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timer A+B binding

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This commit is contained in:
Irmen de Jong 2019-10-05 23:34:43 +02:00
parent 3f78c13b80
commit f152443475
2 changed files with 16 additions and 6 deletions
src/main/kotlin/razorvine
c64emu
Cia.kt
examplemachines
GUI.kt

18
src/main/kotlin/razorvine/c64emu/Cia.kt

@ -9,7 +9,7 @@ import java.awt.event.KeyEvent
* Minimal simulation of the MOS 6526 CIA chip.
* Depending on what CIA it is (1 or 2), some registers do different things on the C64.
* This implementation provides a working keyboard matrix, TOD clock, and the essentials of the timer A and B.
* TODO: timer IRQ triggering, more timer control bits. Validate that the timerA/B timing is cycle correct.
* TODO: timerA IRQ, timerB NMI triggering
*/
class Cia(val number: Int, startAddress: Address, endAddress: Address) : MemMappedComponent(startAddress, endAddress) {
private var ramBuffer = Array<UByte>(endAddress - startAddress + 1) { 0 }
@ -88,14 +88,24 @@ class Cia(val number: Int, startAddress: Address, endAddress: Address) : MemMapp
}
if(ramBuffer[0x0e].toInt() and 1 != 0) {
// timer A is enabled, assume system cycles counting for now
timerAactual--
if(timerAactual<0)
timerAactual = if(ramBuffer[0x0e].toInt() and 0b1000 != 0) 0 else timerAset
timerAactual = if(ramBuffer[0x0e].toInt() and 0b00001000 != 0) 0 else timerAset
}
if(ramBuffer[0x0f].toInt() and 1 != 0) {
timerBactual--
// timer B is enabled
val crb = ramBuffer[0x0f].toInt()
if(crb and 0b01000000 != 0) {
// timer B counts timer A underruns
if(timerAactual==0)
timerBactual--
} else {
// timer B counts just the system cycles
timerBactual--
}
if(timerBactual<0)
timerBactual = if(ramBuffer[0x0f].toInt() and 0b1000 != 0) 0 else timerBset
timerBactual = if(crb and 0b00001000 != 0) 0 else timerBset
}
}

4
src/main/kotlin/razorvine/examplemachines/GUI.kt

@ -227,7 +227,7 @@ class DebugWindow(private val vm: IVirtualMachine) : JFrame("Debugger - ksim65 v
val buttonPanel = JPanel(FlowLayout())
buttonPanel.border = BorderFactory.createTitledBorder("Control")
val loadBt = JButton("Load program").also { it.actionCommand = "load" }
val loadBt = JButton("Inject program").also { it.actionCommand = "inject" }
val resetBt = JButton("Reset").also { it.actionCommand = "reset" }
val stepBt = JButton("Step").also { it.actionCommand = "step" }
val irqBt = JButton("IRQ").also { it.actionCommand = "irq" }
@ -264,7 +264,7 @@ class DebugWindow(private val vm: IVirtualMachine) : JFrame("Debugger - ksim65 v
override fun actionPerformed(e: ActionEvent) {
when(e.actionCommand) {
"load" -> {
"inject" -> {
val chooser = JFileChooser()
chooser.dialogTitle = "Choose binary program or .prg to load"
chooser.currentDirectory = File(".")