Add cassette motor relay sound effects to BBC Micro emulator

src/6502.js

@@ -569,7 +569,7 @@ function is1MHzAccess(addr) {
 }
 
 export class Cpu6502 extends Base6502 {
-    constructor(model, dbgr, video_, soundChip_, ddNoise_, music5000_, cmos, config, econet_) {
+    constructor(model, dbgr, video_, soundChip_, ddNoise_, relayNoise_, music5000_, cmos, config, econet_) {
         super(model);
         this.config = fixUpConfig(config);
         this.debugFlags = this.config.debugFlags;
@@ -582,6 +582,7 @@ export class Cpu6502 extends Base6502 {
         this.soundChip = soundChip_;
         this.music5000 = music5000_;
         this.ddNoise = ddNoise_;
+        this.relayNoise = relayNoise_;
         this.memStatOffsetByIFetchBank = 0;
         this.memStatOffset = 0;
         this.memStat = new Uint8Array(512);
@@ -630,7 +631,7 @@ export class Cpu6502 extends Base6502 {
             this.config.getGamepads,
         );
         this.uservia = new via.UserVia(this, this.scheduler, this.model.isMaster, this.config.userPort);
-        this.acia = new Acia(this, this.soundChip.toneGenerator, this.scheduler, this.touchScreen);
+        this.acia = new Acia(this, this.soundChip.toneGenerator, this.scheduler, this.touchScreen, this.relayNoise);
         this.serial = new Serial(this.acia);
         this.adconverter = new Adc(this.sysvia, this.scheduler);
         this.soundChip.setScheduler(this.scheduler);

src/acia.js

@@ -5,10 +5,11 @@
 // http://www.classiccmp.org/dunfield/r/6850.pdf
 
 export class Acia {
-    constructor(cpu, toneGen, scheduler, rs423Handler) {
+    constructor(cpu, toneGen, scheduler, rs423Handler, relayNoise) {
         this.cpu = cpu;
         this.toneGen = toneGen;
         this.rs423Handler = rs423Handler;
+        this.relayNoise = relayNoise;
 
         this.sr = 0x00;
         this.cr = 0x00;
@@ -58,10 +59,16 @@ export class Acia {
     setMotor(on) {
         if (on && !this.motorOn) {
             this.runTape();
+            if (this.relayNoise) {
+                this.relayNoise.motorOn();
+            }
         } else if (!on && this.motorOn) {
             this.toneGen.mute();
             this.runTapeTask.cancel();
             this.setTapeCarrier(false);
+            if (this.relayNoise) {
+                this.relayNoise.motorOff();
+            }
         }
         this.motorOn = on;
     }

src/audio-utils.js

@@ -0,0 +1,56 @@
+"use strict";
+import * as utils from "./utils.js";
+import _ from "underscore";
+
+export async function loadSounds(context, sounds) {
+    const loaded = await Promise.all(
+        _.map(sounds, async (sound) => {
+            // Safari doesn't support the Promise stuff directly, so we create
+            // our own Promise here.
+            const data = await utils.loadData(sound);
+            return await new Promise((resolve) => {
+                context.decodeAudioData(data.buffer, (decodedData) => {
+                    resolve(decodedData);
+                });
+            });
+        }),
+    );
+    const keys = _.keys(sounds);
+    const result = {};
+    for (let i = 0; i < keys.length; ++i) {
+        result[keys[i]] = loaded[i];
+    }
+    return result;
+}
+
+export class BaseAudioNoise {
+    constructor(context, volume = 0.25) {
+        this.context = context;
+        this.sounds = {};
+        this.gain = context.createGain();
+        this.gain.gain.value = volume;
+        this.gain.connect(context.destination);
+        // workaround for older safaris that GC sounds when they're playing...
+        this.playing = [];
+        this.volume = volume;
+    }
+
+    oneShot(sound) {
+        const duration = sound.duration;
+        const context = this.context;
+        if (context.state !== "running") return duration;
+        const source = context.createBufferSource();
+        source.buffer = sound;
+        source.connect(this.gain);
+        source.start();
+        return duration;
+    }
+
+    mute() {
+        this.gain.gain.value = 0;
+    }
+
+    unmute() {
+        this.gain.gain.value = this.volume;
+    }
+}

src/ddnoise.js

@@ -1,23 +1,16 @@
 "use strict";
-import * as utils from "./utils.js";
+import { loadSounds, BaseAudioNoise } from "./audio-utils.js";
 import _ from "underscore";
 
 const IDLE = 0;
 const SPIN_UP = 1;
 const SPINNING = 2;
-const VOLUME = 0.25;
 
-export class DdNoise {
+export class DdNoise extends BaseAudioNoise {
     constructor(context) {
-        this.context = context;
-        this.sounds = {};
+        super(context, 0.25);
         this.state = IDLE;
         this.motor = null;
-        this.gain = context.createGain();
-        this.gain.gain.value = VOLUME;
-        this.gain.connect(context.destination);
-        // workaround for older safaris that GC sounds when they're playing...
-        this.playing = [];
     }
     async initialise() {
         const sounds = await loadSounds(this.context, {
@@ -31,16 +24,6 @@ export class DdNoise {
         });
         this.sounds = sounds;
     }
-    oneShot(sound) {
-        const duration = sound.duration;
-        const context = this.context;
-        if (context.state !== "running") return duration;
-        const source = context.createBufferSource();
-        source.buffer = sound;
-        source.connect(this.gain);
-        source.start();
-        return duration;
-    }
     play(sound, loop) {
         if (this.context.state !== "running") return Promise.reject();
         return new Promise((resolve) => {
@@ -94,33 +77,6 @@ export class DdNoise {
         else if (diff <= 40) return this.oneShot(this.sounds.seek2);
         else return this.oneShot(this.sounds.seek3);
     }
-    mute() {
-        this.gain.gain.value = 0;
-    }
-    unmute() {
-        this.gain.gain.value = VOLUME;
-    }
-}
-
-async function loadSounds(context, sounds) {
-    const loaded = await Promise.all(
-        _.map(sounds, async (sound) => {
-            // Safari doesn't support the Promise stuff directly, so we create
-            // our own Promise here.
-            const data = await utils.loadData(sound);
-            return await new Promise((resolve) => {
-                context.decodeAudioData(data.buffer, (decodedData) => {
-                    resolve(decodedData);
-                });
-            });
-        }),
-    );
-    const keys = _.keys(sounds);
-    const result = {};
-    for (let i = 0; i < keys.length; ++i) {
-        result[keys[i]] = loaded[i];
-    }
-    return result;
 }
 
 export class FakeDdNoise {

src/fake6502.js

@@ -5,6 +5,7 @@ import { FakeVideo } from "./video.js";
 import { FakeSoundChip } from "./soundchip.js";
 import { findModel, TEST_6502, TEST_65C02, TEST_65C12 } from "./models.js";
 import { FakeDdNoise } from "./ddnoise.js";
+import { FakeRelayNoise } from "./relaynoise.js";
 import { Cpu6502 } from "./6502.js";
 import { Cmos } from "./cmos.js";
 import { FakeMusic5000 } from "./music5000.js";
@@ -20,7 +21,16 @@ export function fake6502(model, opts) {
     const video = opts.video || fakeVideo;
     model = model || TEST_6502;
     if (opts.tube) model.tube = findModel("Tube65c02");
-    return new Cpu6502(model, dbgr, video, soundChip, new FakeDdNoise(), new FakeMusic5000(), new Cmos());
+    return new Cpu6502(
+        model,
+        dbgr,
+        video,
+        soundChip,
+        new FakeDdNoise(),
+        new FakeRelayNoise(),
+        new FakeMusic5000(),
+        new Cmos(),
+    );
 }
 
 export function fake65C02() {

src/main.js

@@ -522,6 +522,7 @@ processor = new Cpu6502(
     video,
     audioHandler.soundChip,
     audioHandler.ddNoise,
+    audioHandler.relayNoise,
     model.hasMusic5000 ? audioHandler.music5000 : null,
     cmos,
     emulationConfig,

src/relaynoise.js

@@ -0,0 +1,39 @@
+"use strict";
+import { loadSounds, BaseAudioNoise } from "./audio-utils.js";
+
+export class RelayNoise extends BaseAudioNoise {
+    constructor(context) {
+        super(context, 0.25);
+    }
+
+    async initialise() {
+        const sounds = await loadSounds(this.context, {
+            motorOn: "sounds/tape/motor_on.wav",
+            motorOff: "sounds/tape/motor_off.wav",
+        });
+        this.sounds = sounds;
+    }
+
+    motorOn() {
+        if (this.sounds.motorOn) {
+            this.oneShot(this.sounds.motorOn);
+        }
+    }
+
+    motorOff() {
+        if (this.sounds.motorOff) {
+            this.oneShot(this.sounds.motorOff);
+        }
+    }
+}
+
+export class FakeRelayNoise {
+    constructor() {}
+    initialise() {
+        return Promise.resolve();
+    }
+    motorOn() {}
+    motorOff() {}
+    mute() {}
+    unmute() {}
+}

src/web/audio-handler.js

@@ -1,6 +1,7 @@
 import { SmoothieChart, TimeSeries } from "smoothie";
 import { FakeSoundChip, SoundChip } from "../soundchip.js";
 import { DdNoise, FakeDdNoise } from "../ddnoise.js";
+import { RelayNoise, FakeRelayNoise } from "../relaynoise.js";
 import { Music5000, FakeMusic5000 } from "../music5000.js";
 
 // Using this approach means when jsbeeb is embedded in other projects, vite doesn't have a fit.
@@ -35,6 +36,7 @@ export class AudioHandler {
             this.audioContext.onstatechange = () => this.checkStatus();
             this.soundChip = new SoundChip((buffer, time) => this._onBuffer(buffer, time));
             this.ddNoise = noSeek ? new FakeDdNoise() : new DdNoise(this.audioContext);
+            this.relayNoise = new RelayNoise(this.audioContext);
             this._setup(audioFilterFreq, audioFilterQ).then();
         } else {
             if (this.audioContext && !this.audioContext.audioWorklet) {
@@ -52,6 +54,7 @@ export class AudioHandler {
             }
             this.soundChip = new FakeSoundChip();
             this.ddNoise = new FakeDdNoise();
+            this.relayNoise = new FakeRelayNoise();
         }
 
         this.warningNode.on("mousedown", () => this.tryResume());
@@ -132,15 +135,18 @@ export class AudioHandler {
 
     async initialise() {
         await this.ddNoise.initialise();
+        await this.relayNoise.initialise();
     }
 
     mute() {
         this.soundChip.mute();
         this.ddNoise.mute();
+        this.relayNoise.mute();
     }
 
     unmute() {
         this.soundChip.unmute();
         this.ddNoise.unmute();
+        this.relayNoise.unmute();
     }
 }

tests/unit/test-acia-relay-integration.js

@@ -0,0 +1,66 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { Acia } from "../../src/acia.js";
+
+describe("ACIA relay noise integration", () => {
+    let mockCpu, mockToneGen, mockScheduler, mockRs423Handler, mockRelayNoise;
+    let acia;
+
+    beforeEach(() => {
+        mockCpu = { interrupt: 0 };
+        mockToneGen = { mute: vi.fn(), tone: vi.fn() };
+        mockScheduler = {
+            newTask: vi.fn((_fn) => ({
+                cancel: vi.fn(),
+                ensureScheduled: vi.fn(),
+            })),
+        };
+        mockRs423Handler = {};
+        mockRelayNoise = {
+            motorOn: vi.fn(),
+            motorOff: vi.fn(),
+        };
+
+        acia = new Acia(mockCpu, mockToneGen, mockScheduler, mockRs423Handler, mockRelayNoise);
+    });
+
+    afterEach(() => {
+        vi.restoreAllMocks();
+    });
+
+    describe("setMotor with relay noise", () => {
+        it("should call relay noise motorOn when motor turns on", () => {
+            acia.motorOn = false;
+
+            acia.setMotor(true);
+
+            expect(mockRelayNoise.motorOn).toHaveBeenCalledOnce();
+            expect(acia.motorOn).toBe(true);
+        });
+
+        it("should call relay noise motorOff when motor turns off", () => {
+            acia.motorOn = true;
+
+            acia.setMotor(false);
+
+            expect(mockRelayNoise.motorOff).toHaveBeenCalledOnce();
+            expect(acia.motorOn).toBe(false);
+        });
+
+        it("should not call relay noise methods when motor state doesn't change", () => {
+            acia.motorOn = true;
+
+            acia.setMotor(true);
+
+            expect(mockRelayNoise.motorOn).not.toHaveBeenCalled();
+            expect(mockRelayNoise.motorOff).not.toHaveBeenCalled();
+        });
+
+        it("should handle missing relay noise gracefully", () => {
+            const aciaWithoutRelayNoise = new Acia(mockCpu, mockToneGen, mockScheduler, mockRs423Handler, null);
+            aciaWithoutRelayNoise.motorOn = false;
+
+            expect(() => aciaWithoutRelayNoise.setMotor(true)).not.toThrow();
+            expect(aciaWithoutRelayNoise.motorOn).toBe(true);
+        });
+    });
+});