mirror of https://github.com/irmen/ksim65.git
416 lines
18 KiB
Kotlin
416 lines
18 KiB
Kotlin
package razorvine.c64emu
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import razorvine.ksim65.Cpu6502
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import razorvine.ksim65.components.Address
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import razorvine.ksim65.components.MemMappedComponent
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import razorvine.ksim65.components.UByte
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import java.awt.event.KeyEvent
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/**
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* Minimal simulation of the MOS 6526 CIA chip.
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* Depending on what CIA it is (1 or 2), some registers do different things on the C64.
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* This implementation provides a working keyboard matrix, joystick in port#2 (cia 1),
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* time of day clock, and the essentials of the timer A and B.
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*/
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class Cia(val number: Int, startAddress: Address, endAddress: Address, val cpu: Cpu6502) : MemMappedComponent(startAddress, endAddress) {
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private var ramBuffer = Array<UByte>(endAddress-startAddress+1) { 0 }
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private var regPRA = 0xff
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// joystick in port 2 configuration (only works on cia#1)
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private var joy2up = false
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private var joy2down = false
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private var joy2left = false
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private var joy2right = false
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private var joy2fire = false
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class TimeOfDay {
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private var updatedAt = 0L
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private var startedAt = 0L
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private var userStartTime = 0.0
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private var running = false
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var hours = 0
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var minutes = 0
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var seconds = 0
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var tenths = 0
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private var latchedTime = 0L
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private var latched = false
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fun start() {
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if (!running) {
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updatedAt = System.currentTimeMillis()
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startedAt = updatedAt
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userStartTime = hours*3600+minutes*60+seconds+tenths/10.0
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running = true
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}
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latch(false)
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}
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fun stop() {
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running = false
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}
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fun latch(latched: Boolean) {
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this.latched = latched
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update()
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}
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fun update() {
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if (!running || latched) return
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latchedTime = System.currentTimeMillis()
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if (updatedAt != latchedTime) {
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updatedAt = latchedTime
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var elapsedSeconds = (latchedTime.toDouble()-startedAt)/1000.0+userStartTime
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if(elapsedSeconds>60*3600)
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elapsedSeconds=0.0 // TOD counds max 60 hours
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hours = (elapsedSeconds/3600).toInt()
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elapsedSeconds -= hours*3600
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minutes = (elapsedSeconds/60).toInt()
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elapsedSeconds -= minutes*60
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seconds = (elapsedSeconds).toInt()
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elapsedSeconds -= seconds
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tenths = (elapsedSeconds*10).toInt()
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}
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}
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}
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private var totalCycles = 0
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private var tod = TimeOfDay()
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private var timerAset = 0
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private var timerBset = 0
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private var timerAactual = 0
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private var timerBactual = 0
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private var timerAinterruptEnabled = false
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private var timerBinterruptEnabled = false
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private data class HostKeyPress(val code: Int, val rightSide: Boolean = false, val numpad: Boolean = false)
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private val hostKeyPresses = mutableSetOf<HostKeyPress>()
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init {
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require(endAddress-startAddress+1 == 256) { "cia requires exactly 256 memory bytes (16*16 mirrored)" }
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}
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override fun clock() {
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totalCycles++
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if (totalCycles%20000 == 0) {
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// TOD resolution is 0.1 second, no need to update it in every bus cycle
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tod.update()
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}
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if (ramBuffer[0x0e].toInt() and 1 != 0) {
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// timer A is enabled, assume system cycles counting for now
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timerAactual--
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if (timerAactual == 0 && timerAinterruptEnabled) {
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if (number == 1) cpu.irqAsserted = true
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else if (number == 2) cpu.nmiAsserted = true
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}
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if (timerAactual < 0) timerAactual = if (ramBuffer[0x0e].toInt() and 0b00001000 != 0) 0 else timerAset
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}
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if (ramBuffer[0x0f].toInt() and 1 != 0) {
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// timer B is enabled
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val regCRB = ramBuffer[0x0f].toInt()
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if (regCRB and 0b01000000 != 0) {
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// timer B counts timer A underruns
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if (timerAactual == 0) timerBactual--
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} else {
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// timer B counts just the system cycles
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timerBactual--
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}
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if (timerBactual == 0 && timerBinterruptEnabled) {
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if (number == 1) cpu.irqAsserted = true
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else if (number == 2) cpu.nmiAsserted = true
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}
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if (timerBactual < 0) timerBactual = if (regCRB and 0b00001000 != 0) 0 else timerBset
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}
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}
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override fun reset() {
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hostKeyPresses.clear()
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tod.stop()
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ramBuffer.fill(0)
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timerAactual = 0
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timerAset = 0
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timerBactual = 0
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timerBset = 0
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joy2up = false
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joy2down = false
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joy2left = false
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joy2right = false
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joy2fire = false
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}
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override operator fun get(offset: Int): UByte {
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fun scanColumn(vararg keys: HostKeyPress): UByte {
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var bits = 0b10000000
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var presses = 0
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for (key in keys) {
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if (key in hostKeyPresses) presses = presses or bits
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bits = bits ushr 1
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}
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return (presses.inv() and 255).toShort()
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}
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val register = offset and 15
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if(number==1) {
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// first CIA has keyboard matrix
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if(register==0x00) {
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// reading $dc00 is joystick in port #2
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return (0b01100000
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or (if(joy2up) 0 else 0b00000001)
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or (if(joy2down) 0 else 0b00000010)
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or (if(joy2left) 0 else 0b00000100)
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or (if(joy2right) 0 else 0b00001000)
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or (if(joy2fire) 0 else 0b00010000)).toShort()
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} else if(register==0x01) {
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// register 1 on CIA#1 is the keyboard data port (and joystick #1...)
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// if bit is cleared in PRA, contains keys pressed in that column of the matrix
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// NOTE: we do not emulate a joystick in port #1 as this conflicts with the keyboard.
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// just use the joystick in port #2 for now...
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return when (regPRA) {
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0b00000000 -> {
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// check if any keys are pressed at all (by checking all columns at once)
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if (hostKeyPresses.isEmpty()) 0xff.toShort() else 0x00.toShort()
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}
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0b11111110 -> {
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// read column 0
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scanColumn(HostKeyPress(KeyEvent.VK_DOWN), HostKeyPress(KeyEvent.VK_F5), HostKeyPress(KeyEvent.VK_F3),
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HostKeyPress(KeyEvent.VK_F1), HostKeyPress(KeyEvent.VK_F7), HostKeyPress(KeyEvent.VK_RIGHT),
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HostKeyPress(KeyEvent.VK_ENTER), HostKeyPress(KeyEvent.VK_BACK_SPACE))
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}
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0b11111101 -> {
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// read column 1
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scanColumn(HostKeyPress(KeyEvent.VK_SHIFT), // left shift
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HostKeyPress(KeyEvent.VK_E), HostKeyPress(KeyEvent.VK_S), HostKeyPress(KeyEvent.VK_Z),
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HostKeyPress(KeyEvent.VK_4), HostKeyPress(KeyEvent.VK_A), HostKeyPress(KeyEvent.VK_W),
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HostKeyPress(KeyEvent.VK_3))
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}
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0b11111011 -> {
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// read column 2
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scanColumn(HostKeyPress(KeyEvent.VK_X), HostKeyPress(KeyEvent.VK_T), HostKeyPress(KeyEvent.VK_F),
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HostKeyPress(KeyEvent.VK_C), HostKeyPress(KeyEvent.VK_6), HostKeyPress(KeyEvent.VK_D),
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HostKeyPress(KeyEvent.VK_R), HostKeyPress(KeyEvent.VK_5))
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}
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0b11110111 -> {
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// read column 3
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scanColumn(HostKeyPress(KeyEvent.VK_V), HostKeyPress(KeyEvent.VK_U), HostKeyPress(KeyEvent.VK_H),
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HostKeyPress(KeyEvent.VK_B), HostKeyPress(KeyEvent.VK_8), HostKeyPress(KeyEvent.VK_G),
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HostKeyPress(KeyEvent.VK_Y), HostKeyPress(KeyEvent.VK_7))
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}
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0b11101111 -> {
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// read column 4
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scanColumn(HostKeyPress(KeyEvent.VK_N), HostKeyPress(KeyEvent.VK_O), HostKeyPress(KeyEvent.VK_K),
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HostKeyPress(KeyEvent.VK_M), HostKeyPress(KeyEvent.VK_0), HostKeyPress(KeyEvent.VK_J),
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HostKeyPress(KeyEvent.VK_I), HostKeyPress(KeyEvent.VK_9))
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}
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0b11011111 -> {
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// read column 5
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scanColumn(HostKeyPress(KeyEvent.VK_COMMA), HostKeyPress(KeyEvent.VK_AT), HostKeyPress(KeyEvent.VK_COLON),
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HostKeyPress(KeyEvent.VK_PERIOD), HostKeyPress(KeyEvent.VK_MINUS), HostKeyPress(KeyEvent.VK_L),
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HostKeyPress(KeyEvent.VK_P), HostKeyPress(KeyEvent.VK_PLUS))
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}
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0b10111111 -> {
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// read column 6
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scanColumn(HostKeyPress(KeyEvent.VK_SLASH), HostKeyPress(KeyEvent.VK_CIRCUMFLEX), HostKeyPress(KeyEvent.VK_EQUALS),
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HostKeyPress(KeyEvent.VK_SHIFT, rightSide = true), // right shift
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HostKeyPress(KeyEvent.VK_HOME), HostKeyPress(KeyEvent.VK_SEMICOLON), HostKeyPress(KeyEvent.VK_ASTERISK),
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HostKeyPress(KeyEvent.VK_DEAD_TILDE) // pound sign
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)
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}
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0b01111111 -> {
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// read column 7
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scanColumn(HostKeyPress(KeyEvent.VK_ESCAPE), HostKeyPress(KeyEvent.VK_Q), HostKeyPress(KeyEvent.VK_ALT),
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HostKeyPress(KeyEvent.VK_SPACE), HostKeyPress(KeyEvent.VK_2), HostKeyPress(KeyEvent.VK_CONTROL),
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HostKeyPress(KeyEvent.VK_BACK_QUOTE), HostKeyPress(KeyEvent.VK_1))
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}
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else -> {
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// invalid column selection
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0xff
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}
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}
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}
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}
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return when (register) {
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0x04 -> (timerAactual and 0xff).toShort()
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0x05 -> (timerAactual ushr 8).toShort()
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0x06 -> (timerBactual and 0xff).toShort()
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0x07 -> (timerBactual ushr 8).toShort()
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0x08 -> {
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tod.start()
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(tod.tenths and 0x0f).toShort()
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}
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0x09 -> toBCD(tod.seconds)
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0x0a -> toBCD(tod.minutes)
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0x0b -> {
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tod.latch(true)
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toBCD(tod.hours)
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}
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else -> ramBuffer[register]
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}
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}
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override operator fun set(offset: Int, data: UByte) {
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val register = offset and 15
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if (number == 1 && register == 0x00) {
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// PRA data port A (select keyboard matrix column)
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regPRA = data.toInt()
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}
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if (register != 0x0d) ramBuffer[register] = data
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when (register) {
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0x04 -> {
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if (ramBuffer[0x0e].toInt() and 0b10000000 == 0) {
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timerAset = (timerAset and 0xff00) or data.toInt()
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timerAactual = timerAset
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}
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}
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0x05 -> {
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if (ramBuffer[0x0e].toInt() and 0b10000000 == 0) {
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timerAset = (timerAset and 0x00ff) or (data.toInt() shl 8)
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timerAactual = timerAset
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}
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}
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0x06 -> {
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if (ramBuffer[0x0f].toInt() and 0b10000000 == 0) {
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timerBset = (timerBset and 0xff00) or data.toInt()
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timerBactual = timerBset
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}
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}
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0x07 -> {
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if (ramBuffer[0x0f].toInt() and 0b10000000 == 0) {
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timerBset = (timerBset and 0x00ff) or (data.toInt() shl 8)
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timerBactual = timerBset
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}
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}
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0x08 -> tod.tenths = data.toInt() and 0x0f
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0x09 -> tod.seconds = fromBCD(data)
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0x0a -> tod.minutes = fromBCD(data)
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0x0b -> {
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tod.stop()
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tod.hours = fromBCD(data)
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}
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0x0d -> {
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if (data.toInt() and 0b10000000 != 0) {
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// set ICR bits
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val newICR = ramBuffer[0x0d].toInt() or (data.toInt() and 0b01111111)
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timerAinterruptEnabled = newICR and 1 != 0
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timerBinterruptEnabled = newICR and 2 != 0
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ramBuffer[0x0d] = newICR.toShort()
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} else {
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// clear ICR bits
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val newICR = ramBuffer[0x0d].toInt() and (data.toInt() and 0b01111111).inv()
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timerAinterruptEnabled = newICR and 1 != 0
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timerBinterruptEnabled = newICR and 2 != 0
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ramBuffer[0x0d] = newICR.toShort()
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}
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}
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}
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}
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private fun toBCD(data: Int): UByte {
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val tens = data/10
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val ones = data-tens*10
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return ((tens shl 4) or ones).toShort()
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}
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private fun fromBCD(bcd: UByte): Int {
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val ibcd = bcd.toInt()
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val tens = ibcd ushr 4
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val ones = ibcd and 0x0f
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return tens*10+ones
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}
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fun hostKeyPressed(event: KeyEvent) {
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val rightSide = event.keyLocation == KeyEvent.KEY_LOCATION_RIGHT
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val numpad = event.keyLocation == KeyEvent.KEY_LOCATION_NUMPAD
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val shift = HostKeyPress(KeyEvent.VK_SHIFT, rightSide = true, numpad = false)
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fun register(eventId: Int, vararg keys: HostKeyPress) {
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if (eventId == KeyEvent.KEY_PRESSED) keys.forEach { hostKeyPresses.add(it) }
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else keys.forEach { hostKeyPresses.remove(it) }
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}
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fun unregister(keyCode: Int) {
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hostKeyPresses.removeAll { it.code == keyCode }
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}
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// to avoid some 'stuck' keys, if we receive a shift/control/alt RELEASE, we wipe the keyboard buffer
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// (this can happen because we're changing the key code for some pressed keys below,
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// and a released key doesn't always match the pressed key code anymore then)
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if (event.id == KeyEvent.KEY_RELEASED && event.keyCode in listOf(KeyEvent.VK_SHIFT, KeyEvent.VK_CONTROL, KeyEvent.VK_ALT,
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KeyEvent.VK_ALT_GRAPH)
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) hostKeyPresses.clear()
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// try to remap the keys a bit so a modern PC keyboard maps better to the keys of the C64
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when (event.keyChar) {
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'@' -> {
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unregister(KeyEvent.VK_SHIFT)
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register(event.id, HostKeyPress(KeyEvent.VK_AT))
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}
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'^' -> {
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unregister(KeyEvent.VK_SHIFT)
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register(event.id, HostKeyPress(KeyEvent.VK_CIRCUMFLEX))
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}
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'*' -> {
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unregister(KeyEvent.VK_SHIFT)
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register(event.id, HostKeyPress(KeyEvent.VK_ASTERISK))
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}
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'+' -> {
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unregister(KeyEvent.VK_SHIFT)
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register(event.id, HostKeyPress(KeyEvent.VK_PLUS))
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}
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':' -> {
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unregister(KeyEvent.VK_SHIFT)
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register(event.id, HostKeyPress(KeyEvent.VK_COLON))
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}
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'~' -> {
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unregister(KeyEvent.VK_SHIFT)
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register(event.id, HostKeyPress(KeyEvent.VK_DEAD_TILDE))
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}
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'&' -> register(event.id, shift, HostKeyPress(KeyEvent.VK_6))
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'(' -> register(event.id, shift, HostKeyPress(KeyEvent.VK_8))
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')' -> register(event.id, shift, HostKeyPress(KeyEvent.VK_9))
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'[' -> register(event.id, shift, HostKeyPress(KeyEvent.VK_COLON))
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']' -> register(event.id, shift, HostKeyPress(KeyEvent.VK_SEMICOLON))
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'"' -> register(event.id, HostKeyPress(KeyEvent.VK_2))
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'\'' -> register(event.id, shift, HostKeyPress(KeyEvent.VK_7))
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else -> // F2 = shift+F1
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// F4 = shift+F3
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// F6 = shift+F5
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// F8 = shift+F7
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// insert = shift+backspace(del)
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// up = shift+down
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// left = shift+right
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// just map the key as usual
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// both alts map to the 'commodore key' (same left alt)
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// both controls and the tab key map to the 'single left control'
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when (event.keyCode) {
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KeyEvent.VK_CONTROL, KeyEvent.VK_TAB -> register(event.id, HostKeyPress(KeyEvent.VK_CONTROL))
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KeyEvent.VK_ALT, KeyEvent.VK_ALT_GRAPH -> register(event.id, HostKeyPress(KeyEvent.VK_ALT))
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KeyEvent.VK_F2 -> register(event.id, shift, HostKeyPress(KeyEvent.VK_F1))
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KeyEvent.VK_F4 -> register(event.id, shift, HostKeyPress(KeyEvent.VK_F3))
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KeyEvent.VK_F6 -> register(event.id, shift, HostKeyPress(KeyEvent.VK_F5))
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KeyEvent.VK_F8 -> register(event.id, shift, HostKeyPress(KeyEvent.VK_F7))
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KeyEvent.VK_INSERT -> register(event.id, shift, HostKeyPress(KeyEvent.VK_BACK_SPACE))
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KeyEvent.VK_UP -> register(event.id, shift, HostKeyPress(KeyEvent.VK_DOWN))
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KeyEvent.VK_LEFT -> register(event.id, shift, HostKeyPress(KeyEvent.VK_RIGHT))
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else -> register(event.id, HostKeyPress(event.keyCode, rightSide, numpad))
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}
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}
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}
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fun setJoystick2(up: Boolean, down: Boolean, left: Boolean, right: Boolean, fire: Boolean) {
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if(number!=1)
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throw NotImplementedError("joystick port 2 is connected to cia#1")
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joy2up = up
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joy2down = down
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joy2left = left
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joy2right = right
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joy2fire = fire
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}
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}
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