added simple sound output

src/logic/Computer.ts

@@ -1,5 +1,6 @@
 import Processor from './Processor';
 import Graphics from './Graphics';
+import Sound from './Sound';
 import Memory from './Memory';
 import { Storage, File, Directory, Program } from './Storage';
 import biosUrl from '../assets/roms/bios.prg?url';
@@ -32,6 +33,7 @@ export class Computer {
     status: Status = Status.OFF;
     cpu: Processor;
     gfx: Graphics;
+    snd: Sound;
     mem: Memory;
     stor: Storage;
     domUpdateInstructionsInterval: number = 2_500; // adjust this for fps
@@ -55,6 +57,10 @@ export class Computer {
                 if (!this.gfx) return;
                 this.gfx.checkMemWrite(index);
             },
+            index => {
+                if (!this.snd) return;
+                this.snd.checkMemWrite(index);
+            },
             index => {
                 if (!this.stor) return;
                 this.stor.checkMemWrite(index);
@@ -63,6 +69,8 @@ export class Computer {
 
         this.gfx = new Graphics(monitorWidth, monitorHeight, this.mem);
 
+        this.snd = new Sound(this.mem);
+
         this.cpu = new Processor(this.mem);
 
         this.stor = new Storage(this.mem);

src/logic/Memory.ts

@@ -1,10 +1,17 @@
 export default class Memory {
     int: number[];
     private onChangeGfx: (index: number) => void;
+    private onChangeSnd: (index: number) => void;
     private onChangeStor: (index: number) => void;
 
-    constructor(size: number = 65536, callbackGfx: (index: number) => void, callbackStor: (index: number) => void) {
+    constructor(
+        size: number = 65536,
+        callbackGfx: (index: number) => void,
+        callbackSnd: (index: number) => void,
+        callbackStor: (index: number) => void
+    ) {
         this.onChangeGfx = callbackGfx;
+        this.onChangeSnd = callbackSnd;
         this.onChangeStor = callbackStor;
 
         this.int = [];
@@ -26,6 +33,7 @@ export default class Memory {
         this.int[index] = value;
 
         this.onChangeGfx(index);
+        this.onChangeSnd(index);
         this.onChangeStor(index);
     }
 
@@ -38,6 +46,7 @@ export default class Memory {
         this.int[index] = isNaN(value) ? 0 : value;
 
         this.onChangeGfx(index);
+        this.onChangeSnd(index);
         this.onChangeStor(index);
     }
 
@@ -57,6 +66,7 @@ export default class Memory {
         }
 
         this.onChangeGfx(index);
+        this.onChangeSnd(index);
         this.onChangeStor(index);
     }
 
@@ -65,6 +75,7 @@ export default class Memory {
         if (this.int[index] > 255) this.int[index] = this.int[index] % 256;
 
         this.onChangeGfx(index);
+        this.onChangeSnd(index);
         this.onChangeStor(index);
     }
 
@@ -73,6 +84,7 @@ export default class Memory {
         if (this.int[index] < 0) this.int[index] = 256 + this.int[index]; // this.int is negative
 
         this.onChangeGfx(index);
+        this.onChangeSnd(index);
         this.onChangeStor(index);
     }
 

src/logic/Sound.ts

@@ -0,0 +1,82 @@
+import Memory from './Memory';
+
+const registerWaveformDuration = 0x0224;
+const registerStartStopFrequency = 0x0225; // Word
+
+export default class Sound {
+    private mem: Memory;
+    private duration: number = 0;
+    private frequency: number = 0;
+    private waveform: OscillatorType = 'sine';
+
+    constructor(mem: Memory) {
+        this.mem = mem;
+
+        this.init();
+    }
+
+    init() {
+        this.updateWaveformDuration();
+
+        this.updateStartStopFrequency(0);
+    }
+
+    start() {
+        const ctx = new AudioContext();
+        const osc = ctx.createOscillator();
+        osc.type = this.waveform;
+        osc.frequency.value = this.frequency;
+        osc.connect(ctx.destination);
+        osc.start();
+
+        const classSound = this;
+        // Beep for 500 milliseconds
+        setTimeout(function () {
+            osc.stop();
+            classSound.mem.setInt(registerStartStopFrequency + 1, classSound.mem.int[registerStartStopFrequency + 1] & 0b01111111);
+        }, this.duration); // Duration in ms
+    }
+
+    checkMemWrite(index: number) {
+        if (index === registerWaveformDuration) this.updateWaveformDuration();
+        if (index === registerStartStopFrequency || index === registerStartStopFrequency + 1) this.updateStartStopFrequency(index);
+    }
+
+    updateWaveformDuration() {
+        // registerWaveformDuration
+        // [2 Bits Waveform | 6 Bits Duration *10 in ms]
+        let waveform: OscillatorType;
+        switch ((this.mem.int[registerWaveformDuration] & 0b11000000) >> 6) {
+            case 0:
+                waveform = 'sine';
+                break;
+            case 1:
+                waveform = 'square';
+                break;
+            case 2:
+                waveform = 'sawtooth';
+                break;
+            case 3:
+                waveform = 'triangle';
+                break;
+
+            default:
+                waveform = 'sine';
+                break;
+        }
+
+        this.waveform = waveform;
+
+        this.duration = (this.mem.int[registerWaveformDuration] & 0b00111111) * 10;
+    }
+
+    updateStartStopFrequency(index: number) {
+        // registerStartStopFrequency
+        // [1 Bit Start/Stop | 7 Bits Frequency]
+        this.frequency = ((this.mem.int[registerStartStopFrequency + 1] & 0b01111111) << 8) | this.mem.int[registerStartStopFrequency];
+
+        if ((this.mem.int[registerStartStopFrequency + 1] & 0b10000000) >> 7 === 1) {
+            this.start();
+        }
+    }
+}