demo prog and bugfixes in screen and rtc

src/main/kotlin/razorvine/examplemachine/GUI.kt

@@ -175,7 +175,7 @@ class DebugWindow(val vm: VirtualMachine) : JFrame("debugger"), ActionListener {
         buttonPanel.border = BorderFactory.createTitledBorder("Control")
 
         val resetBt = JButton("Reset").also { it.actionCommand = "reset" }
-        val cycleBt = JButton("Cycle").also { it.actionCommand = "cycle" }
+        val cycleBt = JButton("Step").also { it.actionCommand = "step" }
         listOf(resetBt, cycleBt, pauseBt).forEach {
             it.addActionListener(this)
             buttonPanel.add(it)
@@ -192,8 +192,8 @@ class DebugWindow(val vm: VirtualMachine) : JFrame("debugger"), ActionListener {
                 vm.bus.reset()
                 updateCpu(vm.cpu)
             }
-            e.actionCommand == "cycle" -> {
-                vm.bus.clock()
+            e.actionCommand == "step" -> {
+                vm.stepInstruction()
                 updateCpu(vm.cpu)
             }
             e.actionCommand == "pause" -> {

src/main/kotlin/razorvine/examplemachine/systemMain.kt

@@ -29,6 +29,7 @@ class VirtualMachine(title: String) {
     init {
         ram[Cpu6502.RESET_vector] = 0x00
         ram[Cpu6502.RESET_vector + 1] = 0x10
+        ram.loadPrg(javaClass.getResource("/vmdemo.prg").toURI())
 
         bus += rtc
         bus += timer
@@ -47,38 +48,26 @@ class VirtualMachine(title: String) {
 
     var paused = false
 
-    fun clock() {
-        if(!paused) {
-            bus.clock()
-            debugWindow.updateCpu(cpu)
+    fun stepInstruction() {
+        while (cpu.instrCycles > 0) bus.clock()
+        bus.clock()
+        while (cpu.instrCycles > 0) bus.clock()
+    }
+
+    fun start() {
+        val timer = java.util.Timer("clock", true)
+        timer.scheduleAtFixedRate(1, 1) {
+            if(!paused) {
+                repeat(10) {
+                    stepInstruction()
+                }
+                debugWindow.updateCpu(cpu)
+            }
         }
     }
 }
 
 fun main(args: Array<String>) {
     val machine = VirtualMachine("KSim65 demo virtual machine - using ksim65 v${Version.version}")
-    val v = 0xd000
-
-    machine.bus[v + 0x08] = 20
-    machine.bus[v + 0x09] = 2
-    val text = ">> Hello this is an example text! 1234567890 <<\n" +
-            "next line 1\n" +
-            "next line 2\n" +
-            "next line 3\rnext line 4\rnext line 5\n" +
-            "a mistakk\be\n\n\n\n\n\n\n\n\n\n"
-    text.forEach {
-        machine.bus[v + 0x0a] = it.toShort()
-    }
-
-    repeat(20) {
-        Thread.sleep(100)
-        "time: ${LocalDateTime.now()}\n".forEach { c ->
-            machine.bus[v + 0x0a] = c.toShort()
-        }
-    }
-
-    val timer = java.util.Timer("clock", true)
-    timer.scheduleAtFixedRate(1, 1) {
-        machine.clock()
-    }
+    machine.start()
 }

src/main/kotlin/razorvine/ksim65/Bus.kt

@@ -49,8 +49,13 @@ class Bus {
      */
     fun read(address: Address): UByte {
         memComponents.forEach {
-            if (address >= it.startAddress && address <= it.endAddress)
-                return it[address]
+            if (address >= it.startAddress && address <= it.endAddress) {
+                val data = it[address]
+                require(data in 0..255) {
+                    "data must be a byte 0..255"
+                }
+                return data
+            }
         }
         return 0xff
     }
@@ -60,7 +65,9 @@ class Bus {
      * Any memory mapped component that listens to the address, will receive the data.
      */
     fun write(address: Address, data: UByte) {
-        require(data in 0..255) { "data must be a byte 0..255" }
+        require(data in 0..255) {
+            "data must be a byte 0..255"
+        }
         memComponents.forEach {
             if (address >= it.startAddress && address <= it.endAddress)
                 it[address] = data

src/main/kotlin/razorvine/ksim65/components/Display.kt

@@ -1,5 +1,6 @@
 package razorvine.ksim65.components
 
+import razorvine.examplemachine.ScreenDefs
 import razorvine.ksim65.IHostInterface
 import kotlin.math.min
 
@@ -67,11 +68,17 @@ class Display(
 
     override operator fun get(address: Address): UByte {
         return when(address-startAddress) {
+            0x00 -> charposX.toShort()
+            0x01 -> charposY.toShort()
             0x02 -> {
                 if(charposY in 0 until charHeight && charposX in 0 until charWidth) {
                     charMatrix[charposY][charposX]
                 } else 0xff
             }
+            0x03 -> (pixelX and 0xff).toShort()
+            0x04 -> (pixelX ushr 8).toShort()
+            0x05 -> (pixelY and 0xff).toShort()
+            0x06 -> (pixelY ushr 8).toShort()
             0x07 -> if(host.getPixel(pixelX, pixelY)) 1 else 0
             0x08 -> cursorX.toShort()
             0x09 -> cursorY.toShort()
@@ -99,8 +106,10 @@ class Display(
             0x05 -> pixelY = (pixelY and 0xff00) or data.toInt()
             0x06 -> pixelY = (pixelY and 0x00ff) or (data.toInt() shl 8)
             0x07 -> {
-                if(data==0.toShort()) host.clearPixel(pixelX, pixelY)
-                else host.setPixel(pixelX, pixelY)
+                if(pixelX in 0 until ScreenDefs.SCREEN_WIDTH && pixelY in 0 until ScreenDefs.SCREEN_HEIGHT) {
+                    if (data == 0.toShort()) host.clearPixel(pixelX, pixelY)
+                    else host.setPixel(pixelX, pixelY)
+                }
             }
             0x08 -> cursorX = min(data.toInt() and 65535, charWidth-1)
             0x09 -> cursorY = min(data.toInt() and 65535, charHeight-1)

src/main/kotlin/razorvine/ksim65/components/Ram.kt

@@ -1,7 +1,9 @@
 package razorvine.ksim65.components
 
 import java.io.File
+import java.net.URI
 import java.net.URL
+import java.nio.file.Paths
 
 /**
  * A RAM chip with read/write memory.
@@ -31,7 +33,14 @@ class Ram(startAddress: Address, endAddress: Address) : MemoryComponent(startAdd
      * Load a c64-style prg program. This file type has the load address as the first two bytes.
      */
     fun loadPrg(filename: String) {
-        val bytes = File(filename).readBytes()
+        loadPrg(Paths.get(filename).toUri())
+    }
+
+    /**
+     * Load a c64-style prg program. This file type has the load address as the first two bytes.
+     */
+    fun loadPrg(file: URI) {
+        val bytes = File(file).readBytes()
         val loadAddress = (bytes[0].toInt() or (bytes[1].toInt() shl 8)) and 65535
         val baseAddress = loadAddress - startAddress
         bytes.drop(2).forEachIndexed { index, byte ->

src/main/kotlin/razorvine/ksim65/components/RealTimeClock.kt

@@ -50,11 +50,11 @@ class RealTimeClock(startAddress: Address, endAddress: Address) : MemMappedCompo
             0x05 -> LocalTime.now().minute.toShort()
             0x06 -> LocalTime.now().second.toShort()
             0x07 -> {
-                val ms = LocalTime.now().nano / 1000
+                val ms = LocalTime.now().nano / 1000000
                 (ms and 255).toShort()
             }
             0x08 -> {
-                val ms = LocalTime.now().nano / 1000
+                val ms = LocalTime.now().nano / 1000000
                 (ms ushr 8).toShort()
             }
             else -> 0xff

src/main/resources/vmdemo.asm

@@ -0,0 +1,114 @@
+
+	.cpu "6502"
+
+	DISPLAY = $d000
+	RTC	= $d100
+	TIMER	= $d200
+	MOUSE   = $d300
+	KEYBOARD = $d400
+	SCREEN_WIDTH=640
+
+	* = $1000
+
+start
+	sei
+	ldx  #$ff
+	txs
+	cli
+
+; ------- fill the screen
+	ldx  #0
+	ldy  #0
+fillscreen
+	stx  DISPLAY+0
+	sty  DISPLAY+1
+	lda  character
+	sta  DISPLAY+2		; plot the char on the screen
+	inc  character
+	inx
+	cpx  #80
+	bne  fillscreen
+	ldx  #0
+	iny
+	cpy  #30
+	bne  fillscreen
+
+; ------- clear the screen
+	lda  #$0c		; form feed (clear screen)
+	sta  DISPLAY+$0a
+
+; ------- draw pixel line
+pixelline
+	ldx  pix_x
+	stx  DISPLAY+3
+	ldx  pix_x+1
+	stx  DISPLAY+4
+	ldx  pix_y
+	stx  DISPLAY+5
+	ldx  pix_y+1
+	stx  DISPLAY+6
+	lda  #1
+	sta  DISPLAY+7		; plot
+	lda  pix_x
+	clc
+	adc  #2
+	sta  pix_x
+	bcc  +
+	inc  pix_x+1
++	inc  pix_y
+	bne  +
+	inc  pix_y+1
++	lda  pix_x+1
+	cmp  #>SCREEN_WIDTH
+	bcc  pixelline
+	bne  stop1
+	lda  pix_x
+	cmp  #<SCREEN_WIDTH
+	bcc  pixelline
+	bcs  stop1
+pix_x	.word 0
+pix_y	.word 0
+
+stop1
+
+;--------- draw with mouse
+mousedraw
+	ldx  MOUSE+0
+	ldy  MOUSE+2
+	stx  DISPLAY+3
+	sty  DISPLAY+5
+	ldx  MOUSE+1
+	ldy  MOUSE+3
+	stx  DISPLAY+4
+	sty  DISPLAY+6
+	lda  #1
+	sta  DISPLAY+7		; plot pixel
+	jmp  mousedraw
+
+
+;--------- RTC display  TODO
+	ldy  #0
+	lda  #0
+	sta  DISPLAY+0
+	sta  DISPLAY+1
+rtcloop
+	ldx  #0
+readrtc
+	lda  RTC,x
+	sta  DISPLAY+2
+	inc  DISPLAY+0
+	inx
+	cpx  #9
+	bne  readrtc
+	lda  #0
+	sta  DISPLAY+0
+	iny
+	sty  DISPLAY+1
+	cpy  #20
+	bne  rtcloop
+
+
+done	jmp  done
+
+
+character .byte 0