mirror of
https://github.com/sehugg/8bitworkshop.git
synced 2024-10-31 08:05:41 +00:00
122 lines
3.5 KiB
TypeScript
122 lines
3.5 KiB
TypeScript
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import { MOS6502 } from "../common/cpu/MOS6502";
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import { disassemble6502 } from "../common/cpu/disasm6502";
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import { Bus } from "../common/devices";
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import { hex, rpad } from "../common/util";
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class CPUSimulator implements Bus {
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cpu : MOS6502;
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ram : Uint8Array;
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ok = false;
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linebuf = '';
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constructor() {
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this.cpu = new MOS6502();
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this.ram = new Uint8Array(0x10000);
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this.cpu.connectMemoryBus(this);
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}
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loadROM(rom: Uint8Array) {
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var hdrlen = 0;
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var prgstart = 0x200;
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if (rom[0] == 0x00) hdrlen = 0;
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else if (rom[0] == 0x73 && rom[1] == 0x69) hdrlen = 12;
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else throw Error("Bad header " + rom[0]);
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this.ram.set(rom.slice(hdrlen), prgstart);
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this.ram[0xfff4] = 0x60; // RTS
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this.ram[0xfff5] = 0x60; // RTS
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this.ram[0xfff6] = 0x60; // RTS
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this.ram[0xfff7] = 0x60; // RTS
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this.ram[0xfff8] = 0x60; // RTS
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this.ram[0xfffc] = (prgstart & 0xff);
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this.ram[0xfffd] = ((prgstart >> 8) & 0xff);
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this.cpu.reset();
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this.ok = true;
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}
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read(a: number): number {
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return this.ram[a] & 0xff;
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}
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write(a: number, v: number): void {
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if (a >= 0x200 && a <= 0xbfff) {
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this.warn("Write in code area: " + hex(a,4))
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}
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if (a >= 0x100 && a < (this.cpu.getSP()|0x100)) {
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this.warn("Write outside stack area: " + hex(a,4))
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}
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this.ram[a] = v;
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}
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readConst?(a: number): number {
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return this.ram[a] & 0xff;
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}
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tick() {
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this.cpu.advanceInsn();
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this.log();
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}
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warn(s:string) {
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console.log("###",hex(this.cpu.getPC(),4),s);
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}
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log() {
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var st = this.cpu.saveState();
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var pc = this.cpu.getPC();
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var b0 = this.readConst(pc);
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var b1 = this.readConst(pc+1);
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var b2 = this.readConst(pc+2);
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var line = disassemble6502(pc, b0, b1, b2);
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var stack = "";
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for (var i=0xff; i>st.SP-0; i--) {
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stack += hex(this.readConst(i+0x100),2);
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//if (i==st.SP) stack += " ";
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}
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console.log(
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hex(pc,4),
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rpad(line.line, 30),
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hex(st.A), hex(st.X), hex(st.Y), hex(st.SP),
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st.C?"C":"-", st.N?"N":"-", st.Z?"Z":"-", st.V?"V":"-",
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stack);
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if (pc == 0xfff7) {
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let addr = this.readStackArg(0);
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let s = '';
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for (var i=0; i<this.readStackArg(2); i++) {
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let cc = this.readConst(addr+i);
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s += String.fromCharCode(cc);
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this.linebuf += s;
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if (cc == 10 || cc == 13) {
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console.log("---LINE", this.linebuf);
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this.linebuf = '';
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}
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}
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console.log("---WRITE", s, st.A, hex(addr), this.readStackArg(2));
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}
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else if (pc == 0xfff9) {
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console.log("---EXIT", st.A);
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this.ok = false;
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}
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else if (b0 == 0x00 || line.line == 'KIL') {
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this.ok = false;
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}
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else if (b0 == 0x20 || b0 == 0x60) {
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console.log();
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}
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}
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readStackArg(offset: number) : number {
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var a = (this.cpu.getSP() | 0x100) + offset + 3;
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return this.readConst(a) + this.readConst(a+1) * 256;
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}
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}
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const fs = require('fs');
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const rom = fs.readFileSync(process.argv[2], null);
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console.log(rom);
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var sim = new CPUSimulator();
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sim.loadROM(rom);
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while (sim.ok) {
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sim.tick();
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}
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