),
-//      Pair(Instruction.PHA, PHA(this)),
-//      Pair(Instruction.PLA, PLA(this)),
-//      Pair(Instruction.PHP, PHP(this)),
-//      Pair(Instruction.PLP, PLP(this)),
-//      Pair(Instruction.STY, STY(this))
+      //Pair(Instruction.BMI, BMI(this)),
+      //Pair(Instruction.BVC, BVC(this)),
+      //Pair(Instruction.BVS, BVS(this)),
+      //Pair(Instruction.CPY, CPY(this)),
+      //Pair(Instruction.EOR, EOR(this)),
+      //Pair(Instruction.CLI, CLI(this)),
+      //Pair(Instruction.CLV, CLV(this)),
+      //Pair(Instruction.CLD, CLD(this)),
+      //Pair(Instruction.SED, SED(this)),
+      //Pair(Instruction.TAY, TAY(this)),
+      //Pair(Instruction.TYA, TYA(this)),
+      //Pair(Instruction.INY, INY(this)),
+      //Pair(Instruction.ROR, ROR(this)),
+      //Pair(Instruction.ROL, ROL(this)),
+      //Pair(Instruction.RTI, RTI(this)),
+      //Pair(Instruction.TXS, TXS(this)),
+      //Pair(Instruction.TSX, TSX(this)),
+      //Pair(Instruction.PHA, PHA(this)),
+      //Pair(Instruction.PLA, PLA(this)),
+      //Pair(Instruction.PHP, PHP(this)),
+      //Pair(Instruction.PLP, PLP(this)),
+      //Pair(Instruction.STY, STY(this))
   )
 
+  // for testing only
+  fun testRun() {
+    isRunning = true
+    while (true) {
+      setRandomByte()
+      executeNextInstruction()
+
+      if (PC == 0 || !isRunning) {
+        break
+      }
+    }
+    stop()
+  }
+
   fun run() {
     isRunning = true
     bgHandler.post { innerRun() }
@@ -155,7 +169,11 @@ class CPU(val memory: Memory) : Display.Callbacks {
     P = 0x30
   }
 
-   fun popByte(): Int {
+  fun addInstruction(opcode: Int, target: InstructionTarget) {
+    instructionList.put(opcode, target)
+  }
+
+  fun popByte(): Int {
     return memory.get(PC++).and(0xff)
   }
 
@@ -297,11 +315,11 @@ class CPU(val memory: Memory) : Display.Callbacks {
   }
 
   override fun onUpdate() {
-    lock = CountDownLatch(1)
-    lock?.await()
+    executionLock = CountDownLatch(1)
+    executionLock?.await()
   }
 
   override fun onDraw() {
-    lock?.countDown()
+    executionLock?.countDown()
   }
 }
\ No newline at end of file
diff --git a/app/src/main/kotlin/android/emu6502/instructions/BaseInstruction.kt b/app/src/main/kotlin/android/emu6502/instructions/BaseInstruction.kt
index 6e43e38..59779b8 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/BaseInstruction.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/BaseInstruction.kt
@@ -1,9 +1,8 @@
 package android.emu6502.instructions
 
-import java.util.HashMap
+import android.emu6502.CPU
 
-open class BaseInstruction(val instruction: Instruction,
-    private val instructionList: HashMap<Int, InstructionTarget>) {
+open class BaseInstruction(val instruction: Instruction, private val cpu: CPU) {
 
   init {
     val opcodes: IntArray = Opcodes.MAP[instruction] as IntArray
@@ -12,7 +11,7 @@ open class BaseInstruction(val instruction: Instruction,
 
     opcodes.forEachIndexed { i, opcode ->
       if (opcode != 0xff) {
-        instructionList.put(opcodes[i], InstructionTarget(this, methods[i]))
+        cpu.addInstruction(opcodes[i], InstructionTarget(this, methods[i]))
       }
     }
   }
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/ADC.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/ADC.kt
index d48934a..0cd972b 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/ADC.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/ADC.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** ADd with Carry */
-class ADC(private val cpu: CPU) : BaseInstruction(Instruction.ADC, cpu.instructionList) {
+class ADC(private val cpu: CPU) : BaseInstruction(Instruction.ADC, cpu) {
   override fun immediate() {
     testADC(cpu.popByte())
   }
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/AND.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/AND.kt
index a6fc33f..83adca3 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/AND.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/AND.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** bitwise AND with accumulator */
-class AND(private val cpu: CPU) : BaseInstruction(Instruction.AND, cpu.instructionList) {
+class AND(private val cpu: CPU) : BaseInstruction(Instruction.AND, cpu) {
   override fun immediate() {
     cpu.A = cpu.A.and(cpu.popByte())
     cpu.setSZFlagsForRegA()
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/ASL.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/ASL.kt
index bc93889..d37ea0b 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/ASL.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/ASL.kt
@@ -5,5 +5,5 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** Arithmetic Shift Left */
-class ASL(private val cpu: CPU) : BaseInstruction(Instruction.ASL, cpu.instructionList) {
+class ASL(private val cpu: CPU) : BaseInstruction(Instruction.ASL, cpu) {
 }
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/BCC.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/BCC.kt
index 737a274..5b79cdb 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/BCC.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/BCC.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** Branch on Carry Clear */
-final class BCC(private val cpu: CPU) : BaseInstruction(Instruction.BCC, cpu.instructionList) {
+final class BCC(private val cpu: CPU) : BaseInstruction(Instruction.BCC, cpu) {
   override fun branch() {
     val offset = cpu.popByte()
     if (!cpu.carry()) {
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/BCS.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/BCS.kt
index b2d385f..70f66e0 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/BCS.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/BCS.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** Branch on Carry Set */
-final class BCS(private val cpu: CPU) : BaseInstruction(Instruction.BCS, cpu.instructionList) {
+final class BCS(private val cpu: CPU) : BaseInstruction(Instruction.BCS, cpu) {
   override fun branch() {
     val offset = cpu.popByte()
     if (cpu.carry()) {
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/BEQ.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/BEQ.kt
index f730173..4048574 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/BEQ.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/BEQ.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** Branch on EQual */
-class BEQ(private val cpu: CPU) : BaseInstruction(Instruction.BEQ, cpu.instructionList) {
+class BEQ(private val cpu: CPU) : BaseInstruction(Instruction.BEQ, cpu) {
   override fun branch() {
     val offset = cpu.popByte()
     if (cpu.zero()) {
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/BIT.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/BIT.kt
index 4a412cc..b93c845 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/BIT.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/BIT.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** test BITs */
-class BIT(private val cpu: CPU) : BaseInstruction(Instruction.BIT, cpu.instructionList) {
+class BIT(private val cpu: CPU) : BaseInstruction(Instruction.BIT, cpu) {
   override fun zeroPage() {
     val value = cpu.memory.get(cpu.popByte())
     BIT(value)
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/BNE.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/BNE.kt
index fe30e84..593a023 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/BNE.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/BNE.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** Branch on Not Equal */
-final class BNE(private val cpu: CPU) : BaseInstruction(Instruction.BNE, cpu.instructionList) {
+final class BNE(private val cpu: CPU) : BaseInstruction(Instruction.BNE, cpu) {
   override fun branch() {
     val offset = cpu.popByte()
     if (!cpu.zero()) {
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/BPL.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/BPL.kt
index e24341d..3caa910 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/BPL.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/BPL.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** Branch on PLus */
-final class BPL(private val cpu: CPU) : BaseInstruction(Instruction.BPL, cpu.instructionList) {
+final class BPL(private val cpu: CPU) : BaseInstruction(Instruction.BPL, cpu) {
   override fun branch() {
     val offset = cpu.popByte()
     if (!cpu.negative()) {
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/BRK.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/BRK.kt
index 8241556..c35b8d5 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/BRK.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/BRK.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** BRreaK */
-final class BRK(private val cpu: CPU) : BaseInstruction(Instruction.BRK, cpu.instructionList) {
+final class BRK(private val cpu: CPU) : BaseInstruction(Instruction.BRK, cpu) {
   override fun single() {
     cpu.stop()
   }
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/CLC.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/CLC.kt
index 8075a34..7eef840 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/CLC.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/CLC.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** CLear Carry */
-final class CLC(private val cpu: CPU) : BaseInstruction(Instruction.CLC, cpu.instructionList) {
+final class CLC(private val cpu: CPU) : BaseInstruction(Instruction.CLC, cpu) {
   override fun single() {
     cpu.CLC()
   }
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/CMP.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/CMP.kt
index f864405..778211e 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/CMP.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/CMP.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** CoMPare accumulator */
-final class CMP(private val cpu: CPU) : BaseInstruction(Instruction.CMP, cpu.instructionList) {
+final class CMP(private val cpu: CPU) : BaseInstruction(Instruction.CMP, cpu) {
   override fun immediate() {
     cpu.doCompare(cpu.A, cpu.popByte())
   }
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/CPX.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/CPX.kt
index b080287..10343b4 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/CPX.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/CPX.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** ComPare X register */
-class CPX(private val cpu: CPU) : BaseInstruction(Instruction.CPX, cpu.instructionList) {
+class CPX(private val cpu: CPU) : BaseInstruction(Instruction.CPX, cpu) {
   override fun immediate() {
     val value = cpu.popByte()
     cpu.doCompare(cpu.X, value)
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/DEC.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/DEC.kt
index 00fa011..d294cd9 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/DEC.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/DEC.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** DECrement memory */
-class DEC(private val cpu: CPU) : BaseInstruction(Instruction.DEC, cpu.instructionList) {
+class DEC(private val cpu: CPU) : BaseInstruction(Instruction.DEC, cpu) {
   override fun zeroPage() {
     DEC(cpu.popByte())
   }
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/DEX.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/DEX.kt
index c5dd738..4601107 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/DEX.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/DEX.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** DEcrement X */
-class DEX(private val cpu: CPU) : BaseInstruction(Instruction.DEX, cpu.instructionList) {
+class DEX(private val cpu: CPU) : BaseInstruction(Instruction.DEX, cpu) {
   override fun single() {
     cpu.X = (cpu.X - 1).and(0xff)
     cpu.setSZflagsForRegX()
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/DEY.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/DEY.kt
index f75dd78..70260e3 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/DEY.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/DEY.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** DEcrement Y */
-class DEY(private val cpu: CPU) : BaseInstruction(Instruction.DEY, cpu.instructionList) {
+class DEY(private val cpu: CPU) : BaseInstruction(Instruction.DEY, cpu) {
   override fun single() {
     cpu.Y = (cpu.Y - 1).and(0xff)
     cpu.setSZflagsForRegY()
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/INC.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/INC.kt
index c1a9b0a..8bf7695 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/INC.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/INC.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** INCrement memory */
-final class INC(private val cpu: CPU) : BaseInstruction(Instruction.INC, cpu.instructionList) {
+final class INC(private val cpu: CPU) : BaseInstruction(Instruction.INC, cpu) {
   override fun zeroPage() {
     inc(cpu.popByte())
   }
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/INX.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/INX.kt
index abd1487..bc904ed 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/INX.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/INX.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** INcrement X */
-class INX(private val cpu: CPU) : BaseInstruction(Instruction.INX, cpu.instructionList) {
+class INX(private val cpu: CPU) : BaseInstruction(Instruction.INX, cpu) {
   override fun single() {
     cpu.X = (cpu.X + 1).and(0xff)
     cpu.setSZflagsForRegX()
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/JMP.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/JMP.kt
index 558ccf2..a0d846a 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/JMP.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/JMP.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** JuMP */
-class JMP(private val cpu: CPU) : BaseInstruction(Instruction.JMP, cpu.instructionList) {
+class JMP(private val cpu: CPU) : BaseInstruction(Instruction.JMP, cpu) {
   override fun absolute() {
     cpu.PC = cpu.popWord()
   }
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/JSR.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/JSR.kt
index 7dc7f03..1d102b9 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/JSR.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/JSR.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** Jump to SubRoutine */
-class JSR(private val cpu: CPU) : BaseInstruction(Instruction.JSR, cpu.instructionList) {
+class JSR(private val cpu: CPU) : BaseInstruction(Instruction.JSR, cpu) {
   override fun absolute() {
     val addr = cpu.popWord()
     val currAddr = cpu.PC - 1
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/LDA.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/LDA.kt
index a2575ad..0a9d1c7 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/LDA.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/LDA.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** LoaD Accumulator */
-class LDA(private val cpu: CPU) : BaseInstruction(Instruction.LDA, cpu.instructionList) {
+class LDA(private val cpu: CPU) : BaseInstruction(Instruction.LDA, cpu) {
   override fun immediate() {
     cpu.A = cpu.popByte()
     cpu.setSZFlagsForRegA()
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/LDX.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/LDX.kt
index 3bf8fcb..34ebd22 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/LDX.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/LDX.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** LoaD X register */
-class LDX(private val cpu: CPU) : BaseInstruction(Instruction.LDX, cpu.instructionList) {
+class LDX(private val cpu: CPU) : BaseInstruction(Instruction.LDX, cpu) {
   override fun immediate() {
     cpu.X = cpu.popByte()
     cpu.setSZflagsForRegX()
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/LDY.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/LDY.kt
index 0b73bb9..cea2a33 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/LDY.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/LDY.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** LoaD Y register */
-class LDY(private val cpu: CPU) : BaseInstruction(Instruction.LDY, cpu.instructionList) {
+class LDY(private val cpu: CPU) : BaseInstruction(Instruction.LDY, cpu) {
   override fun immediate() {
     cpu.Y = cpu.popByte()
     cpu.setSZflagsForRegY()
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/LSR.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/LSR.kt
index 7bbf9a6..d815bdb 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/LSR.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/LSR.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** Logical Shift Right */
-final class LSR(private val cpu: CPU) : BaseInstruction(Instruction.LSR, cpu.instructionList) {
+final class LSR(private val cpu: CPU) : BaseInstruction(Instruction.LSR, cpu) {
   override fun single() {
     cpu.setCarryFlagFromBit0(cpu.A)
     cpu.A = cpu.A.shr(1)
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/NOP.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/NOP.kt
index 49e017a..684af71 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/NOP.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/NOP.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** No OPeration */
-class NOP(private val cpu: CPU) : BaseInstruction(Instruction.NOP, cpu.instructionList) {
+class NOP(private val cpu: CPU) : BaseInstruction(Instruction.NOP, cpu) {
   override fun single() {
   }
 }
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/ORA.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/ORA.kt
index d2a954b..ac83959 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/ORA.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/ORA.kt
@@ -5,5 +5,5 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** bitwise OR with Accumulator */
-class ORA(cpu: CPU) : BaseInstruction(Instruction.ORA, cpu.instructionList) {
+class ORA(cpu: CPU) : BaseInstruction(Instruction.ORA, cpu) {
 }
\ No newline at end of file
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/RTS.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/RTS.kt
index 3bfe56b..e5fe969 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/RTS.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/RTS.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** ReTurn from Subroutine */
-class RTS(private val cpu: CPU) : BaseInstruction(Instruction.RTS, cpu.instructionList) {
+class RTS(private val cpu: CPU) : BaseInstruction(Instruction.RTS, cpu) {
   override fun single() {
     cpu.PC = cpu.stackPop().or(cpu.stackPop().shl(8)) + 1
   }
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/SBC.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/SBC.kt
index f130c39..b2109dd 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/SBC.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/SBC.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** SuBtract with Carry */
-class SBC(private val cpu: CPU) : BaseInstruction(Instruction.SBC, cpu.instructionList) {
+class SBC(private val cpu: CPU) : BaseInstruction(Instruction.SBC, cpu) {
   override fun immediate() {
     testSBC(cpu.popByte())
   }
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/SEC.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/SEC.kt
index adddf14..71fc3a1 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/SEC.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/SEC.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** SEt Carry */
-class SEC(private val cpu: CPU) : BaseInstruction(Instruction.SEC, cpu.instructionList) {
+class SEC(private val cpu: CPU) : BaseInstruction(Instruction.SEC, cpu) {
   override fun single() {
     cpu.carry()
   }
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/SEI.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/SEI.kt
index f3b6b1d..0f17d10 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/SEI.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/SEI.kt
@@ -5,6 +5,6 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** SEt Interrupt */
-class SEI(private val cpu: CPU) : BaseInstruction(Instruction.SEI, cpu.instructionList) {
+class SEI(private val cpu: CPU) : BaseInstruction(Instruction.SEI, cpu) {
 }
 
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/STA.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/STA.kt
index 4b609b4..a2cda78 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/STA.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/STA.kt
@@ -7,7 +7,7 @@ import android.emu6502.instructions.Instruction
 
 /** STore Accumulator */
 class STA(private val memory: Memory, private val cpu: CPU)
-    : BaseInstruction(Instruction.STA, cpu.instructionList) {
+    : BaseInstruction(Instruction.STA, cpu) {
 
   override fun absolute() {
     memory.storeByte(cpu.popWord(), cpu.A)
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/STX.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/STX.kt
index bd06cfc..a20e565 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/STX.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/STX.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** STore X register */
-class STX(private val cpu: CPU) : BaseInstruction(Instruction.STX, cpu.instructionList) {
+class STX(private val cpu: CPU) : BaseInstruction(Instruction.STX, cpu) {
   override fun zeroPage() {
     cpu.memory.storeByte(cpu.popByte(), cpu.X)
   }
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/TAX.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/TAX.kt
index bf51181..ff838e3 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/TAX.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/TAX.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** Transfer A to X */
-class TAX(private val cpu: CPU) : BaseInstruction(Instruction.TAX, cpu.instructionList) {
+class TAX(private val cpu: CPU) : BaseInstruction(Instruction.TAX, cpu) {
   override fun single() {
     cpu.X = cpu.A.and(0xFF)
     cpu.setSZflagsForRegX()
diff --git a/app/src/main/kotlin/android/emu6502/instructions/impl/TXA.kt b/app/src/main/kotlin/android/emu6502/instructions/impl/TXA.kt
index b2be3e7..ee49471 100644
--- a/app/src/main/kotlin/android/emu6502/instructions/impl/TXA.kt
+++ b/app/src/main/kotlin/android/emu6502/instructions/impl/TXA.kt
@@ -5,7 +5,7 @@ import android.emu6502.instructions.BaseInstruction
 import android.emu6502.instructions.Instruction
 
 /** Transfer X to A */
-class TXA(private val cpu: CPU) : BaseInstruction(Instruction.TXA, cpu.instructionList) {
+class TXA(private val cpu: CPU) : BaseInstruction(Instruction.TXA, cpu) {
   override fun single() {
     cpu.A = cpu.X.and(0xff)
     cpu.setSZFlagsForRegA()
diff --git a/app/src/test/java/android/emu6502/CPUTest.java b/app/src/test/java/android/emu6502/CPUTest.java
index fcc5be0..4926fd8 100644
--- a/app/src/test/java/android/emu6502/CPUTest.java
+++ b/app/src/test/java/android/emu6502/CPUTest.java
@@ -34,7 +34,7 @@ public class CPUTest {
         "LDA #$08",
         "STA $0202");
     assembler.assembleCode(lines);
-    cpu.run();
+    cpu.testRun();
     assertThat(cpu.getA(), equalTo(0x08));
     assertThat(cpu.getX(), equalTo(0x00));
     assertThat(cpu.getY(), equalTo(0x00));
@@ -51,7 +51,7 @@ public class CPUTest {
         "ADC #$c4  ;Add the hex value $c4 to the A register",
         "BRK       ;Break - we're done");
     assembler.assembleCode(lines);
-    cpu.run();
+    cpu.testRun();
     assertThat(cpu.getA(), equalTo(0x84));
     assertThat(cpu.getX(), equalTo(0xC1));
     assertThat(cpu.getY(), equalTo(0x00));
@@ -72,7 +72,7 @@ public class CPUTest {
         "STX $0201",
         "BRK");
     assembler.assembleCode(lines);
-    cpu.run();
+    cpu.testRun();
     assertThat(cpu.getA(), equalTo(0x00));
     assertThat(cpu.getX(), equalTo(0x03));
     assertThat(cpu.getY(), equalTo(0x00));
@@ -92,7 +92,7 @@ public class CPUTest {
         "there:",
         "STA $0200");
     assembler.assembleCode(lines);
-    cpu.run();
+    cpu.testRun();
     assertThat(cpu.getA(), equalTo(0x03));
     assertThat(cpu.getX(), equalTo(0x00));
     assertThat(cpu.getY(), equalTo(0x00));
@@ -120,7 +120,7 @@ public class CPUTest {
         "end:",
         "BRK");
     assembler.assembleCode(lines);
-    cpu.run();
+    cpu.testRun();
     assertThat(cpu.getA(), equalTo(0x00));
     assertThat(cpu.getX(), equalTo(0x05));
     assertThat(cpu.getY(), equalTo(0x00));
@@ -134,7 +134,7 @@ public class CPUTest {
         "define a_dozen $0c ; a constant",
         "LDX #a_dozen       ; equivalent to \"LDX #$0c\"");
     assembler.assembleCode(lines);
-    cpu.run();
+    cpu.testRun();
     assertThat(cpu.getA(), equalTo(0x00));
     assertThat(cpu.getX(), equalTo(0x0C));
     assertThat(cpu.getY(), equalTo(0x00));
@@ -372,7 +372,7 @@ public class CPUTest {
         "  rts",
         "gameOver:", "\n");
     assembler.assembleCode(lines);
-    cpu.run();
+    cpu.testRun();
     assertThat(cpu.getA(), equalTo(0x1f));
     assertThat(cpu.getX(), equalTo(0xff));
     assertThat(cpu.getY(), equalTo(0x00));