Added sound

index.html

@@ -27,6 +27,7 @@
 
 	<script>
 		const emulator = new Revuelto8ts.Chip8Emulator();
+		const emulatorCanvas = document.getElementById('emulator-screen');
 
 		let fullDirRoms = [
 			'./roms/1-chip8-logo.ch8',
@@ -40,23 +41,56 @@
 			'./roms/Maze[David Winter, 199x].ch8',
 		];
 
+		// Set user keys
+		emulator.setUserKey('1'.charCodeAt(0), 1); 	// 1
+		emulator.setUserKey('2'.charCodeAt(0), 2);	// 2
+		emulator.setUserKey('3'.charCodeAt(0), 3);	// 3
+		emulator.setUserKey('4'.charCodeAt(0), 12);	// C
+		
+		emulator.setUserKey('q'.charCodeAt(0), 4);	// 4
+		emulator.setUserKey('w'.charCodeAt(0), 5);	// 5
+		emulator.setUserKey('e'.charCodeAt(0), 6);	// 6
+		emulator.setUserKey('r'.charCodeAt(0), 13);	// D
+
+		emulator.setUserKey('a'.charCodeAt(0), 7);	// 7
+		emulator.setUserKey('s'.charCodeAt(0), 8);	// 8
+		emulator.setUserKey('d'.charCodeAt(0), 9);	// 9
+		emulator.setUserKey('f'.charCodeAt(0), 14);	// E
+
+		emulator.setUserKey('z'.charCodeAt(0), 10);	// A
+		emulator.setUserKey('x'.charCodeAt(0), 0);	// 0
+		emulator.setUserKey('c'.charCodeAt(0), 11);	// B
+		emulator.setUserKey('v'.charCodeAt(0), 15);	// F
+		
+		document.addEventListener("keydown", function(evt) {
+			emulator.keyDownEvent(evt.key.charCodeAt(0));
+		});
+		document.addEventListener("keyup", function(evt) {
+			emulator.keyUpEvent(evt.key.charCodeAt(0));
+		});
+
+		// Set audio
+		var audioContext = new (window.AudioContext || window.webkitAudioContext)();
+		let volume = 0.02; // Volume between [1, 0] // Set it low if you don't want to become deaf
+		emulator.startAudio(audioContext, volume);
+
 		// Load ROM
-		fetch(fullDirRoms[3])
+		fetch(fullDirRoms[6])
 			.then(response => response.arrayBuffer())
 			.then(arrayBufferRom => {
 				let romData = new Uint8Array(arrayBufferRom);
 				emulator.loadRom(romData);
 		});
 		
-		const emulatorCanvas = document.getElementById('emulator-screen');
+		
 
 		setInterval(function() {
 			if(emulator.isRomLoaded()) {
-				//console.log(emulator.getCPUStatus());
+				console.log(emulator.getCPUStatus());
 				emulator.emulateCycle();
 				emulator.drawToCanvas(emulatorCanvas, 8);
 			}
-			}, 5);
+			}, 60);
 	</script>
 </body>
 </html>

src/audio.ts

@@ -0,0 +1,41 @@
+class Chip8Audio {
+	audioBrowserContext: AudioContext | null;
+	oscillator: OscillatorNode | null;
+	gainNode: GainNode | null;
+
+	volume: number;
+
+	constructor() {
+		this.audioBrowserContext = null;
+		this.oscillator = null;
+		this.gainNode = null;
+		this.volume = 0.1;
+	}
+
+	startAudio(audioContext: AudioContext, volume: number) {
+		this.volume = volume;
+		this.audioBrowserContext = audioContext;
+		this.gainNode = this.audioBrowserContext.createGain();
+		this.gainNode.connect(this.audioBrowserContext.destination);
+		this.gainNode.gain.setValueAtTime(this.volume, this.audioBrowserContext.currentTime);
+	}
+
+	startBeep() {
+		if(this.oscillator == null && this.audioBrowserContext && this.gainNode) {
+			this.oscillator = this.audioBrowserContext.createOscillator();
+			this.oscillator.type = 'square';
+			this.oscillator.frequency.setValueAtTime(440, this.audioBrowserContext.currentTime); // 440 Hz (A4 note)
+			this.oscillator.connect(this.gainNode);
+			this.oscillator.start();
+		}
+	}
+
+	stopBeep() {
+		if(this.oscillator) {
+			this.oscillator.stop();
+			this.oscillator = null;
+		}
+	}
+}
+
+export default Chip8Audio;

src/chip8Emulator.ts

@@ -1,17 +1,21 @@
 import CPU from './cpu';
 import Keyboard from './keyboard'
 import RNG from './RNG'
+import Chip8Audio from './audio'
 
 class Chip8Emulator {
 	cpu: CPU;
 	keyboard: Keyboard;
 	rom: Uint8Array;
+	audio: Chip8Audio;
 
 	romLoaded: boolean;
 
 	constructor() {
 		this.keyboard = new Keyboard();
-		this.cpu = new CPU(this.keyboard);
+		this.audio = new Chip8Audio();
+		this.cpu = new CPU(this.keyboard, this.audio);
+		
 
 		this.rom = new Uint8Array();
 		this.romLoaded = false;
@@ -57,6 +61,14 @@ class Chip8Emulator {
 		}
 	}
 
+	setUserKey(userKey: number, key: number) {
+		this.keyboard.setUserKey(userKey, key);
+	}
+
+	startAudio(audioContext: AudioContext, volume: number) {
+		this.audio.startAudio(audioContext, volume);
+	}
+
 	keyDownEvent(key: number) {
 		this.keyboard.userKeyPressedDown(key);
 	}
@@ -64,9 +76,6 @@ class Chip8Emulator {
 	keyUpEvent(key: number) {
 		this.keyboard.userKeyPressedUp(key);
 	}
-
-
-
 }
 
 export default Chip8Emulator;

src/cpu.ts

@@ -1,4 +1,5 @@
 import RNG from './RNG'
+import Chip8Audio from './audio';
 import Keyboard from './keyboard';
 
 const SCREEN_WIDTH = 64;
@@ -24,11 +25,13 @@ class CPU {
 	displayMemory: Uint8Array;
 	
 	keyboard: Keyboard;
+	audio: Chip8Audio;
+
 
 	rng: RNG;
 	
 
-	constructor(keyboard: Keyboard) {
+	constructor(keyboard: Keyboard, audio: Chip8Audio) {
 		this.memory = new Uint8Array(MEMORY_SIZE);
 		this.displayMemory = new Uint8Array(SCREEN_WIDTH*SCREEN_HEIGHT);
 		this.pc = 0x200;
@@ -39,6 +42,7 @@ class CPU {
 		this.soundTimer = 0;
 		this.regs = new Uint8Array(REGISTERS);
 		this.keyboard = keyboard;
+		this.audio = audio;
 		
 		this.rng = new RNG(0);
 
@@ -249,8 +253,14 @@ class CPU {
 				}else if(nib4 == 0x5) {
 					// 8XY5
 					// Vx -= Vy
-					let subs = this.regs[nib2] - this.regs[nib3];
-					this.regs[0xF] = this.regs[nib2] > this.regs[nib3] ? 1 : 0;
+					let subs = 0;
+					if(this.regs[nib2] >= this.regs[nib3]) {
+						subs = this.regs[nib2] - this.regs[nib3];
+					}else{
+						subs = this.regs[nib2] - this.regs[nib3];
+						//subs = 0xFF - subs;
+					}
+					this.regs[0xF] = this.regs[nib2] >= this.regs[nib3] ? 1 : 0;
 					this.regs[nib2] = subs & 0xFF;
 					this.incrementPC();
 				}else if(nib4 == 0x6) {
@@ -258,8 +268,8 @@ class CPU {
 					// Vx >>= 1
 					// Stores the least significant bit of VX prior to the shift in VF
 					// Then. Shift Vx by 1 to the right.
-					this.regs[0xF] = this.regs[nib2] & 1; // Get the least significat bit
-					this.regs[nib2] = this.regs[nib2] >> 1;
+					this.regs[0xF] = this.regs[nib2] & 0x1; // Get the least significat bit
+					this.regs[nib2] = (this.regs[nib2] >> 1) & 0xFF;
 					this.incrementPC();
 				}else if(nib4 == 0x7) {
 					// 8XY7
@@ -273,8 +283,8 @@ class CPU {
 					// Vx <<= 1
 					// Set VF to 1 if the most significant bit of VX.
 					// Then shift to the left Vx
-					this.regs[0xF] = this.regs[nib2] >> 7;
-					this.regs[nib2] = (this.regs[nib2] << 1) & 0xFF;
+					this.regs[0xF] = (this.regs[nib2]) >> 7;
+					this.regs[nib2] = (this.regs[nib2] << 1);
 					this.incrementPC();
 				}
 
@@ -439,8 +449,16 @@ class CPU {
 				break;
 		}
 
-		if(this.delayTimer > 0)this.delayTimer--;
-		if(this.soundTimer > 0)this.soundTimer--; // Should I play a sound???
+		// Timers
+		if(this.delayTimer > 0) {
+			this.delayTimer--;
+		}
+		if(this.soundTimer > 0)  {
+			this.audio.startBeep();
+			this.soundTimer--;
+		}else{
+			this.audio.stopBeep();
+		}
 	}