70 lines
1.8 KiB
TypeScript
70 lines
1.8 KiB
TypeScript
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import { MOS6502 } from "../common/cpu/MOS6502";
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import { BasicHeadlessMachine, HasSerialIO, SerialIOInterface } from "../common/devices";
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import { padBytes, newAddressDecoder } from "../common/emu"; // TODO
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const INPUT_HALTED = 31;
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export class Devel6502 extends BasicHeadlessMachine implements HasSerialIO {
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cpuFrequency = 1000000;
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defaultROMSize = 0x8000;
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cpu = new MOS6502();
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ram = new Uint8Array(0x4000);
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rom : Uint8Array;
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serial : SerialIOInterface;
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constructor() {
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super();
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this.connectCPUMemoryBus(this);
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}
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connectSerialIO(serial: SerialIOInterface) {
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this.serial = serial;
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}
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read = newAddressDecoder([
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[0x0000, 0x3fff, 0x3fff, (a) => { return this.ram[a]; }],
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[0x4000, 0x4000, 0xffff, (a) => { return this.serial.byteAvailable() ? 0x80 : 0 }],
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[0x4001, 0x4001, 0xffff, (a) => { return this.serial.recvByte() }],
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[0x4002, 0x4002, 0xffff, (a) => { return this.serial.clearToSend() ? 0x80 : 0 }],
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[0x8000, 0xffff, 0x7fff, (a) => { return this.rom && this.rom[a]; }],
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]);
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write = newAddressDecoder([
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[0x0000, 0x3fff, 0x3fff, (a,v) => { this.ram[a] = v; }],
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[0x4003, 0x4003, 0xffff, (a,v) => { return this.serial.sendByte(v) }],
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[0x400f, 0x400f, 0xffff, (a,v) => { this.inputs[INPUT_HALTED] = 1; }],
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]);
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readConst(a:number) : number {
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return this.read(a);
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}
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advanceFrame(trap) : number {
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var clock = 0;
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while (clock < this.cpuFrequency/60) {
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if (trap && trap()) break;
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clock += this.advanceCPU();
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}
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return clock;
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}
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advanceCPU() {
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if (this.isHalted()) return 1;
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var n = super.advanceCPU();
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if (this.serial) this.serial.advance(n);
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return n;
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}
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reset() {
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this.inputs[INPUT_HALTED] = 0;
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super.reset();
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if (this.serial) this.serial.reset();
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}
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isHalted() { return this.inputs[INPUT_HALTED] != 0; }
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}
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