Holy-Unblocker/public/assets/js/gb.js

function loadboot(p) {
    var boot = [
        0x31, 0xFE, 0xFF, 0xAF, 0x21, 0xFF, 0x9F, 0x32, 0xCB, 0x7C, 0x20, 0xFB, 0x21, 0x26, 0xFF, 0x0E,
        0x11, 0x3E, 0x80, 0x32, 0xE2, 0x0C, 0x3E, 0xF3, 0xE2, 0x32, 0x3E, 0x77, 0x77, 0x3E, 0xFC, 0xE0,
        0x47, 0x11, 0x04, 0x01, 0x21, 0x10, 0x80, 0x1A, 0xCD, 0x95, 0x00, 0xCD, 0x96, 0x00, 0x13, 0x7B,
        0xFE, 0x34, 0x20, 0xF3, 0x11, 0xD8, 0x00, 0x06, 0x08, 0x1A, 0x13, 0x22, 0x23, 0x05, 0x20, 0xF9,
        0x3E, 0x19, 0xEA, 0x10, 0x99, 0x21, 0x2F, 0x99, 0x0E, 0x0C, 0x3D, 0x28, 0x08, 0x32, 0x0D, 0x20,
        0xF9, 0x2E, 0x0F, 0x18, 0xF3, 0x67, 0x3E, 0x64, 0x57, 0xE0, 0x42, 0x3E, 0x91, 0xE0, 0x40, 0x04,
        0x1E, 0x02, 0x0E, 0x0C, 0xF0, 0x44, 0xFE, 0x90, 0x20, 0xFA, 0x0D, 0x20, 0xF7, 0x1D, 0x20, 0xF2,
        0x0E, 0x13, 0x24, 0x7C, 0x1E, 0x83, 0xFE, 0x62, 0x28, 0x06, 0x1E, 0xC1, 0xFE, 0x64, 0x20, 0x06,
        0x7B, 0xE2, 0x0C, 0x3E, 0x87, 0xE2, 0xF0, 0x42, 0x90, 0xE0, 0x42, 0x15, 0x20, 0xD2, 0x05, 0x20,
        0x4F, 0x16, 0x20, 0x18, 0xCB, 0x4F, 0x06, 0x04, 0xC5, 0xCB, 0x11, 0x17, 0xC1, 0xCB, 0x11, 0x17,
        0x05, 0x20, 0xF5, 0x22, 0x23, 0x22, 0x23, 0xC9, 0xCE, 0xED, 0x66, 0x66, 0xCC, 0x0D, 0x00, 0x0B,
        0x03, 0x73, 0x00, 0x83, 0x00, 0x0C, 0x00, 0x0D, 0x00, 0x08, 0x11, 0x1F, 0x88, 0x89, 0x00, 0x0E,
        0xDC, 0xCC, 0x6E, 0xE6, 0xDD, 0xDD, 0xD9, 0x99, 0xBB, 0xBB, 0x67, 0x63, 0x6E, 0x0E, 0xEC, 0xCC,
        0xDD, 0xDC, 0x99, 0x9F, 0xBB, 0xB9, 0x33, 0x3E, 0x3C, 0x42, 0xB9, 0xA5, 0xB9, 0xA5, 0x42, 0x3C,
        0x21, 0x04, 0x01, 0x11, 0xA8, 0x00, 0x1A, 0x13, 0xBE, 0x00, 0x00, 0x23, 0x7D, 0xFE, 0x34, 0x20,
        0xF5, 0x06, 0x19, 0x78, 0x86, 0x23, 0x05, 0x20, 0xFB, 0x86, 0x00, 0x00, 0x3E, 0x01, 0xE0, 0x50
    ];

    for (var i in boot) {
        p.memory[i] = boot[i];
    }
    p.r.pc = 0;
    p.usingBootRom = true;
}

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    // CPU class
    var CPU = function(gameboy) {
        this.gameboy = gameboy;

        this.r = { A: 0, F: 0, B: 0, C: 0, D: 0, E: 0, H: 0, L: 0, pc: 0, sp: 0 };
        this.IME = true;
        this.clock = { c: 0, serial: 0 };
        this.isHalted = false;
        this.isPaused = false;
        this.usingBootRom = false;

        this.createDevices();
    };

    CPU.INTERRUPTS = {
        VBLANK: 0,
        LCDC: 1,
        TIMER: 2,
        SERIAL: 3,
        HILO: 4
    };
    CPU.interruptRoutines = {
        0: function(p) { GameboyJS.cpuOps.RSTn(p, 0x40); },
        1: function(p) { GameboyJS.cpuOps.RSTn(p, 0x48); },
        2: function(p) { GameboyJS.cpuOps.RSTn(p, 0x50); },
        3: function(p) { GameboyJS.cpuOps.RSTn(p, 0x58); },
        4: function(p) { GameboyJS.cpuOps.RSTn(p, 0x60); }
    };

    CPU.prototype.createDevices = function() {
        this.memory = new GameboyJS.Memory(this);
        this.timer = new GameboyJS.Timer(this, this.memory);
        this.apu = new GameboyJS.APU(this.memory);

        this.SERIAL_INTERNAL_INSTR = 512; // instr to wait per bit if internal clock
        this.enableSerial = 0;
        this.serialHandler = GameboyJS.ConsoleSerial;
    };

    CPU.prototype.reset = function() {
        this.memory.reset();

        this.r.sp = 0xFFFE;
    };

    CPU.prototype.loadRom = function(data) {
        this.memory.setRomData(data);
    };

    CPU.prototype.getRamSize = function() {
        var size = 0;
        switch (this.memory.rb(0x149)) {
            case 1:
                size = 2048;
                break;
            case 2:
                size = 2048 * 4;
                break;
            case 3:
                size = 2048 * 16;
                break;
        }

        return size;
    };

    CPU.prototype.getGameName = function() {
        var name = '';
        for (var i = 0x134; i < 0x143; i++) {
            var char = this.memory.rb(i) || 32;
            name += String.fromCharCode(char);
        }

        return name;
    };

    // Start the execution of the emulator
    CPU.prototype.run = function() {
        if (this.usingBootRom) {
            this.r.pc = 0x0000;
        } else {
            this.r.pc = 0x0100;
        }
        this.frame();
    };

    CPU.prototype.stop = function() {
        clearTimeout(this.nextFrameTimer);
    };

    // Fetch-and-execute loop
    // Will execute instructions for the duration of a frame
    //
    // The screen unit will notify the vblank period which
    // is considered the end of a frame
    //
    // The function is called on a regular basis with a timeout
    CPU.prototype.frame = function() {
        if (!this.isPaused) {
            this.nextFrameTimer = setTimeout(this.frame.bind(this), 1000 / GameboyJS.Screen.physics.FREQUENCY);
        }

        try {
            var vblank = false;
            while (!vblank) {
                var oldInstrCount = this.clock.c;
                if (!this.isHalted) {
                    var opcode = this.fetchOpcode();
                    GameboyJS.opcodeMap[opcode](this);
                    this.r.F &= 0xF0; // tmp fix

                    if (this.enableSerial) {
                        var instr = this.clock.c - oldInstrCount;
                        this.clock.serial += instr;
                        if (this.clock.serial >= 8 * this.SERIAL_INTERNAL_INSTR) {
                            this.endSerialTransfer();
                        }
                    }
                } else {
                    this.clock.c += 4;
                }

                var elapsed = this.clock.c - oldInstrCount;
                vblank = this.gpu.update(elapsed);
                this.timer.update(elapsed);
                this.input.update();
                this.apu.update(elapsed);
                this.checkInterrupt();
            }
            this.clock.c = 0;
        } catch (e) {
            this.gameboy.handleException(e);
        }
    };

    CPU.prototype.fetchOpcode = function() {
        var opcode = this.memory.rb(this.r.pc++);
        if (opcode === undefined) { console.log(opcode + ' at ' + (this.r.pc - 1).toString(16));
            this.stop(); return; }
        if (!GameboyJS.opcodeMap[opcode]) {
            console.error('Unknown opcode ' + opcode.toString(16) + ' at address ' + (this.r.pc - 1).toString(16) + ', stopping execution...');
            this.stop();
            return null;
        }

        return opcode;
    };

    // read register
    CPU.prototype.rr = function(register) {
        return this.r[register];
    };

    // write register
    CPU.prototype.wr = function(register, value) {
        this.r[register] = value;
    };

    CPU.prototype.halt = function() {
        this.isHalted = true;
    };
    CPU.prototype.unhalt = function() {
        this.isHalted = false;
    };
    CPU.prototype.pause = function() {
        this.isPaused = true;
    };
    CPU.prototype.unpause = function() {
        if (this.isPaused) {
            this.isPaused = false;
            this.frame();
        }
    };

    // Look for interrupt flags
    CPU.prototype.checkInterrupt = function() {
        if (!this.IME) {
            return;
        }
        for (var i = 0; i < 5; i++) {
            var IFval = this.memory.rb(0xFF0F);
            if (GameboyJS.Util.readBit(IFval, i) && this.isInterruptEnable(i)) {
                IFval &= (0xFF - (1 << i));
                this.memory.wb(0xFF0F, IFval);
                this.disableInterrupts();
                this.clock.c += 4; // 20 clocks to serve interrupt, with 16 for RSTn
                CPU.interruptRoutines[i](this);
                break;
            }
        }
    };

    // Set an interrupt flag
    CPU.prototype.requestInterrupt = function(type) {
        var IFval = this.memory.rb(0xFF0F);
        IFval |= (1 << type)
        this.memory.wb(0xFF0F, IFval);
        this.unhalt();
    };

    CPU.prototype.isInterruptEnable = function(type) {
        return GameboyJS.Util.readBit(this.memory.rb(0xFFFF), type) != 0;
    };

    CPU.prototype.enableInterrupts = function() {
        this.IME = true;
    };
    CPU.prototype.disableInterrupts = function() {
        this.IME = false;
    };

    CPU.prototype.enableSerialTransfer = function() {
        this.enableSerial = 1;
        this.clock.serial = 0;
    };

    CPU.prototype.endSerialTransfer = function() {
        this.enableSerial = 0;
        var data = this.memory.rb(0xFF01);
        this.memory.wb(0xFF02, 0);
        this.serialHandler.out(data);
        this.memory.wb(0xFF01, this.serialHandler.in());
    };

    CPU.prototype.resetDivTimer = function() {
        this.timer.resetDiv();
    };
    GameboyJS.CPU = CPU;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    var Debug = {};
    // Output a range of 16 memory addresses
    Debug.view_memory = function(addr, gameboy) {
        var memory = gameboy.cpu.memory;
        addr = addr & 0xFFF0;
        var pad = '00';
        var str = addr.toString(16) + ':';
        for (var i = addr; i < addr + 0x10; i++) {
            if ((i & 0x1) == 0) {
                str += ' ';
            }
            var val = memory[i] || 0;

            val = val.toString(16);
            str += pad.substring(val.length) + val;
        }

        return str;
    };

    Debug.view_tile = function(gameboy, index, dataStart) {
        var memory = gameboy.cpu.memory;
        var screen = gameboy.screen;
        var LCDC = screen.deviceram(screen.LCDC);
        if (typeof dataStart === 'undefined') {
            dataStart = 0x8000;
            if (!GameboyJS.Util.readBit(LCDC, 4)) {
                dataStart = 0x8800;
                index = GameboyJS.cpuOps._getSignedValue(index) + 128;
            }
        }

        var tileData = screen.readTileData(index, dataStart);

        var pixelData = new Array(8 * 8)
        for (var line = 0; line < 8; line++) {
            var b1 = tileData.shift();
            var b2 = tileData.shift();

            for (var pixel = 0; pixel < 8; pixel++) {
                var mask = (1 << (7 - pixel));
                var colorValue = ((b1 & mask) >> (7 - pixel)) + ((b2 & mask) >> (7 - pixel)) * 2;
                pixelData[line * 8 + pixel] = colorValue;
            }
        }

        var i = 0;
        while (pixelData.length) {
            console.log(i++ + ' ' + pixelData.splice(0, 8).join(''));
        }
    };

    Debug.list_visible_sprites = function(gameboy) {
        var memory = gameboy.cpu.memory;
        var indexes = new Array();
        for (var i = 0xFE00; i < 0xFE9F; i += 4) {
            var x = memory.oamram(i + 1);
            var y = memory.oamram(i);
            var tileIndex = memory.oamram(i + 2);
            if (x == 0 || x >= 168) {
                continue;
            }
            indexes.push({ oamIndex: i, x: x, y: y, tileIndex: tileIndex });
        }

        return indexes;
    };
    GameboyJS.Debug = Debug;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";
    var Screen;
    var GPU = function(screen, cpu) {
        this.cpu = cpu;
        this.screen = screen;

        this.LCDC = 0xFF40;
        this.STAT = 0xFF41;
        this.SCY = 0xFF42;
        this.SCX = 0xFF43;
        this.LY = 0xFF44;
        this.LYC = 0xFF45;
        this.BGP = 0xFF47;
        this.OBP0 = 0xFF48;
        this.OBP1 = 0xFF49;
        this.WY = 0xFF4A;
        this.WX = 0xFF4B;

        this.vram = cpu.memory.vram.bind(cpu.memory);

        this.OAM_START = 0xFE00;
        this.OAM_END = 0xFE9F;
        this.deviceram = cpu.memory.deviceram.bind(cpu.memory);
        this.oamram = cpu.memory.oamram.bind(cpu.memory);
        this.VBLANK_TIME = 70224;
        this.clock = 0;
        this.mode = 2;
        this.line = 0;

        Screen = GameboyJS.Screen;
        this.buffer = new Array(Screen.physics.WIDTH * Screen.physics.HEIGHT);
        this.tileBuffer = new Array(8);
        this.bgTileCache = {};
    };

    GPU.tilemap = {
        HEIGHT: 32,
        WIDTH: 32,
        START_0: 0x9800,
        START_1: 0x9C00,
        LENGTH: 0x0400 // 1024 bytes = 32*32
    };

    GPU.prototype.update = function(clockElapsed) {
        this.clock += clockElapsed;
        var vblank = false;

        switch (this.mode) {
            case 0: // HBLANK
                if (this.clock >= 204) {
                    this.clock -= 204;
                    this.line++;
                    this.updateLY();
                    if (this.line == 144) {
                        this.setMode(1);
                        vblank = true;
                        this.cpu.requestInterrupt(GameboyJS.CPU.INTERRUPTS.VBLANK);
                        this.drawFrame();
                    } else {
                        this.setMode(2);
                    }
                }
                break;
            case 1: // VBLANK
                if (this.clock >= 456) {
                    this.clock -= 456;
                    this.line++;
                    if (this.line > 153) {
                        this.line = 0;
                        this.setMode(2);
                    }
                    this.updateLY();
                }

                break;
            case 2: // SCANLINE OAM
                if (this.clock >= 80) {
                    this.clock -= 80;
                    this.setMode(3);
                }
                break;
            case 3: // SCANLINE VRAM
                if (this.clock >= 172) {
                    this.clock -= 172;
                    this.drawScanLine(this.line);
                    this.setMode(0);
                }
                break;
        }

        return vblank;
    };

    GPU.prototype.updateLY = function() {
        this.deviceram(this.LY, this.line);
        var STAT = this.deviceram(this.STAT);
        if (this.deviceram(this.LY) == this.deviceram(this.LYC)) {
            this.deviceram(this.STAT, STAT  |  (1 << 2));
            if (STAT & (1 << 6)) {
                this.cpu.requestInterrupt(GameboyJS.CPU.INTERRUPTS.LCDC);
            }
        } else {
            this.deviceram(this.STAT, STAT  &  (0xFF - (1 << 2)));
        }
    };

    GPU.prototype.setMode = function(mode) {
        this.mode = mode;
        var newSTAT = this.deviceram(this.STAT);
        newSTAT &= 0xFC;
        newSTAT |= mode;
        this.deviceram(this.STAT, newSTAT);

        if (mode < 3) {
            if (newSTAT & (1 << (3 + mode))) {
                this.cpu.requestInterrupt(GameboyJS.CPU.INTERRUPTS.LCDC);
            }
        }
    };

    // Push one scanline into the main buffer
    GPU.prototype.drawScanLine = function(line) {
        var LCDC = this.deviceram(this.LCDC);
        var enable = GameboyJS.Util.readBit(LCDC, 7);
        if (enable) {
            var lineBuffer = new Array(Screen.physics.WIDTH);
            this.drawBackground(LCDC, line, lineBuffer);
            this.drawSprites(LCDC, line, lineBuffer);
            // TODO draw a line for the window here too
        }
    };

    GPU.prototype.drawFrame = function() {
        var LCDC = this.deviceram(this.LCDC);
        var enable = GameboyJS.Util.readBit(LCDC, 7);
        if (enable) {
            //this.drawSprites(LCDC);
            this.drawWindow(LCDC);
        }
        this.bgTileCache = {};
        this.screen.render(this.buffer);
    };

    GPU.prototype.drawBackground = function(LCDC, line, lineBuffer) {
        if (!GameboyJS.Util.readBit(LCDC, 0)) {
            return;
        }

        var mapStart = GameboyJS.Util.readBit(LCDC, 3) ? GPU.tilemap.START_1 : GPU.tilemap.START_0;

        var dataStart, signedIndex = false;
        if (GameboyJS.Util.readBit(LCDC, 4)) {
            dataStart = 0x8000;
        } else {
            dataStart = 0x8800;
            signedIndex = true;
        }

        var bgx = this.deviceram(this.SCX);
        var bgy = this.deviceram(this.SCY);
        var tileLine = ((line + bgy) & 7);

        // browse BG tilemap for the line to render
        var tileRow = ((((bgy + line) / 8) |  0) & 0x1F);
        var firstTile = ((bgx / 8) | 0) + 32 * tileRow;
        var lastTile = firstTile + Screen.physics.WIDTH / 8 + 1;
        if ((lastTile & 0x1F) < (firstTile & 0x1F)) {
            lastTile -= 32;
        }
        var x = (firstTile & 0x1F) * 8 - bgx; // x position of the first tile's leftmost pixel
        for (var i = firstTile; i != lastTile; i++, (i & 0x1F) == 0 ? i -= 32 : null) {
            var tileIndex = this.vram(i + mapStart);

            if (signedIndex) {
                tileIndex = GameboyJS.Util.getSignedValue(tileIndex) + 128;
            }

            // try to retrieve the tile data from the cache, or use readTileData() to read from ram
            // TODO find a better cache system now that the BG is rendered line by line
            var tileData = this.bgTileCache[tileIndex] || (this.bgTileCache[tileIndex] = this.readTileData(tileIndex, dataStart));

            this.drawTileLine(tileData, tileLine);
            this.copyBGTileLine(lineBuffer, this.tileBuffer, x);
            x += 8;
        }

        this.copyLineToBuffer(lineBuffer, line);
    };

    // Copy a tile line from a tileBuffer to a line buffer, at a given x position
    GPU.prototype.copyBGTileLine = function(lineBuffer, tileBuffer, x) {
        // copy tile line to buffer
        for (var k = 0; k < 8; k++, x++) {
            if (x < 0 || x >= Screen.physics.WIDTH) continue;
            lineBuffer[x] = tileBuffer[k];
        }
    };

    // Copy a scanline into the main buffer
    GPU.prototype.copyLineToBuffer = function(lineBuffer, line) {
        var bgPalette = GPU.getPalette(this.deviceram(this.BGP));

        for (var x = 0; x < Screen.physics.WIDTH; x++) {
            var color = lineBuffer[x];
            this.drawPixel(x, line, bgPalette[color]);
        }
    };

    // Write a line of a tile (8 pixels) into a buffer array
    GPU.prototype.drawTileLine = function(tileData, line, xflip, yflip) {
        xflip = xflip | 0;
        yflip = yflip | 0;
        var l = yflip ? 7 - line : line;
        var byteIndex = l * 2;
        var b1 = tileData[byteIndex++];
        var b2 = tileData[byteIndex++];

        var offset = 8;
        for (var pixel = 0; pixel < 8; pixel++) {
            offset--;
            var mask = (1 << offset);
            var colorValue = ((b1 & mask) >> offset) + ((b2 & mask) >> offset) * 2;
            var p = xflip ? offset : pixel;
            this.tileBuffer[p] = colorValue;
        }
    };

    GPU.prototype.drawSprites = function(LCDC, line, lineBuffer) {
        if (!GameboyJS.Util.readBit(LCDC, 1)) {
            return;
        }
        var spriteHeight = GameboyJS.Util.readBit(LCDC, 2) ? 16 : 8;

        var sprites = new Array();
        for (var i = this.OAM_START; i < this.OAM_END && sprites.length < 10; i += 4) {
            var y = this.oamram(i);
            var x = this.oamram(i + 1);
            var index = this.oamram(i + 2);
            var flags = this.oamram(i + 3);

            if (y - 16 > line || y - 16 < line - spriteHeight) {
                continue;
            }
            sprites.push({ x: x, y: y, index: index, flags: flags })
        }

        if (sprites.length == 0) return;

        // cache object to store read tiles from this frame
        var cacheTile = {};
        var spriteLineBuffer = new Array(Screen.physics.WIDTH);

        for (var i = 0; i < sprites.length; i++) {
            var sprite = sprites[i];
            var tileLine = line - sprite.y + 16;
            var paletteNumber = GameboyJS.Util.readBit(flags, 4);
            var xflip = GameboyJS.Util.readBit(sprite.flags, 5);
            var yflip = GameboyJS.Util.readBit(sprite.flags, 6);
            var tileData = cacheTile[sprite.index] || (cacheTile[sprite.index] = this.readTileData(sprite.index, 0x8000, spriteHeight * 2));
            this.drawTileLine(tileData, tileLine, xflip, yflip);
            this.copySpriteTileLine(spriteLineBuffer, this.tileBuffer, sprite.x - 8, paletteNumber);
        }

        this.copySpriteLineToBuffer(spriteLineBuffer, line);
    };

    // Copy a tile line from a tileBuffer to a line buffer, at a given x position
    GPU.prototype.copySpriteTileLine = function(lineBuffer, tileBuffer, x, palette) {
        // copy tile line to buffer
        for (var k = 0; k < 8; k++, x++) {
            if (x < 0 || x >= Screen.physics.WIDTH || tileBuffer[k] == 0) continue;
            lineBuffer[x] = { color: tileBuffer[k], palette: palette };
        }
    };

    // Copy a sprite scanline into the main buffer
    GPU.prototype.copySpriteLineToBuffer = function(spriteLineBuffer, line) {
        var spritePalettes = {};
        spritePalettes[0] = GPU.getPalette(this.deviceram(this.OBP0));
        spritePalettes[1] = GPU.getPalette(this.deviceram(this.OBP1));

        for (var x = 0; x < Screen.physics.WIDTH; x++) {
            if (!spriteLineBuffer[x]) continue;
            var color = spriteLineBuffer[x].color;
            if (color === 0) continue;
            var paletteNumber = spriteLineBuffer[x].palette;
            this.drawPixel(x, line, spritePalettes[paletteNumber][color]);
        }
    };

    GPU.prototype.drawTile = function(tileData, x, y, buffer, bufferWidth, xflip, yflip, spriteMode) {
        xflip = xflip | 0;
        yflip = yflip | 0;
        spriteMode = spriteMode | 0;
        var byteIndex = 0;
        for (var line = 0; line < 8; line++) {
            var l = yflip ? 7 - line : line;
            var b1 = tileData[byteIndex++];
            var b2 = tileData[byteIndex++];

            for (var pixel = 0; pixel < 8; pixel++) {
                var mask = (1 << (7 - pixel));
                var colorValue = ((b1 & mask) >> (7 - pixel)) + ((b2 & mask) >> (7 - pixel)) * 2;
                if (spriteMode && colorValue == 0) continue;
                var p = xflip ? 7 - pixel : pixel;
                var bufferIndex = (x + p) + (y + l) * bufferWidth;
                buffer[bufferIndex] = colorValue;
            }
        }
    };

    // get an array of tile bytes data (16 entries for 8*8px)
    GPU.prototype.readTileData = function(tileIndex, dataStart, tileSize) {
        tileSize = tileSize || 0x10; // 16 bytes / tile by default (8*8 px)
        var tileData = new Array();

        var tileAddressStart = dataStart + (tileIndex * 0x10);
        for (var i = tileAddressStart; i < tileAddressStart + tileSize; i++) {
            tileData.push(this.vram(i));
        }

        return tileData;
    };

    GPU.prototype.drawWindow = function(LCDC) {
        if (!GameboyJS.Util.readBit(LCDC, 5)) {
            return;
        }

        var buffer = new Array(256 * 256);
        var mapStart = GameboyJS.Util.readBit(LCDC, 6) ? GPU.tilemap.START_1 : GPU.tilemap.START_0;

        var dataStart, signedIndex = false;
        if (GameboyJS.Util.readBit(LCDC, 4)) {
            dataStart = 0x8000;
        } else {
            dataStart = 0x8800;
            signedIndex = true;
        }

        // browse Window tilemap
        for (var i = 0; i < GPU.tilemap.LENGTH; i++) {
            var tileIndex = this.vram(i + mapStart);

            if (signedIndex) {
                tileIndex = GameboyJS.Util.getSignedValue(tileIndex) + 128;
            }

            var tileData = this.readTileData(tileIndex, dataStart);
            var x = i % GPU.tilemap.WIDTH;
            var y = (i / GPU.tilemap.WIDTH) | 0;
            this.drawTile(tileData, x * 8, y * 8, buffer, 256);
        }

        var wx = this.deviceram(this.WX) - 7;
        var wy = this.deviceram(this.WY);
        for (var x = Math.max(0, -wx); x < Math.min(Screen.physics.WIDTH, Screen.physics.WIDTH - wx); x++) {
            for (var y = Math.max(0, -wy); y < Math.min(Screen.physics.HEIGHT, Screen.physics.HEIGHT - wy); y++) {
                var color = buffer[(x & 255) + (y & 255) * 256];
                this.drawPixel(x + wx, y + wy, color);
            }
        }
    };

    GPU.prototype.drawPixel = function(x, y, color) {
        this.buffer[y * 160 + x] = color;
    };

    GPU.prototype.getPixel = function(x, y) {
        return this.buffer[y * 160 + x];
    };

    // Get the palette mapping from a given palette byte as stored in memory
    // A palette will map a tile color to a final palette color index
    // used with Screen.colors to get a shade of grey
    GPU.getPalette = function(paletteByte) {
        var palette = [];
        for (var i = 0; i < 8; i += 2) {
            var shade = (paletteByte & (3 << i)) >> i;
            palette.push(shade);
        }
        return palette;
    };

    GameboyJS.GPU = GPU;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    // Screen device
    var Screen = function(canvas, pixelSize) {
        this.context = canvas.getContext('2d');
        this.canvas = canvas;
        this.pixelSize = pixelSize || 1;
        this.initImageData();
    };

    Screen.colors = [
        0xFF,
        0xAA,
        0x55,
        0x00
    ];

    Screen.physics = {
        WIDTH: 160,
        HEIGHT: 144,
        FREQUENCY: 60
    };

    Screen.prototype.setPixelSize = function(pixelSize) {
        this.pixelSize = pixelSize;
        this.initImageData();
    };

    Screen.prototype.initImageData = function() {
        this.canvas.width = Screen.physics.WIDTH * this.pixelSize;
        this.canvas.height = Screen.physics.HEIGHT * this.pixelSize;
        this.imageData = this.context.createImageData(this.canvas.width, this.canvas.height);
    };

    Screen.prototype.clearScreen = function() {
        this.context.fillStyle = '#FFF';
        this.context.fillRect(0, 0, Screen.physics.WIDTH * this.pixelSize, Screen.physics.HEIGHT * this.pixelSize);
    };

    Screen.prototype.fillImageData = function(buffer) {
        for (var y = 0; y < Screen.physics.HEIGHT; y++) {
            for (var py = 0; py < this.pixelSize; py++) {
                var _y = y * this.pixelSize + py;
                for (var x = 0; x < Screen.physics.WIDTH; x++) {
                    for (var px = 0; px < this.pixelSize; px++) {
                        var offset = _y * this.canvas.width + (x * this.pixelSize + px);
                        var v = Screen.colors[buffer[y * Screen.physics.WIDTH + x]];
                        this.imageData.data[offset * 4] = v;
                        this.imageData.data[offset * 4 + 1] = v;
                        this.imageData.data[offset * 4 + 2] = v;
                        this.imageData.data[offset * 4 + 3] = 255;
                    }
                }
            }
        }
    };

    Screen.prototype.render = function(buffer) {
        this.fillImageData(buffer);
        this.context.putImageData(this.imageData, 0, 0);
    };

    GameboyJS.Screen = Screen;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    // This exception should be thrown whenever a critical feature that
    // has not been implemented is requested
    function UnimplementedException(message, fatal) {
        this.message = message;
        this.name = UnimplementedException;
        if (fatal === undefined) {
            fatal = true;
        }
        this.fatal = fatal;
    }
    GameboyJS.UnimplementedException = UnimplementedException;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    // Object for mapping the cartridge RAM
    var ExtRam = function() {
        this.extRam = null;
        this.ramSize = 0;
        this.ramBank = 0;
    };

    ExtRam.prototype.loadRam = function(game, size) {
        this.gameName = game;

        this.ramSize = size;
        this.ramBanksize = this.ramSize >= 0x2000 ? 8192 : 2048;

        var key = this.getStorageKey();
        var data = localStorage.getItem(key);
        if (data == null) {
            this.extRam = Array.apply(null, new Array(this.ramSize)).map(function() { return 0; });
        } else {
            this.extRam = JSON.parse(data);
            if (this.extRam.length != size) {
                console.error('Found RAM data but not matching expected size.');
            }
        }
    };

    ExtRam.prototype.setRamBank = function(bank) {
        this.ramBank = bank;
    };

    ExtRam.prototype.manageWrite = function(offset, value) {
        this.extRam[this.ramBank * 8192 + offset] = value;
    };

    ExtRam.prototype.manageRead = function(offset) {
        return this.extRam[this.ramBank * 8192 + offset];
    };

    ExtRam.prototype.getStorageKey = function() {
        return this.gameName + '_EXTRAM';;
    };
    // Actually save the RAM in the physical storage (localStorage)
    ExtRam.prototype.saveRamData = function() {
        localStorage.setItem(this.getStorageKey(), JSON.stringify(this.extRam));
    };
    GameboyJS.ExtRam = ExtRam;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    // This is the default buttons mapping for the Gamepad
    // It's optimized for the XBOX pad
    //
    // Any other mapping can be provided as a constructor argument of the Gamepad object
    // An alternative mapping should be an object with keys being the indexes
    // of the gamepad buttons and values the normalized gameboy button names
    var xboxMapping = {
        0: 'UP',
        1: 'DOWN',
        2: 'LEFT',
        3: 'RIGHT',
        4: 'START',
        5: 'SELECT',
        11: 'A',
        12: 'B'
    };

    // Gamepad listener
    // Communication layer between the Gamepad API and the Input class
    // Any physical controller can be used but the mapping should be provided
    // in order to get an optimal layout of the buttons (see above)
    var Gamepad = function(mapping) {
        this.gamepad = null;
        this.state = { A: 0, B: 0, START: 0, SELECT: 0, LEFT: 0, RIGHT: 0, UP: 0, DOWN: 0 };
        this.pullInterval = null;
        this.buttonMapping = mapping || xboxMapping;
    };

    // Initialize the keyboard listeners and set up the callbacks
    // for button press / release
    Gamepad.prototype.init = function(onPress, onRelease) {
        this.onPress = onPress;
        this.onRelease = onRelease;

        var self = this;
        window.addEventListener('gamepadconnected', function(e) {
            self.gamepad = e.gamepad;
            self.activatePull();
        });
        window.addEventListener('gamepaddisconnected', function(e) {
            self.gamepad = null;
            self.deactivatePull();
        });
    };

    Gamepad.prototype.activatePull = function() {
        this.deactivatePull();
        this.pullInterval = setInterval(this.pullState.bind(this), 100);
    };

    Gamepad.prototype.deactivatePull = function() {
        clearInterval(this.pullInterval);
    };

    // Check the state of the current gamepad in order to detect any press/release action
    Gamepad.prototype.pullState = function() {
        for (var index in this.buttonMapping) {
            var button = this.buttonMapping[index];
            var oldState = this.state[button];
            this.state[button] = this.gamepad.buttons[index].pressed;

            if (this.state[button] == 1 && oldState == 0) {
                this.managePress(button);
            } else if (this.state[button] == 0 && oldState == 1) {
                this.manageRelease(button);
            }
        }
    };

    Gamepad.prototype.managePress = function(key) {
        this.onPress(key);
    };

    Gamepad.prototype.manageRelease = function(key) {
        this.onRelease(key);
    };

    GameboyJS.Gamepad = Gamepad;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    // The Input management system
    //
    // The pressKey() and releaseKey() functions should be called by a device class
    // like GameboyJS.Keyboard after a physical button trigger event
    //
    // They rely on the name of the original buttons as parameters (see Input.keys)
    var Input = function(cpu, pad) {
        this.cpu = cpu;
        this.memory = cpu.memory;
        this.P1 = 0xFF00;
        this.state = 0;

        pad.init(this.pressKey.bind(this), this.releaseKey.bind(this));
    };

    Input.keys = {
        START: 0x80,
        SELECT: 0x40,
        B: 0x20,
        A: 0x10,
        DOWN: 0x08,
        UP: 0x04,
        LEFT: 0x02,
        RIGHT: 0x01
    };

    Input.prototype.pressKey = function(key) {
        this.state |= Input.keys[key];

        this.cpu.requestInterrupt(GameboyJS.CPU.INTERRUPTS.HILO);
    };

    Input.prototype.releaseKey = function(key) {
        var mask = 0xFF - Input.keys[key];
        this.state &= mask;
    };

    Input.prototype.update = function() {
        var value = this.memory.rb(this.P1);
        value = ((~value) & 0x30); // invert the value so 1 means 'active'
        if (value & 0x10) { // direction keys listened
            value |= (this.state & 0x0F);
        } else if (value & 0x20) { // action keys listened
            value |= ((this.state & 0xF0) >> 4);
        } else if ((value & 0x30) == 0) { // no keys listened
            value &= 0xF0;
        }

        value = ((~value) & 0x3F); // invert back
        this.memory[this.P1] = value;
    };
    GameboyJS.Input = Input;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    // Keyboard listener
    // Does the mapping between the keyboard and the Input class
    var Keyboard = function() {};

    // Initialize the keyboard listeners and set up the callbacks
    // for button press / release
    Keyboard.prototype.init = function(onPress, onRelease) {
        this.onPress = onPress;
        this.onRelease = onRelease;

        var self = this;
        document.addEventListener('keydown', function(e) {
            self.managePress(e.keyCode);
        });
        document.addEventListener('keyup', function(e) {
            self.manageRelease(e.keyCode);
        });
    }

    Keyboard.prototype.managePress = function(keycode) {
        var key = this.translateKey(keycode);
        if (key) {
            this.onPress(key);
        }
    };

    Keyboard.prototype.manageRelease = function(keycode) {
        var key = this.translateKey(keycode);
        if (key) {
            this.onRelease(key);
        }
    };

    // Transform a keyboard keycode into a key of the Input.keys object
    Keyboard.prototype.translateKey = function(keycode) {
        var key = null;
        switch (keycode) {
            case 71: // G
                key = 'A';
                break;
            case 66: // B
                key = 'B';
                break;
            case 72: // H
                key = 'START';
                break;
            case 78: // N
                key = 'SELECT';
                break;
            case 37: // left
                key = 'LEFT';
                break;
            case 38: // up
                key = 'UP';
                break;
            case 39: // right
                key = 'RIGHT';
                break;
            case 40: // down
                key = 'DOWN';
                break;
        }

        return key;
    };
    GameboyJS.Keyboard = Keyboard;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    // List of CPU operations
    // Most operations have been factorized here to limit code redundancy
    //
    // How to read operations:
    // Uppercase letters qualify the kind of operation (LD = LOAD, INC = INCREMENT, etc.)
    // Lowercase letters are used to hint parameters :
    // r = register, n = 1 memory byte, sp = sp register,
    // a = suffix for memory address, i = bit index
    // Example : LDrrar = LOAD operation with two-registers memory address
    // as first parameter and one register value as second
    //
    // Underscore-prefixed functions are here to delegate the logic between similar operations,
    // they should not be called from outside
    //
    // It's up to each operation to update the CPU clock
    var ops = {
        LDrrnn: function(p, r1, r2) { p.wr(r2, p.memory.rb(p.r.pc));
            p.wr(r1, p.memory.rb(p.r.pc + 1));
            p.r.pc += 2;
            p.clock.c += 12; },
        LDrrar: function(p, r1, r2, r3) { ops._LDav(p, GameboyJS.Util.getRegAddr(p, r1, r2), p.r[r3]);
            p.clock.c += 8; },
        LDrrra: function(p, r1, r2, r3) { p.wr(r1, p.memory.rb(GameboyJS.Util.getRegAddr(p, r2, r3)));
            p.clock.c += 8; },
        LDrn: function(p, r1) { p.wr(r1, p.memory.rb(p.r.pc++));
            p.clock.c += 8; },
        LDrr: function(p, r1, r2) { p.wr(r1, p.r[r2]);
            p.clock.c += 4; },
        LDrar: function(p, r1, r2) { p.memory.wb(p.r[r1] + 0xFF00, p.r[r2]);
            p.clock.c += 8; },
        LDrra: function(p, r1, r2) { p.wr(r1, p.memory.rb(p.r[r2] + 0xFF00));
            p.clock.c += 8; },
        LDspnn: function(p) { p.wr('sp', (p.memory.rb(p.r.pc + 1) << 8) + p.memory.rb(p.r.pc));
            p.r.pc += 2;
            p.clock.c += 12; },
        LDsprr: function(p, r1, r2) { p.wr('sp', GameboyJS.Util.getRegAddr(p, r1, r2));
            p.clock.c += 8; },
        LDnnar: function(p, r1) { var addr = (p.memory.rb(p.r.pc + 1) << 8) + p.memory.rb(p.r.pc);
            p.memory.wb(addr, p.r[r1]);
            p.r.pc += 2;
            p.clock.c += 16; },
        LDrnna: function(p, r1) { var addr = (p.memory.rb(p.r.pc + 1) << 8) + p.memory.rb(p.r.pc);
            p.wr(r1, p.memory.rb(addr));
            p.r.pc += 2;
            p.clock.c += 16; },
        LDrrspn: function(p, r1, r2) {
            var rel = p.memory.rb(p.r.pc++);
            rel = GameboyJS.Util.getSignedValue(rel);
            var val = p.r.sp + rel;
            var c = (p.r.sp & 0xFF) + (rel & 0xFF) > 0xFF;
            var h = (p.r.sp & 0xF) + (rel & 0xF) > 0xF;
            val &= 0xFFFF;
            var f = 0;
            if (h) f |= 0x20;
            if (c) f |= 0x10;
            p.wr('F', f);
            p.wr(r1, val >> 8);
            p.wr(r2, val & 0xFF);
            p.clock.c += 12;
        },
        LDnnsp: function(p) { var addr = p.memory.rb(p.r.pc++) + (p.memory.rb(p.r.pc++) << 8);
            ops._LDav(p, addr, p.r.sp & 0xFF);
            ops._LDav(p, addr + 1, p.r.sp >> 8);
            p.clock.c += 20; },
        LDrran: function(p, r1, r2) { var addr = GameboyJS.Util.getRegAddr(p, r1, r2);
            ops._LDav(p, addr, p.memory.rb(p.r.pc++));
            p.clock.c += 12; },
        _LDav: function(p, addr, val) { p.memory.wb(addr, val); },
        LDHnar: function(p, r1) { p.memory.wb(0xFF00 + p.memory.rb(p.r.pc++), p.r[r1]);
            p.clock.c += 12; },
        LDHrna: function(p, r1) { p.wr(r1, p.memory.rb(0xFF00 + p.memory.rb(p.r.pc++)));
            p.clock.c += 12; },
        INCrr: function(p, r1, r2) { p.wr(r2, (p.r[r2] + 1) & 0xFF); if (p.r[r2] == 0) p.wr(r1, (p.r[r1] + 1) & 0xFF);
            p.clock.c += 8; },
        INCrra: function(p, r1, r2) {
            var addr = GameboyJS.Util.getRegAddr(p, r1, r2);
            var val = (p.memory.rb(addr) + 1) & 0xFF;
            var z = val == 0;
            var h = (p.memory.rb(addr) & 0xF) + 1 > 0xF;
            p.memory.wb(addr, val);
            p.r.F &= 0x10;
            if (h) p.r.F |= 0x20;
            if (z) p.r.F |= 0x80;
            p.clock.c += 12;
        },
        INCsp: function(p) { p.wr('sp', p.r.sp + 1);
            p.r.sp &= 0xFFFF;
            p.clock.c += 8; },
        INCr: function(p, r1) {
            var h = ((p.r[r1] & 0xF) + 1) & 0x10;
            p.wr(r1, (p.r[r1] + 1) & 0xFF);
            var z = p.r[r1] == 0;
            p.r.F &= 0x10;
            if (h) p.r.F |= 0x20;
            if (z) p.r.F |= 0x80;
            p.clock.c += 4;
        },
        DECrr: function(p, r1, r2) { p.wr(r2, (p.r[r2] - 1) & 0xFF); if (p.r[r2] == 0xFF) p.wr(r1, (p.r[r1] - 1) & 0xFF);
            p.clock.c += 8; },
        DECsp: function(p) { p.wr('sp', p.r.sp - 1);
            p.r.sp &= 0xFFFF;
            p.clock.c += 8; },
        DECr: function(p, r1) {
            var h = (p.r[r1] & 0xF) < 1;
            p.wr(r1, (p.r[r1] - 1) & 0xFF);
            var z = p.r[r1] == 0;
            p.r.F &= 0x10;
            p.r.F |= 0x40;
            if (h) p.r.F |= 0x20;
            if (z) p.r.F |= 0x80;
            p.clock.c += 4;
        },
        DECrra: function(p, r1, r2) {
            var addr = GameboyJS.Util.getRegAddr(p, r1, r2);
            var val = (p.memory.rb(addr) - 1) & 0xFF;
            var z = val == 0;
            var h = (p.memory.rb(addr) & 0xF) < 1;
            p.memory.wb(addr, val);
            p.r.F &= 0x10;
            p.r.F |= 0x40;
            if (h) p.r.F |= 0x20;
            if (z) p.r.F |= 0x80;
            p.clock.c += 12;
        },
        ADDrr: function(p, r1, r2) { var n = p.r[r2];
            ops._ADDrn(p, r1, n);
            p.clock.c += 4; },
        ADDrn: function(p, r1) { var n = p.memory.rb(p.r.pc++);
            ops._ADDrn(p, r1, n);
            p.clock.c += 8; },
        _ADDrn: function(p, r1, n) {
            var h = ((p.r[r1] & 0xF) + (n & 0xF)) & 0x10;
            p.wr(r1, p.r[r1] + n);
            var c = p.r[r1] & 0x100;
            p.r[r1] &= 0xFF;
            var f = 0;
            if (p.r[r1] == 0) f |= 0x80;
            if (h) f |= 0x20;
            if (c) f |= 0x10;
            p.wr('F', f);
        },
        ADDrrrr: function(p, r1, r2, r3, r4) { ops._ADDrrn(p, r1, r2, (p.r[r3] << 8) + p.r[r4]);
            p.clock.c += 8; },
        ADDrrsp: function(p, r1, r2) { ops._ADDrrn(p, r1, r2, p.r.sp);
            p.clock.c += 8; },
        ADDspn: function(p) {
            var v = p.memory.rb(p.r.pc++);
            v = GameboyJS.Util.getSignedValue(v);
            var c = ((p.r.sp & 0xFF) + (v & 0xFF)) > 0xFF;
            var h = (p.r.sp & 0xF) + (v & 0xF) > 0xF;
            var f = 0;
            if (h) f |= 0x20;
            if (c) f |= 0x10;
            p.wr('F', f);
            p.wr('sp', (p.r.sp + v) & 0xFFFF);
            p.clock.c += 16;
        },
        _ADDrrn: function(p, r1, r2, n) {
            var v1 = (p.r[r1] << 8) + p.r[r2];
            var v2 = n;
            var res = v1 + v2;
            var c = res & 0x10000;
            var h = ((v1 & 0xFFF) + (v2 & 0xFFF)) & 0x1000;
            var z = p.r.F & 0x80;
            res &= 0xFFFF;
            p.r[r2] = res & 0xFF;
            res = res >> 8;
            p.r[r1] = res & 0xFF;
            var f = 0;
            if (z) f |= 0x80;
            if (h) f |= 0x20;
            if (c) f |= 0x10;
            p.r.F = f;
        },
        ADCrr: function(p, r1, r2) { var n = p.r[r2];
            ops._ADCrn(p, r1, n);
            p.clock.c += 4; },
        ADCrn: function(p, r1) { var n = p.memory.rb(p.r.pc++);
            ops._ADCrn(p, r1, n);
            p.clock.c += 8; },
        _ADCrn: function(p, r1, n) {
            var c = p.r.F & 0x10 ? 1 : 0;
            var h = ((p.r[r1] & 0xF) + (n & 0xF) + c) & 0x10;
            p.wr(r1, p.r[r1] + n + c);
            c = p.r[r1] & 0x100;
            p.r[r1] &= 0xFF;
            var f = 0;
            if (p.r[r1] == 0) f |= 0x80;
            if (h) f |= 0x20;
            if (c) f |= 0x10;
            p.r.F = f;
        },
        ADCrrra: function(p, r1, r2, r3) { var n = p.memory.rb(GameboyJS.Util.getRegAddr(p, r2, r3));
            ops._ADCrn(p, r1, n);
            p.clock.c += 8; },
        ADDrrra: function(p, r1, r2, r3) {
            var v = p.memory.rb(GameboyJS.Util.getRegAddr(p, r2, r3));
            var h = ((p.r[r1] & 0xF) + (v & 0xF)) & 0x10;
            p.wr(r1, p.r[r1] + v);
            var c = p.r[r1] & 0x100;
            p.r[r1] &= 0xFF;
            var f = 0;
            if (p.r[r1] == 0) f |= 0x80;
            if (h) f |= 0x20;
            if (c) f |= 0x10;
            p.wr('F', f);
            p.clock.c += 8;
        },
        SUBr: function(p, r1) { var n = p.r[r1];
            ops._SUBn(p, n);
            p.clock.c += 4; },
        SUBn: function(p) { var n = p.memory.rb(p.r.pc++);
            ops._SUBn(p, n);
            p.clock.c += 8; },
        SUBrra: function(p, r1, r2) { var n = p.memory.rb(GameboyJS.Util.getRegAddr(p, r1, r2));
            ops._SUBn(p, n);
            p.clock.c += 8; },
        _SUBn: function(p, n) {
            var c = p.r.A < n;
            var h = (p.r.A & 0xF) < (n & 0xF);
            p.wr('A', p.r.A - n);
            p.r.A &= 0xFF;
            var z = p.r.A == 0;
            var f = 0x40;
            if (z) f |= 0x80;
            if (h) f |= 0x20;
            if (c) f |= 0x10;
            p.wr('F', f);
        },
        SBCn: function(p) { var n = p.memory.rb(p.r.pc++);
            ops._SBCn(p, n);
            p.clock.c += 8; },
        SBCr: function(p, r1) { var n = p.r[r1];
            ops._SBCn(p, n);
            p.clock.c += 4; },
        SBCrra: function(p, r1, r2) { var v = p.memory.rb((p.r[r1] << 8) + p.r[r2]);
            ops._SBCn(p, v);
            p.clock.c += 8; },
        _SBCn: function(p, n) {
            var carry = p.r.F & 0x10 ? 1 : 0;
            var c = p.r.A < n + carry;
            var h = (p.r.A & 0xF) < (n & 0xF) + carry;
            p.wr('A', p.r.A - n - carry);
            p.r.A &= 0xFF;
            var z = p.r.A == 0;
            var f = 0x40;
            if (z) f |= 0x80;
            if (h) f |= 0x20;
            if (c) f |= 0x10;
            p.r.F = f;
        },
        ORr: function(p, r1) { p.r.A |= p.r[r1];
            p.r.F = (p.r.A == 0) ? 0x80 : 0x00;
            p.clock.c += 4; },
        ORn: function(p) { p.r.A |= p.memory.rb(p.r.pc++);
            p.r.F = (p.r.A == 0) ? 0x80 : 0x00;
            p.clock.c += 8; },
        ORrra: function(p, r1, r2) { p.r.A |= p.memory.rb((p.r[r1] << 8) + p.r[r2]);
            p.r.F = (p.r.A == 0) ? 0x80 : 0x00;
            p.clock.c += 8; },
        ANDr: function(p, r1) { p.r.A &= p.r[r1];
            p.r.F = (p.r.A == 0) ? 0xA0 : 0x20;
            p.clock.c += 4; },
        ANDn: function(p) { p.r.A &= p.memory.rb(p.r.pc++);
            p.r.F = (p.r.A == 0) ? 0xA0 : 0x20;
            p.clock.c += 8; },
        ANDrra: function(p, r1, r2) { p.r.A &= p.memory.rb(GameboyJS.Util.getRegAddr(p, r1, r2));
            p.r.F = (p.r.A == 0) ? 0xA0 : 0x20;
            p.clock.c += 8; },
        XORr: function(p, r1) { p.r.A ^= p.r[r1];
            p.r.F = (p.r.A == 0) ? 0x80 : 0x00;
            p.clock.c += 4; },
        XORn: function(p) { p.r.A ^= p.memory.rb(p.r.pc++);
            p.r.F = (p.r.A == 0) ? 0x80 : 0x00;
            p.clock.c += 8; },
        XORrra: function(p, r1, r2) { p.r.A ^= p.memory.rb((p.r[r1] << 8) + p.r[r2]);
            p.r.F = (p.r.A == 0) ? 0x80 : 0x00;
            p.clock.c += 8; },
        CPr: function(p, r1) { var n = p.r[r1];
            ops._CPn(p, n);
            p.clock.c += 4; },
        CPn: function(p) { var n = p.memory.rb(p.r.pc++);
            ops._CPn(p, n);
            p.clock.c += 8; },
        CPrra: function(p, r1, r2) { var n = p.memory.rb(GameboyJS.Util.getRegAddr(p, r1, r2));
            ops._CPn(p, n);
            p.clock.c += 8; },
        _CPn: function(p, n) {
            var c = p.r.A < n;
            var z = p.r.A == n;
            var h = (p.r.A & 0xF) < (n & 0xF);
            var f = 0x40;
            if (z) f += 0x80;
            if (h) f += 0x20;
            if (c) f += 0x10;
            p.r.F = f;
        },
        RRCr: function(p, r1) { p.r.F = 0; var out = p.r[r1] & 0x01; if (out) p.r.F |= 0x10;
            p.r[r1] = (p.r[r1] >> 1) | (out * 0x80); if (p.r[r1] == 0) p.r.F |= 0x80;
            p.clock.c += 4; },
        RRCrra: function(p, r1, r2) { var addr = GameboyJS.Util.getRegAddr(p, r1, r2);
            p.r.F = 0; var out = p.memory.rb(addr) & 0x01; if (out) p.r.F |= 0x10;
            p.memory.wb(addr, (p.memory.rb(addr) >> 1) | (out * 0x80)); if (p.memory.rb(addr) == 0) p.r.F |= 0x80;
            p.clock.c += 12; },
        RLCr: function(p, r1) { p.r.F = 0; var out = p.r[r1] & 0x80 ? 1 : 0; if (out) p.r.F |= 0x10;
            p.r[r1] = ((p.r[r1] << 1) + out) & 0xFF; if (p.r[r1] == 0) p.r.F |= 0x80;
            p.clock.c += 4; },
        RLCrra: function(p, r1, r2) { var addr = GameboyJS.Util.getRegAddr(p, r1, r2);
            p.r.F = 0; var out = p.memory.rb(addr) & 0x80 ? 1 : 0; if (out) p.r.F |= 0x10;
            p.memory.wb(addr, ((p.memory.rb(addr) << 1) + out) & 0xFF); if (p.memory.rb(addr) == 0) p.r.F |= 0x80;
            p.clock.c += 12; },
        RLr: function(p, r1) { var c = (p.r.F & 0x10) ? 1 : 0;
            p.r.F = 0; var out = p.r[r1] & 0x80;
            out ? p.r.F |= 0x10 : p.r.F &= 0xEF;
            p.r[r1] = ((p.r[r1] << 1) + c) & 0xFF; if (p.r[r1] == 0) p.r.F |= 0x80;
            p.clock.c += 4; },
        RLrra: function(p, r1, r2) { var addr = GameboyJS.Util.getRegAddr(p, r1, r2); var c = (p.r.F & 0x10) ? 1 : 0;
            p.r.F = 0; var out = p.memory.rb(addr) & 0x80;
            out ? p.r.F |= 0x10 : p.r.F &= 0xEF;
            p.memory.wb(addr, ((p.memory.rb(addr) << 1) + c) & 0xFF); if (p.memory.rb(addr) == 0) p.r.F |= 0x80;
            p.clock.c += 12; },
        RRr: function(p, r1) { var c = (p.r.F & 0x10) ? 1 : 0;
            p.r.F = 0; var out = p.r[r1] & 0x01;
            out ? p.r.F |= 0x10 : p.r.F &= 0xEF;
            p.r[r1] = (p.r[r1] >> 1) | (c * 0x80); if (p.r[r1] == 0) p.r.F |= 0x80;
            p.clock.c += 4; },
        RRrra: function(p, r1, r2) { var addr = GameboyJS.Util.getRegAddr(p, r1, r2); var c = (p.r.F & 0x10) ? 1 : 0;
            p.r.F = 0; var out = p.memory.rb(addr) & 0x01;
            out ? p.r.F |= 0x10 : p.r.F &= 0xEF;
            p.memory.wb(addr, (p.memory.rb(addr) >> 1) | (c * 0x80)); if (p.memory.rb(addr) == 0) p.r.F |= 0x80;
            p.clock.c += 12; },
        SRAr: function(p, r1) { p.r.F = 0; if (p.r[r1] & 0x01) p.r.F |= 0x10; var msb = p.r[r1] & 0x80;
            p.r[r1] = (p.r[r1] >> 1) | msb; if (p.r[r1] == 0) p.r.F |= 0x80;
            p.clock.c += 4; },
        SRArra: function(p, r1, r2) { var addr = GameboyJS.Util.getRegAddr(p, r1, r2);
            p.r.F = 0; if (p.memory.rb(addr) & 0x01) p.r.F |= 0x10; var msb = p.memory.rb(addr) & 0x80;
            p.memory.wb(addr, (p.memory.rb(addr) >> 1) | msb); if (p.memory.rb(addr) == 0) p.r.F |= 0x80;
            p.clock.c += 12; },
        SLAr: function(p, r1) { p.r.F = 0; if (p.r[r1] & 0x80) p.r.F |= 0x10;
            p.r[r1] = (p.r[r1] << 1) & 0xFF; if (p.r[r1] == 0) p.r.F |= 0x80;
            p.clock.c += 4; },
        SLArra: function(p, r1, r2) { var addr = GameboyJS.Util.getRegAddr(p, r1, r2);
            p.r.F = 0; if (p.memory.rb(addr) & 0x80) p.r.F |= 0x10;
            p.memory.wb(addr, (p.memory.rb(addr) << 1) & 0xFF); if (p.memory.rb(addr) == 0) p.r.F |= 0x80;
            p.clock.c += 12; },
        SRLr: function(p, r1) { p.r.F = 0; if (p.r[r1] & 0x01) p.r.F |= 0x10;
            p.r[r1] = p.r[r1] >> 1; if (p.r[r1] == 0) p.r.F |= 0x80;
            p.clock.c += 4; },
        SRLrra: function(p, r1, r2) { var addr = GameboyJS.Util.getRegAddr(p, r1, r2);
            p.r.F = 0; if (p.memory.rb(addr) & 0x01) p.r.F |= 0x10;
            p.memory.wb(addr, p.memory.rb(addr) >> 1); if (p.memory.rb(addr) == 0) p.r.F |= 0x80;
            p.clock.c += 12; },
        BITir: function(p, i, r1) { var mask = 1 << i; var z = (p.r[r1] & mask) ? 0 : 1; var f = p.r.F & 0x10;
            f |= 0x20; if (z) f |= 0x80;
            p.r.F = f;
            p.clock.c += 4; },
        BITirra: function(p, i, r1, r2) { var addr = GameboyJS.Util.getRegAddr(p, r1, r2); var mask = 1 << i; var z = (p.memory.rb(addr) & mask) ? 0 : 1; var f = p.r.F & 0x10;
            f |= 0x20; if (z) f |= 0x80;
            p.r.F = f;
            p.clock.c += 8; },
        SETir: function(p, i, r1) { var mask = 1 << i;
            p.r[r1] |= mask;
            p.clock.c += 4; },
        SETirra: function(p, i, r1, r2) { var addr = GameboyJS.Util.getRegAddr(p, r1, r2); var mask = 1 << i;
            p.memory.wb(addr, p.memory.rb(addr) | mask);
            p.clock.c += 12; },
        RESir: function(p, i, r1) { var mask = 0xFF - (1 << i);
            p.r[r1] &= mask;
            p.clock.c += 4; },
        RESirra: function(p, i, r1, r2) { var addr = GameboyJS.Util.getRegAddr(p, r1, r2); var mask = 0xFF - (1 << i);
            p.memory.wb(addr, p.memory.rb(addr) & mask);
            p.clock.c += 12; },
        SWAPr: function(p, r1) { p.r[r1] = ops._SWAPn(p, p.r[r1]);
            p.clock.c += 4; },
        SWAPrra: function(p, r1, r2) { var addr = (p.r[r1] << 8) + p.r[r2];
            p.memory.wb(addr, ops._SWAPn(p, p.memory.rb(addr)));
            p.clock.c += 12; },
        _SWAPn: function(p, n) { p.r.F = n == 0 ? 0x80 : 0; return ((n & 0xF0) >> 4) | ((n & 0x0F) << 4); },
        JPnn: function(p) { p.wr('pc', (p.memory.rb(p.r.pc + 1) << 8) + p.memory.rb(p.r.pc));
            p.clock.c += 16; },
        JRccn: function(p, cc) { if (GameboyJS.Util.testFlag(p, cc)) { var v = p.memory.rb(p.r.pc++);
                v = GameboyJS.Util.getSignedValue(v);
                p.r.pc += v;
                p.clock.c += 4; } else { p.r.pc++; }
            p.clock.c += 8; },
        JPccnn: function(p, cc) { if (GameboyJS.Util.testFlag(p, cc)) { p.wr('pc', (p.memory.rb(p.r.pc + 1) << 8) + p.memory.rb(p.r.pc));
                p.clock.c += 4; } else { p.r.pc += 2; }
            p.clock.c += 12; },
        JPrr: function(p, r1, r2) { p.r.pc = (p.r[r1] << 8) + p.r[r2];
            p.clock.c += 4; },
        JRn: function(p) { var v = p.memory.rb(p.r.pc++);
            v = GameboyJS.Util.getSignedValue(v);
            p.r.pc += v;
            p.clock.c += 12; },
        PUSHrr: function(p, r1, r2) { p.wr('sp', p.r.sp - 1);
            p.memory.wb(p.r.sp, p.r[r1]);
            p.wr('sp', p.r.sp - 1);
            p.memory.wb(p.r.sp, p.r[r2]);
            p.clock.c += 16; },
        POPrr: function(p, r1, r2) { p.wr(r2, p.memory.rb(p.r.sp));
            p.wr('sp', p.r.sp + 1);
            p.wr(r1, p.memory.rb(p.r.sp));
            p.wr('sp', p.r.sp + 1);
            p.clock.c += 12; },
        RSTn: function(p, n) { p.wr('sp', p.r.sp - 1);
            p.memory.wb(p.r.sp, p.r.pc >> 8);
            p.wr('sp', p.r.sp - 1);
            p.memory.wb(p.r.sp, p.r.pc & 0xFF);
            p.r.pc = n;
            p.clock.c += 16; },
        RET: function(p) { p.r.pc = p.memory.rb(p.r.sp);
            p.wr('sp', p.r.sp + 1);
            p.r.pc += p.memory.rb(p.r.sp) << 8;
            p.wr('sp', p.r.sp + 1);
            p.clock.c += 16; },
        RETcc: function(p, cc) { if (GameboyJS.Util.testFlag(p, cc)) { p.r.pc = p.memory.rb(p.r.sp);
                p.wr('sp', p.r.sp + 1);
                p.r.pc += p.memory.rb(p.r.sp) << 8;
                p.wr('sp', p.r.sp + 1);
                p.clock.c += 12; }
            p.clock.c += 8; },
        CALLnn: function(p) { ops._CALLnn(p);
            p.clock.c += 24; },
        CALLccnn: function(p, cc) { if (GameboyJS.Util.testFlag(p, cc)) { ops._CALLnn(p);
                p.clock.c += 12; } else { p.r.pc += 2; }
            p.clock.c += 12; },
        _CALLnn: function(p) {
            p.wr('sp', p.r.sp - 1);
            p.memory.wb(p.r.sp, ((p.r.pc + 2) & 0xFF00) >> 8);
            p.wr('sp', p.r.sp - 1);
            p.memory.wb(p.r.sp, (p.r.pc + 2) & 0x00FF);
            var j = p.memory.rb(p.r.pc) + (p.memory.rb(p.r.pc + 1) << 8);
            p.r.pc = j;
        },
        CPL: function(p) { p.wr('A', (~p.r.A) & 0xFF);
            p.r.F |= 0x60, p.clock.c += 4; },
        CCF: function(p) { p.r.F &= 0x9F;
            p.r.F & 0x10 ? p.r.F &= 0xE0 : p.r.F |= 0x10;
            p.clock.c += 4; },
        SCF: function(p) { p.r.F &= 0x9F;
            p.r.F |= 0x10;
            p.clock.c += 4; },
        DAA: function(p) {
            var sub = (p.r.F & 0x40) ? 1 : 0;
            var h = (p.r.F & 0x20) ? 1 : 0;
            var c = (p.r.F & 0x10) ? 1 : 0;
            if (sub) {
                if (h) {
                    p.r.A = (p.r.A - 0x6) & 0xFF;
                }
                if (c) {
                    p.r.A -= 0x60;
                }
            } else {
                if ((p.r.A & 0xF) > 9 || h) {
                    p.r.A += 0x6;
                }
                if (p.r.A > 0x9F || c) {
                    p.r.A += 0x60;
                }
            }
            if (p.r.A & 0x100) c = 1;

            p.r.A &= 0xFF;
            p.r.F &= 0x40;
            if (p.r.A == 0) p.r.F |= 0x80;
            if (c) p.r.F |= 0x10;
            p.clock.c += 4;
        },
        HALT: function(p) { p.halt();
            p.clock.c += 4; },
        DI: function(p) { p.disableInterrupts();
            p.clock.c += 4; },
        EI: function(p) { p.enableInterrupts();
            p.clock.c += 4; },
        RETI: function(p) { p.enableInterrupts();
            ops.RET(p); },
        CB: function(p) {
            var opcode = p.memory.rb(p.r.pc++);
            GameboyJS.opcodeCbmap[opcode](p);
            p.clock.c += 4;
        }
    };
    GameboyJS.cpuOps = ops;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    var defaultOptions = {
        pad: { class: GameboyJS.Keyboard, mapping: null },
        zoom: 1,
        romReaders: [],
        statusContainerId: 'status',
        gameNameContainerId: 'game-name',
        errorContainerId: 'error'
    };

    // Gameboy class
    //
    // This object is the entry point of the application
    // Will delegate user actions to the emulated devices
    // and provide information where needed
    var Gameboy = function(canvas, options) {
        options = options || {};
        this.options = GameboyJS.Util.extend({}, defaultOptions, options);

        var cpu = new GameboyJS.CPU(this);
        var screen = new GameboyJS.Screen(canvas, this.options.zoom);
        var gpu = new GameboyJS.GPU(screen, cpu);
        cpu.gpu = gpu;

        var pad = new this.options.pad.class(this.options.pad.mapping);
        var input = new GameboyJS.Input(cpu, pad);
        cpu.input = input;

        this.cpu = cpu;
        this.screen = screen;
        this.input = input;
        this.pad = pad;

        this.createRom(this.options.romReaders);

        this.statusContainer = document.getElementById(this.options.statusContainerId) || document.createElement('div');
        this.gameNameContainer = document.getElementById(this.options.gameNameContainerId) || document.createElement('div');
        this.errorContainer = document.getElementById(this.options.errorContainerId) || document.createElement('div');
    };

    // Create the ROM object and bind one or more readers
    Gameboy.prototype.createRom = function(readers) {
        var rom = new GameboyJS.Rom(this);
        if (readers.length == 0) {
            // add the default rom reader
            var romReader = new GameboyJS.RomFileReader();
            rom.addReader(romReader);
        } else {
            for (var i in readers) {
                if (readers.hasOwnProperty(i)) {
                    rom.addReader(readers[i]);
                }
            }
        }
    };

    Gameboy.prototype.startRom = function(rom) {
        this.errorContainer.classList.add('hide');
        this.cpu.reset();
        try {
            this.cpu.loadRom(rom.data);
            this.setStatus('Game Running :');
            this.setGameName(this.cpu.getGameName());
            this.cpu.run();
        } catch (e) {
            this.handleException(e);
        }
    };

    Gameboy.prototype.pause = function(value) {
        if (value) {
            this.setStatus('Game Paused :');
            this.cpu.pause();
        } else {
            this.setStatus('Game Running :');
            this.cpu.unpause();
        }
    };

    Gameboy.prototype.error = function(message) {
        this.setStatus('Error during execution');
        this.setError('An error occurred during execution:' + message);
        this.cpu.stop();
    };

    Gameboy.prototype.setStatus = function(status) {
        this.statusContainer.innerHTML = status;
    };
    // Display an error message
    Gameboy.prototype.setError = function(message) {
        this.errorContainer.classList.remove('hide');
        this.errorContainer.innerHTML = message;
    };
    // Display the name of the game running
    Gameboy.prototype.setGameName = function(name) {
        this.gameNameContainer.innerHTML = name;
    };
    Gameboy.prototype.setSoundEnabled = function(value) {
        if (value) {
            this.cpu.apu.connect();
        } else {
            this.cpu.apu.disconnect();
        }
    };
    Gameboy.prototype.setScreenZoom = function(value) {
        this.screen.setPixelSize(value);
    };
    Gameboy.prototype.handleException = function(e) {
        if (e instanceof GameboyJS.UnimplementedException) {
            if (e.fatal) {
                this.error('This cartridge is not supported (' + e.message + ')');
            } else {
                console.error(e.message);
            }
        } else {
            throw e;
        }
    };
    GameboyJS.Gameboy = Gameboy;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    // Memory bank controllers

    var MBC = {};

    // Create an MBC instance depending on the type specified in the cartridge
    MBC.getMbcInstance = function(memory, type) {
        var instance;
        switch (type) {
            case 0x00:
                instance = new MBC0(memory);
                break;
            case 0x01:
            case 0x02:
            case 0x03:
                instance = new MBC1(memory);
                break;
            case 0x0F:
            case 0x10:
            case 0x11:
            case 0x12:
            case 0x13:
                instance = new MBC3(memory);
                break;
            case 0x19:
            case 0x1A:
            case 0x1B:
            case 0x1C:
            case 0x1D:
            case 0x1E:
                instance = new MBC5(memory);
                break;
            default:
                throw new GameboyJS.UnimplementedException('MBC type not supported');
        }

        return instance;
    };

    var MBC1 = function(memory) {
        this.memory = memory;
        this.romBankNumber = 1;
        this.mode = 0; // mode 0 = ROM, mode 1 = RAM
        this.ramEnabled = true;
        this.extRam = new GameboyJS.ExtRam();
    };

    MBC1.prototype.loadRam = function(game, size) {
        this.extRam.loadRam(game, size);
    };

    MBC1.prototype.manageWrite = function(addr, value) {
        switch (addr & 0xF000) {
            case 0x0000:
            case 0x1000: // enable RAM
                this.ramEnabled = (value & 0x0A) ? true : false;
                if (this.ramEnabled) {
                    this.extRam.saveRamData();
                }
                break;
            case 0x2000:
            case 0x3000: // ROM bank number lower 5 bits
                value &= 0x1F;
                if (value == 0) value = 1;
                var mask = this.mode ? 0 : 0xE0;
                this.romBankNumber = (this.romBankNumber & mask) + value;
                this.memory.loadRomBank(this.romBankNumber);
                break;
            case 0x4000:
            case 0x5000: // RAM bank or high bits ROM
                value &= 0x03;
                if (this.mode == 0) { // ROM upper bits
                    this.romBankNumber = (this.romBankNumber & 0x1F) | (value << 5);
                    this.memory.loadRomBank(this.romBankNumber);
                } else { // RAM bank
                    this.extRam.setRamBank(value);
                }
                break;
            case 0x6000:
            case 0x7000: // ROM / RAM mode
                this.mode = value & 1;
                break;
            case 0xA000:
            case 0xB000:
                this.extRam.manageWrite(addr - 0xA000, value);
                break;
        }
    };
    MBC1.prototype.readRam = function(addr) {
        return this.extRam.manageRead(addr - 0xA000);
    };

    var MBC3 = function(memory) {
        this.memory = memory;
        this.romBankNumber = 1;
        this.ramEnabled = true;
        this.extRam = new GameboyJS.ExtRam();
    };

    MBC3.prototype.loadRam = function(game, size) {
        this.extRam.loadRam(game, size);
    };

    MBC3.prototype.manageWrite = function(addr, value) {
        switch (addr & 0xF000) {
            case 0x0000:
            case 0x1000: // enable RAM
                this.ramEnabled = (value & 0x0A) ? true : false;
                if (this.ramEnabled) {
                    this.extRam.saveRamData();
                }
                break;
            case 0x2000:
            case 0x3000: // ROM bank number
                value &= 0x7F;
                if (value == 0) value = 1;
                this.romBankNumber = value;
                this.memory.loadRomBank(this.romBankNumber);
                break;
            case 0x4000:
            case 0x5000: // RAM bank
                this.extRam.setRamBank(value);
                break;
            case 0x6000:
            case 0x7000: // Latch clock data
                throw new GameboyJS.UnimplementedException('cartridge clock not supported', false);
                break;
            case 0xA000:
            case 0xB000:
                this.extRam.manageWrite(addr - 0xA000, value);
                break;
        }
    };
    MBC3.prototype.readRam = function(addr) {
        return this.extRam.manageRead(addr - 0xA000);
    };

    // declare MBC5 for compatibility with most cartriges
    // does not support rumble feature
    var MBC5 = MBC3;

    // MBC0 exists for consistency and manages the no-MBC cartriges
    var MBC0 = function(memory) { this.memory = memory; };

    MBC0.prototype.manageWrite = function(addr, value) {
        this.memory.loadRomBank(value);
    };
    MBC0.prototype.readRam = function(addr) { return 0; };
    MBC0.prototype.loadRam = function() {};

    GameboyJS.MBC = MBC;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    // Memory unit
    var Memory = function(cpu) {
        this.MEM_SIZE = 65536; // 64KB

        this.MBCtype = 0;
        this.banksize = 0x4000;
        this.rom = null;
        this.mbc = null;
        this.cpu = cpu;
    };

    Memory.addresses = {
        VRAM_START: 0x8000,
        VRAM_END: 0x9FFF,

        EXTRAM_START: 0xA000,
        EXTRAM_END: 0xBFFF,

        OAM_START: 0xFE00,
        OAM_END: 0xFE9F,

        DEVICE_START: 0xFF00,
        DEVICE_END: 0xFF7F
    };

    // Memory can be accessed as an Array
    Memory.prototype = new Array();

    Memory.prototype.reset = function() {
        this.length = this.MEM_SIZE;
        for (var i = Memory.addresses.VRAM_START; i <= Memory.addresses.VRAM_END; i++) {
            this[i] = 0;
        }
        for (var i = Memory.addresses.DEVICE_START; i <= Memory.addresses.DEVICE_END; i++) {
            this[i] = 0;
        }
        this[0xFFFF] = 0;
    };

    Memory.prototype.setRomData = function(data) {
        this.rom = data;
        this.loadRomBank(0);
        this.mbc = GameboyJS.MBC.getMbcInstance(this, this[0x147]);
        this.loadRomBank(1);
        this.mbc.loadRam(this.cpu.getGameName(), this.cpu.getRamSize());
    };

    Memory.prototype.loadRomBank = function(index) {
        var start = index ? 0x4000 : 0x0;
        var romStart = index * 0x4000;
        for (var i = 0; i < this.banksize; i++) {
            this[i + start] = this.rom[romStart + i];
        }
    };

    // Video ram accessor
    Memory.prototype.vram = function(address) {
        if (address < Memory.addresses.VRAM_START || address > Memory.addresses.VRAM_END) {
            throw 'VRAM access in out of bounds address ' + address;
        }

        return this[address];
    };

    // OAM ram accessor
    Memory.prototype.oamram = function(address) {
        if (address < Memory.addresses.OAM_START || address > Memory.addresses.OAM_END) {
            throw 'OAMRAM access in out of bounds address ' + address;
        }

        return this[address];
    };

    // Device ram accessor
    Memory.prototype.deviceram = function(address, value) {
        if (address < Memory.addresses.DEVICERAM_START || address > Memory.addresses.DEVICERAM_END) {
            throw 'Device RAM access in out of bounds address ' + address;
        }
        if (typeof value === "undefined") {
            return this[address];
        } else {
            this[address] = value;
        }

    };

    // Memory read proxy function
    // Used to centralize memory read access
    Memory.prototype.rb = function(addr) {
        if (addr >= 0xFF10 && addr < 0xFF40) {
            var mask = apuMask[addr - 0xFF10];
            return this[addr] | mask;
        }
        if ((addr >= 0xA000 && addr < 0xC000)) {
            return this.mbc.readRam(addr);
        }
        return this[addr];
    };

    // Bitmasks for audio addresses reads
    var apuMask = [
        0x80, 0x3F, 0x00, 0xFF, 0xBF, // NR10-NR15
        0xFF, 0x3F, 0x00, 0xFF, 0xBF, // NR20-NR25
        0x7F, 0xFF, 0x9F, 0xFF, 0xBF, // NR30-NR35
        0xFF, 0xFF, 0x00, 0x00, 0xBF, // NR40-NR45
        0x00, 0x00, 0x70, // NR50-NR52
        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Wave RAM
        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
    ];

    // Memory write proxy function
    // Used to centralize memory writes and delegate specific behaviour
    // to the correct units
    Memory.prototype.wb = function(addr, value) {
        if (addr < 0x8000 || (addr >= 0xA000 && addr < 0xC000)) { // MBC
            this.mbc.manageWrite(addr, value);
        } else if (addr >= 0xFF10 && addr <= 0xFF3F) { // sound registers
            this.cpu.apu.manageWrite(addr, value);
        } else if (addr == 0xFF00) { // input register
            this[addr] = ((this[addr] & 0x0F) | (value & 0x30));
        } else {
            this[addr] = value;
            if ((addr & 0xFF00) == 0xFF00) {
                if (addr == 0xFF02) {
                    if (value & 0x80) {
                        this.cpu.enableSerialTransfer();
                    }
                }
                if (addr == 0xFF04) {
                    this.cpu.resetDivTimer();
                }
                if (addr == 0xFF46) { // OAM DMA transfer
                    this.dmaTransfer(value);
                }
            }
        }
    }

    // Start a DMA transfer (OAM data from cartrige to RAM)
    Memory.prototype.dmaTransfer = function(startAddressPrefix) {
        var startAddress = (startAddressPrefix << 8);
        for (var i = 0; i < 0xA0; i++) {
            this[Memory.addresses.OAM_START + i] = this[startAddress + i];
        }
    };

    GameboyJS.Memory = Memory;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    var ops = GameboyJS.cpuOps;
    // Each opcode (0 to 0xFF) is associated to a CPU operation
    // CPU operations are implemented separately
    // The cbmap object holds operations for CB prefixed opcodes (0xCB00 to 0xCBFF)
    // Non existent opcodes are commented out and marked empty
    var map = {
        0x00: function(p) { p.clock.c += 4; },
        0x01: function(p) { ops.LDrrnn(p, 'B', 'C'); },
        0x02: function(p) { ops.LDrrar(p, 'B', 'C', 'A'); },
        0x03: function(p) { ops.INCrr(p, 'B', 'C'); },
        0x04: function(p) { ops.INCr(p, 'B'); },
        0x05: function(p) { ops.DECr(p, 'B'); },
        0x06: function(p) { ops.LDrn(p, 'B'); },
        0x07: function(p) { var out = p.r.A & 0x80 ? 1 : 0;
            out ? p.r.F = 0x10 : p.r.F = 0;
            p.wr('A', ((p.r.A << 1) + out) & 0xFF);
            p.clock.c += 4; },
        0x08: function(p) { ops.LDnnsp(p); },
        0x09: function(p) { ops.ADDrrrr(p, 'H', 'L', 'B', 'C'); },
        0x0A: function(p) { ops.LDrrra(p, 'A', 'B', 'C'); },
        0x0B: function(p) { ops.DECrr(p, 'B', 'C'); },
        0x0C: function(p) { ops.INCr(p, 'C'); },
        0x0D: function(p) { ops.DECr(p, 'C'); },
        0x0E: function(p) { ops.LDrn(p, 'C'); },
        0x0F: function(p) { var out = p.r.A & 0x01;
            out ? p.r.F = 0x10 : p.r.F = 0;
            p.wr('A', (p.r.A >> 1) | (out * 0x80));
            p.clock.c += 4; },

        0x10: function(p) { p.r.pc++;
            p.clock.c += 4; },
        0x11: function(p) { ops.LDrrnn(p, 'D', 'E'); },
        0x12: function(p) { ops.LDrrar(p, 'D', 'E', 'A'); },
        0x13: function(p) { ops.INCrr(p, 'D', 'E'); },
        0x14: function(p) { ops.INCr(p, 'D'); },
        0x15: function(p) { ops.DECr(p, 'D'); },
        0x16: function(p) { ops.LDrn(p, 'D'); },
        0x17: function(p) { var c = (p.r.F & 0x10) ? 1 : 0; var out = p.r.A & 0x80 ? 1 : 0;
            out ? p.r.F = 0x10 : p.r.F = 0;
            p.wr('A', ((p.r.A << 1) + c) & 0xFF);
            p.clock.c += 4; },
        0x18: function(p) { ops.JRn(p); },
        0x19: function(p) { ops.ADDrrrr(p, 'H', 'L', 'D', 'E'); },
        0x1A: function(p) { ops.LDrrra(p, 'A', 'D', 'E'); },
        0x1B: function(p) { ops.DECrr(p, 'D', 'E'); },
        0x1C: function(p) { ops.INCr(p, 'E'); },
        0x1D: function(p) { ops.DECr(p, 'E'); },
        0x1E: function(p) { ops.LDrn(p, 'E'); },
        0x1F: function(p) { var c = (p.r.F & 0x10) ? 1 : 0; var out = p.r.A & 0x01;
            out ? p.r.F = 0x10 : p.r.F = 0;
            p.wr('A', (p.r.A >> 1) | (c * 0x80));
            p.clock.c += 4; },

        0x20: function(p) { ops.JRccn(p, 'NZ'); },
        0x21: function(p) { ops.LDrrnn(p, 'H', 'L'); },
        0x22: function(p) { ops.LDrrar(p, 'H', 'L', 'A');
            ops.INCrr(p, 'H', 'L');
            p.clock.c -= 8; },
        0x23: function(p) { ops.INCrr(p, 'H', 'L'); },
        0x24: function(p) { ops.INCr(p, 'H'); },
        0x25: function(p) { ops.DECr(p, 'H'); },
        0x26: function(p) { ops.LDrn(p, 'H'); },
        0x27: function(p) { ops.DAA(p); },
        0x28: function(p) { ops.JRccn(p, 'Z'); },
        0x29: function(p) { ops.ADDrrrr(p, 'H', 'L', 'H', 'L'); },
        0x2A: function(p) { ops.LDrrra(p, 'A', 'H', 'L');
            ops.INCrr(p, 'H', 'L');
            p.clock.c -= 8; },
        0x2B: function(p) { ops.DECrr(p, 'H', 'L'); },
        0x2C: function(p) { ops.INCr(p, 'L'); },
        0x2D: function(p) { ops.DECr(p, 'L'); },
        0x2E: function(p) { ops.LDrn(p, 'L'); },
        0x2F: function(p) { ops.CPL(p); },

        0x30: function(p) { ops.JRccn(p, 'NC'); },
        0x31: function(p) { ops.LDspnn(p); },
        0x32: function(p) { ops.LDrrar(p, 'H', 'L', 'A');
            ops.DECrr(p, 'H', 'L');
            p.clock.c -= 8; },
        0x33: function(p) { ops.INCsp(p); },
        0x34: function(p) { ops.INCrra(p, 'H', 'L'); },
        0x35: function(p) { ops.DECrra(p, 'H', 'L'); },
        0x36: function(p) { ops.LDrran(p, 'H', 'L'); },
        0x37: function(p) { ops.SCF(p); },
        0x38: function(p) { ops.JRccn(p, 'C'); },
        0x39: function(p) { ops.ADDrrsp(p, 'H', 'L'); },
        0x3A: function(p) { ops.LDrrra(p, 'A', 'H', 'L');
            ops.DECrr(p, 'H', 'L');
            p.clock.c -= 8; },
        0x3B: function(p) { ops.DECsp(p); },
        0x3C: function(p) { ops.INCr(p, 'A'); },
        0x3D: function(p) { ops.DECr(p, 'A'); },
        0x3E: function(p) { ops.LDrn(p, 'A'); },
        0x3F: function(p) { ops.CCF(p); },

        0x40: function(p) { ops.LDrr(p, 'B', 'B'); },
        0x41: function(p) { ops.LDrr(p, 'B', 'C'); },
        0x42: function(p) { ops.LDrr(p, 'B', 'D'); },
        0x43: function(p) { ops.LDrr(p, 'B', 'E'); },
        0x44: function(p) { ops.LDrr(p, 'B', 'H'); },
        0x45: function(p) { ops.LDrr(p, 'B', 'L'); },
        0x46: function(p) { ops.LDrrra(p, 'B', 'H', 'L'); },
        0x47: function(p) { ops.LDrr(p, 'B', 'A'); },
        0x48: function(p) { ops.LDrr(p, 'C', 'B'); },
        0x49: function(p) { ops.LDrr(p, 'C', 'C'); },
        0x4A: function(p) { ops.LDrr(p, 'C', 'D'); },
        0x4B: function(p) { ops.LDrr(p, 'C', 'E'); },
        0x4C: function(p) { ops.LDrr(p, 'C', 'H'); },
        0x4D: function(p) { ops.LDrr(p, 'C', 'L'); },
        0x4E: function(p) { ops.LDrrra(p, 'C', 'H', 'L'); },
        0x4F: function(p) { ops.LDrr(p, 'C', 'A'); },

        0x50: function(p) { ops.LDrr(p, 'D', 'B'); },
        0x51: function(p) { ops.LDrr(p, 'D', 'C'); },
        0x52: function(p) { ops.LDrr(p, 'D', 'D'); },
        0x53: function(p) { ops.LDrr(p, 'D', 'E'); },
        0x54: function(p) { ops.LDrr(p, 'D', 'H'); },
        0x55: function(p) { ops.LDrr(p, 'D', 'L'); },
        0x56: function(p) { ops.LDrrra(p, 'D', 'H', 'L'); },
        0x57: function(p) { ops.LDrr(p, 'D', 'A'); },
        0x58: function(p) { ops.LDrr(p, 'E', 'B'); },
        0x59: function(p) { ops.LDrr(p, 'E', 'C'); },
        0x5A: function(p) { ops.LDrr(p, 'E', 'D'); },
        0x5B: function(p) { ops.LDrr(p, 'E', 'E'); },
        0x5C: function(p) { ops.LDrr(p, 'E', 'H'); },
        0x5D: function(p) { ops.LDrr(p, 'E', 'L'); },
        0x5E: function(p) { ops.LDrrra(p, 'E', 'H', 'L'); },
        0x5F: function(p) { ops.LDrr(p, 'E', 'A'); },

        0x60: function(p) { ops.LDrr(p, 'H', 'B'); },
        0x61: function(p) { ops.LDrr(p, 'H', 'C'); },
        0x62: function(p) { ops.LDrr(p, 'H', 'D'); },
        0x63: function(p) { ops.LDrr(p, 'H', 'E'); },
        0x64: function(p) { ops.LDrr(p, 'H', 'H'); },
        0x65: function(p) { ops.LDrr(p, 'H', 'L'); },
        0x66: function(p) { ops.LDrrra(p, 'H', 'H', 'L'); },
        0x67: function(p) { ops.LDrr(p, 'H', 'A'); },
        0x68: function(p) { ops.LDrr(p, 'L', 'B'); },
        0x69: function(p) { ops.LDrr(p, 'L', 'C'); },
        0x6A: function(p) { ops.LDrr(p, 'L', 'D'); },
        0x6B: function(p) { ops.LDrr(p, 'L', 'E'); },
        0x6C: function(p) { ops.LDrr(p, 'L', 'H'); },
        0x6D: function(p) { ops.LDrr(p, 'L', 'L'); },
        0x6E: function(p) { ops.LDrrra(p, 'L', 'H', 'L'); },
        0x6F: function(p) { ops.LDrr(p, 'L', 'A'); },

        0x70: function(p) { ops.LDrrar(p, 'H', 'L', 'B'); },
        0x71: function(p) { ops.LDrrar(p, 'H', 'L', 'C'); },
        0x72: function(p) { ops.LDrrar(p, 'H', 'L', 'D'); },
        0x73: function(p) { ops.LDrrar(p, 'H', 'L', 'E'); },
        0x74: function(p) { ops.LDrrar(p, 'H', 'L', 'H'); },
        0x75: function(p) { ops.LDrrar(p, 'H', 'L', 'L'); },
        0x76: function(p) { ops.HALT(p); },
        0x77: function(p) { ops.LDrrar(p, 'H', 'L', 'A'); },
        0x78: function(p) { ops.LDrr(p, 'A', 'B'); },
        0x79: function(p) { ops.LDrr(p, 'A', 'C'); },
        0x7A: function(p) { ops.LDrr(p, 'A', 'D'); },
        0x7B: function(p) { ops.LDrr(p, 'A', 'E'); },
        0x7C: function(p) { ops.LDrr(p, 'A', 'H'); },
        0x7D: function(p) { ops.LDrr(p, 'A', 'L'); },
        0x7E: function(p) { ops.LDrrra(p, 'A', 'H', 'L'); },
        0x7F: function(p) { ops.LDrr(p, 'A', 'A'); },

        0x80: function(p) { ops.ADDrr(p, 'A', 'B'); },
        0x81: function(p) { ops.ADDrr(p, 'A', 'C'); },
        0x82: function(p) { ops.ADDrr(p, 'A', 'D'); },
        0x83: function(p) { ops.ADDrr(p, 'A', 'E'); },
        0x84: function(p) { ops.ADDrr(p, 'A', 'H'); },
        0x85: function(p) { ops.ADDrr(p, 'A', 'L'); },
        0x86: function(p) { ops.ADDrrra(p, 'A', 'H', 'L'); },
        0x87: function(p) { ops.ADDrr(p, 'A', 'A'); },
        0x88: function(p) { ops.ADCrr(p, 'A', 'B'); },
        0x89: function(p) { ops.ADCrr(p, 'A', 'C'); },
        0x8A: function(p) { ops.ADCrr(p, 'A', 'D'); },
        0x8B: function(p) { ops.ADCrr(p, 'A', 'E'); },
        0x8C: function(p) { ops.ADCrr(p, 'A', 'H'); },
        0x8D: function(p) { ops.ADCrr(p, 'A', 'L'); },
        0x8E: function(p) { ops.ADCrrra(p, 'A', 'H', 'L'); },
        0x8F: function(p) { ops.ADCrr(p, 'A', 'A'); },

        0x90: function(p) { ops.SUBr(p, 'B'); },
        0x91: function(p) { ops.SUBr(p, 'C'); },
        0x92: function(p) { ops.SUBr(p, 'D'); },
        0x93: function(p) { ops.SUBr(p, 'E'); },
        0x94: function(p) { ops.SUBr(p, 'H'); },
        0x95: function(p) { ops.SUBr(p, 'L'); },
        0x96: function(p) { ops.SUBrra(p, 'H', 'L'); },
        0x97: function(p) { ops.SUBr(p, 'A'); },
        0x98: function(p) { ops.SBCr(p, 'B'); },
        0x99: function(p) { ops.SBCr(p, 'C'); },
        0x9A: function(p) { ops.SBCr(p, 'D'); },
        0x9B: function(p) { ops.SBCr(p, 'E'); },
        0x9C: function(p) { ops.SBCr(p, 'H'); },
        0x9D: function(p) { ops.SBCr(p, 'L'); },
        0x9E: function(p) { ops.SBCrra(p, 'H', 'L'); },
        0x9F: function(p) { ops.SBCr(p, 'A'); },

        0xA0: function(p) { ops.ANDr(p, 'B'); },
        0xA1: function(p) { ops.ANDr(p, 'C'); },
        0xA2: function(p) { ops.ANDr(p, 'D'); },
        0xA3: function(p) { ops.ANDr(p, 'E'); },
        0xA4: function(p) { ops.ANDr(p, 'H'); },
        0xA5: function(p) { ops.ANDr(p, 'L'); },
        0xA6: function(p) { ops.ANDrra(p, 'H', 'L'); },
        0xA7: function(p) { ops.ANDr(p, 'A'); },
        0xA8: function(p) { ops.XORr(p, 'B'); },
        0xA9: function(p) { ops.XORr(p, 'C'); },
        0xAA: function(p) { ops.XORr(p, 'D'); },
        0xAB: function(p) { ops.XORr(p, 'E'); },
        0xAC: function(p) { ops.XORr(p, 'H'); },
        0xAD: function(p) { ops.XORr(p, 'L'); },
        0xAE: function(p) { ops.XORrra(p, 'H', 'L'); },
        0xAF: function(p) { ops.XORr(p, 'A'); },

        0xB0: function(p) { ops.ORr(p, 'B'); },
        0xB1: function(p) { ops.ORr(p, 'C'); },
        0xB2: function(p) { ops.ORr(p, 'D'); },
        0xB3: function(p) { ops.ORr(p, 'E'); },
        0xB4: function(p) { ops.ORr(p, 'H'); },
        0xB5: function(p) { ops.ORr(p, 'L'); },
        0xB6: function(p) { ops.ORrra(p, 'H', 'L'); },
        0xB7: function(p) { ops.ORr(p, 'A'); },
        0xB8: function(p) { ops.CPr(p, 'B'); },
        0xB9: function(p) { ops.CPr(p, 'C'); },
        0xBA: function(p) { ops.CPr(p, 'D'); },
        0xBB: function(p) { ops.CPr(p, 'E'); },
        0xBC: function(p) { ops.CPr(p, 'H'); },
        0xBD: function(p) { ops.CPr(p, 'L'); },
        0xBE: function(p) { ops.CPrra(p, 'H', 'L'); },
        0xBF: function(p) { ops.CPr(p, 'A'); },

        0xC0: function(p) { ops.RETcc(p, 'NZ'); },
        0xC1: function(p) { ops.POPrr(p, 'B', 'C'); },
        0xC2: function(p) { ops.JPccnn(p, 'NZ'); },
        0xC3: function(p) { ops.JPnn(p); },
        0xC4: function(p) { ops.CALLccnn(p, 'NZ'); },
        0xC5: function(p) { ops.PUSHrr(p, 'B', 'C'); },
        0xC6: function(p) { ops.ADDrn(p, 'A'); },
        0xC7: function(p) { ops.RSTn(p, 0x00); },
        0xC8: function(p) { ops.RETcc(p, 'Z'); },
        0xC9: function(p) { ops.RET(p); },
        0xCA: function(p) { ops.JPccnn(p, 'Z'); },
        0xCB: function(p) { ops.CB(p); },
        0xCC: function(p) { ops.CALLccnn(p, 'Z'); },
        0xCD: function(p) { ops.CALLnn(p); },
        0xCE: function(p) { ops.ADCrn(p, 'A'); },
        0xCF: function(p) { ops.RSTn(p, 0x08); },

        0xD0: function(p) { ops.RETcc(p, 'NC'); },
        0xD1: function(p) { ops.POPrr(p, 'D', 'E'); },
        0xD2: function(p) { ops.JPccnn(p, 'NC'); },
        //0xD3 empty
        0xD4: function(p) { ops.CALLccnn(p, 'NC'); },
        0xD5: function(p) { ops.PUSHrr(p, 'D', 'E'); },
        0xD6: function(p) { ops.SUBn(p); },
        0xD7: function(p) { ops.RSTn(p, 0x10); },
        0xD8: function(p) { ops.RETcc(p, 'C'); },
        0xD9: function(p) { ops.RETI(p); },
        0xDA: function(p) { ops.JPccnn(p, 'C'); },
        //0xDB empty
        0xDC: function(p) { ops.CALLccnn(p, 'C'); },
        //0xDD empty
        0xDE: function(p) { ops.SBCn(p); },
        0xDF: function(p) { ops.RSTn(p, 0x18); },

        0xE0: function(p) { ops.LDHnar(p, 'A'); },
        0xE1: function(p) { ops.POPrr(p, 'H', 'L'); },
        0xE2: function(p) { ops.LDrar(p, 'C', 'A'); },
        //0xE3 empty
        //0xE4 empty
        0xE5: function(p) { ops.PUSHrr(p, 'H', 'L'); },
        0xE6: function(p) { ops.ANDn(p); },
        0xE7: function(p) { ops.RSTn(p, 0x20); },
        0xE8: function(p) { ops.ADDspn(p); },
        0xE9: function(p) { ops.JPrr(p, 'H', 'L'); },
        0xEA: function(p) { ops.LDnnar(p, 'A'); },
        //0xEB empty
        //0xEC empty
        //0xED empty
        0xEE: function(p) { ops.XORn(p); },
        0xEF: function(p) { ops.RSTn(p, 0x28); },

        0xF0: function(p) { ops.LDHrna(p, 'A'); },
        0xF1: function(p) { ops.POPrr(p, 'A', 'F'); },
        0xF2: function(p) { ops.LDrra(p, 'A', 'C'); },
        0xF3: function(p) { ops.DI(p); },
        //0xF4 empty
        0xF5: function(p) { ops.PUSHrr(p, 'A', 'F'); },
        0xF6: function(p) { ops.ORn(p); },
        0xF7: function(p) { ops.RSTn(p, 0x30); },
        0xF8: function(p) { ops.LDrrspn(p, 'H', 'L'); },
        0xF9: function(p) { ops.LDsprr(p, 'H', 'L'); },
        0xFA: function(p) { ops.LDrnna(p, 'A'); },
        0xFB: function(p) { ops.EI(p); },
        //0xFC empty
        //0xFD empty
        0xFE: function(p) { ops.CPn(p); },
        0xFF: function(p) { ops.RSTn(p, 0x38); }
    };

    var cbmap = {
        0x00: function(p) { ops.RLCr(p, 'B'); },
        0x01: function(p) { ops.RLCr(p, 'C'); },
        0x02: function(p) { ops.RLCr(p, 'D'); },
        0x03: function(p) { ops.RLCr(p, 'E'); },
        0x04: function(p) { ops.RLCr(p, 'H'); },
        0x05: function(p) { ops.RLCr(p, 'L'); },
        0x06: function(p) { ops.RLCrra(p, 'H', 'L'); },
        0x07: function(p) { ops.RLCr(p, 'A'); },
        0x08: function(p) { ops.RRCr(p, 'B'); },
        0x09: function(p) { ops.RRCr(p, 'C'); },
        0x0A: function(p) { ops.RRCr(p, 'D'); },
        0x0B: function(p) { ops.RRCr(p, 'E'); },
        0x0C: function(p) { ops.RRCr(p, 'H'); },
        0x0D: function(p) { ops.RRCr(p, 'L'); },
        0x0E: function(p) { ops.RRCrra(p, 'H', 'L'); },
        0x0F: function(p) { ops.RRCr(p, 'A'); },

        0x10: function(p) { ops.RLr(p, 'B'); },
        0x11: function(p) { ops.RLr(p, 'C'); },
        0x12: function(p) { ops.RLr(p, 'D'); },
        0x13: function(p) { ops.RLr(p, 'E'); },
        0x14: function(p) { ops.RLr(p, 'H'); },
        0x15: function(p) { ops.RLr(p, 'L'); },
        0x16: function(p) { ops.RLrra(p, 'H', 'L'); },
        0x17: function(p) { ops.RLr(p, 'A'); },
        0x18: function(p) { ops.RRr(p, 'B'); },
        0x19: function(p) { ops.RRr(p, 'C'); },
        0x1A: function(p) { ops.RRr(p, 'D'); },
        0x1B: function(p) { ops.RRr(p, 'E'); },
        0x1C: function(p) { ops.RRr(p, 'H'); },
        0x1D: function(p) { ops.RRr(p, 'L'); },
        0x1E: function(p) { ops.RRrra(p, 'H', 'L'); },
        0x1F: function(p) { ops.RRr(p, 'A'); },

        0x20: function(p) { ops.SLAr(p, 'B'); },
        0x21: function(p) { ops.SLAr(p, 'C'); },
        0x22: function(p) { ops.SLAr(p, 'D'); },
        0x23: function(p) { ops.SLAr(p, 'E'); },
        0x24: function(p) { ops.SLAr(p, 'H'); },
        0x25: function(p) { ops.SLAr(p, 'L'); },
        0x26: function(p) { ops.SLArra(p, 'H', 'L'); },
        0x27: function(p) { ops.SLAr(p, 'A'); },
        0x28: function(p) { ops.SRAr(p, 'B'); },
        0x29: function(p) { ops.SRAr(p, 'C'); },
        0x2A: function(p) { ops.SRAr(p, 'D'); },
        0x2B: function(p) { ops.SRAr(p, 'E'); },
        0x2C: function(p) { ops.SRAr(p, 'H'); },
        0x2D: function(p) { ops.SRAr(p, 'L'); },
        0x2E: function(p) { ops.SRArra(p, 'H', 'L'); },
        0x2F: function(p) { ops.SRAr(p, 'A'); },

        0x30: function(p) { ops.SWAPr(p, 'B'); },
        0x31: function(p) { ops.SWAPr(p, 'C'); },
        0x32: function(p) { ops.SWAPr(p, 'D'); },
        0x33: function(p) { ops.SWAPr(p, 'E'); },
        0x34: function(p) { ops.SWAPr(p, 'H'); },
        0x35: function(p) { ops.SWAPr(p, 'L'); },
        0x36: function(p) { ops.SWAPrra(p, 'H', 'L'); },
        0x37: function(p) { ops.SWAPr(p, 'A'); },
        0x38: function(p) { ops.SRLr(p, 'B'); },
        0x39: function(p) { ops.SRLr(p, 'C'); },
        0x3A: function(p) { ops.SRLr(p, 'D'); },
        0x3B: function(p) { ops.SRLr(p, 'E'); },
        0x3C: function(p) { ops.SRLr(p, 'H'); },
        0x3D: function(p) { ops.SRLr(p, 'L'); },
        0x3E: function(p) { ops.SRLrra(p, 'H', 'L'); },
        0x3F: function(p) { ops.SRLr(p, 'A'); },

        0x40: function(p) { ops.BITir(p, 0, 'B'); },
        0x41: function(p) { ops.BITir(p, 0, 'C'); },
        0x42: function(p) { ops.BITir(p, 0, 'D'); },
        0x43: function(p) { ops.BITir(p, 0, 'E'); },
        0x44: function(p) { ops.BITir(p, 0, 'H'); },
        0x45: function(p) { ops.BITir(p, 0, 'L'); },
        0x46: function(p) { ops.BITirra(p, 0, 'H', 'L'); },
        0x47: function(p) { ops.BITir(p, 0, 'A'); },
        0x48: function(p) { ops.BITir(p, 1, 'B'); },
        0x49: function(p) { ops.BITir(p, 1, 'C'); },
        0x4A: function(p) { ops.BITir(p, 1, 'D'); },
        0x4B: function(p) { ops.BITir(p, 1, 'E'); },
        0x4C: function(p) { ops.BITir(p, 1, 'H'); },
        0x4D: function(p) { ops.BITir(p, 1, 'L'); },
        0x4E: function(p) { ops.BITirra(p, 1, 'H', 'L'); },
        0x4F: function(p) { ops.BITir(p, 1, 'A'); },

        0x50: function(p) { ops.BITir(p, 2, 'B'); },
        0x51: function(p) { ops.BITir(p, 2, 'C'); },
        0x52: function(p) { ops.BITir(p, 2, 'D'); },
        0x53: function(p) { ops.BITir(p, 2, 'E'); },
        0x54: function(p) { ops.BITir(p, 2, 'H'); },
        0x55: function(p) { ops.BITir(p, 2, 'L'); },
        0x56: function(p) { ops.BITirra(p, 2, 'H', 'L'); },
        0x57: function(p) { ops.BITir(p, 2, 'A'); },
        0x58: function(p) { ops.BITir(p, 3, 'B'); },
        0x59: function(p) { ops.BITir(p, 3, 'C'); },
        0x5A: function(p) { ops.BITir(p, 3, 'D'); },
        0x5B: function(p) { ops.BITir(p, 3, 'E'); },
        0x5C: function(p) { ops.BITir(p, 3, 'H'); },
        0x5D: function(p) { ops.BITir(p, 3, 'L'); },
        0x5E: function(p) { ops.BITirra(p, 3, 'H', 'L'); },
        0x5F: function(p) { ops.BITir(p, 3, 'A'); },

        0x60: function(p) { ops.BITir(p, 4, 'B'); },
        0x61: function(p) { ops.BITir(p, 4, 'C'); },
        0x62: function(p) { ops.BITir(p, 4, 'D'); },
        0x63: function(p) { ops.BITir(p, 4, 'E'); },
        0x64: function(p) { ops.BITir(p, 4, 'H'); },
        0x65: function(p) { ops.BITir(p, 4, 'L'); },
        0x66: function(p) { ops.BITirra(p, 4, 'H', 'L'); },
        0x67: function(p) { ops.BITir(p, 4, 'A'); },
        0x68: function(p) { ops.BITir(p, 5, 'B'); },
        0x69: function(p) { ops.BITir(p, 5, 'C'); },
        0x6A: function(p) { ops.BITir(p, 5, 'D'); },
        0x6B: function(p) { ops.BITir(p, 5, 'E'); },
        0x6C: function(p) { ops.BITir(p, 5, 'H'); },
        0x6D: function(p) { ops.BITir(p, 5, 'L'); },
        0x6E: function(p) { ops.BITirra(p, 5, 'H', 'L'); },
        0x6F: function(p) { ops.BITir(p, 5, 'A'); },

        0x70: function(p) { ops.BITir(p, 6, 'B'); },
        0x71: function(p) { ops.BITir(p, 6, 'C'); },
        0x72: function(p) { ops.BITir(p, 6, 'D'); },
        0x73: function(p) { ops.BITir(p, 6, 'E'); },
        0x74: function(p) { ops.BITir(p, 6, 'H'); },
        0x75: function(p) { ops.BITir(p, 6, 'L'); },
        0x76: function(p) { ops.BITirra(p, 6, 'H', 'L'); },
        0x77: function(p) { ops.BITir(p, 6, 'A'); },
        0x78: function(p) { ops.BITir(p, 7, 'B'); },
        0x79: function(p) { ops.BITir(p, 7, 'C'); },
        0x7A: function(p) { ops.BITir(p, 7, 'D'); },
        0x7B: function(p) { ops.BITir(p, 7, 'E'); },
        0x7C: function(p) { ops.BITir(p, 7, 'H'); },
        0x7D: function(p) { ops.BITir(p, 7, 'L'); },
        0x7E: function(p) { ops.BITirra(p, 7, 'H', 'L'); },
        0x7F: function(p) { ops.BITir(p, 7, 'A'); },

        0x80: function(p) { ops.RESir(p, 0, 'B'); },
        0x81: function(p) { ops.RESir(p, 0, 'C'); },
        0x82: function(p) { ops.RESir(p, 0, 'D'); },
        0x83: function(p) { ops.RESir(p, 0, 'E'); },
        0x84: function(p) { ops.RESir(p, 0, 'H'); },
        0x85: function(p) { ops.RESir(p, 0, 'L'); },
        0x86: function(p) { ops.RESirra(p, 0, 'H', 'L'); },
        0x87: function(p) { ops.RESir(p, 0, 'A'); },
        0x88: function(p) { ops.RESir(p, 1, 'B'); },
        0x89: function(p) { ops.RESir(p, 1, 'C'); },
        0x8A: function(p) { ops.RESir(p, 1, 'D'); },
        0x8B: function(p) { ops.RESir(p, 1, 'E'); },
        0x8C: function(p) { ops.RESir(p, 1, 'H'); },
        0x8D: function(p) { ops.RESir(p, 1, 'L'); },
        0x8E: function(p) { ops.RESirra(p, 1, 'H', 'L'); },
        0x8F: function(p) { ops.RESir(p, 1, 'A'); },

        0x90: function(p) { ops.RESir(p, 2, 'B'); },
        0x91: function(p) { ops.RESir(p, 2, 'C'); },
        0x92: function(p) { ops.RESir(p, 2, 'D'); },
        0x93: function(p) { ops.RESir(p, 2, 'E'); },
        0x94: function(p) { ops.RESir(p, 2, 'H'); },
        0x95: function(p) { ops.RESir(p, 2, 'L'); },
        0x96: function(p) { ops.RESirra(p, 2, 'H', 'L'); },
        0x97: function(p) { ops.RESir(p, 2, 'A'); },
        0x98: function(p) { ops.RESir(p, 3, 'B'); },
        0x99: function(p) { ops.RESir(p, 3, 'C'); },
        0x9A: function(p) { ops.RESir(p, 3, 'D'); },
        0x9B: function(p) { ops.RESir(p, 3, 'E'); },
        0x9C: function(p) { ops.RESir(p, 3, 'H'); },
        0x9D: function(p) { ops.RESir(p, 3, 'L'); },
        0x9E: function(p) { ops.RESirra(p, 3, 'H', 'L'); },
        0x9F: function(p) { ops.RESir(p, 3, 'A'); },

        0xA0: function(p) { ops.RESir(p, 4, 'B'); },
        0xA1: function(p) { ops.RESir(p, 4, 'C'); },
        0xA2: function(p) { ops.RESir(p, 4, 'D'); },
        0xA3: function(p) { ops.RESir(p, 4, 'E'); },
        0xA4: function(p) { ops.RESir(p, 4, 'H'); },
        0xA5: function(p) { ops.RESir(p, 4, 'L'); },
        0xA6: function(p) { ops.RESirra(p, 4, 'H', 'L'); },
        0xA7: function(p) { ops.RESir(p, 4, 'A'); },
        0xA8: function(p) { ops.RESir(p, 5, 'B'); },
        0xA9: function(p) { ops.RESir(p, 5, 'C'); },
        0xAA: function(p) { ops.RESir(p, 5, 'D'); },
        0xAB: function(p) { ops.RESir(p, 5, 'E'); },
        0xAC: function(p) { ops.RESir(p, 5, 'H'); },
        0xAD: function(p) { ops.RESir(p, 5, 'L'); },
        0xAE: function(p) { ops.RESirra(p, 5, 'H', 'L'); },
        0xAF: function(p) { ops.RESir(p, 5, 'A'); },

        0xB0: function(p) { ops.RESir(p, 6, 'B'); },
        0xB1: function(p) { ops.RESir(p, 6, 'C'); },
        0xB2: function(p) { ops.RESir(p, 6, 'D'); },
        0xB3: function(p) { ops.RESir(p, 6, 'E'); },
        0xB4: function(p) { ops.RESir(p, 6, 'H'); },
        0xB5: function(p) { ops.RESir(p, 6, 'L'); },
        0xB6: function(p) { ops.RESirra(p, 6, 'H', 'L'); },
        0xB7: function(p) { ops.RESir(p, 6, 'A'); },
        0xB8: function(p) { ops.RESir(p, 7, 'B'); },
        0xB9: function(p) { ops.RESir(p, 7, 'C'); },
        0xBA: function(p) { ops.RESir(p, 7, 'D'); },
        0xBB: function(p) { ops.RESir(p, 7, 'E'); },
        0xBC: function(p) { ops.RESir(p, 7, 'H'); },
        0xBD: function(p) { ops.RESir(p, 7, 'L'); },
        0xBE: function(p) { ops.RESirra(p, 7, 'H', 'L'); },
        0xBF: function(p) { ops.RESir(p, 7, 'A'); },

        0xC0: function(p) { ops.SETir(p, 0, 'B'); },
        0xC1: function(p) { ops.SETir(p, 0, 'C'); },
        0xC2: function(p) { ops.SETir(p, 0, 'D'); },
        0xC3: function(p) { ops.SETir(p, 0, 'E'); },
        0xC4: function(p) { ops.SETir(p, 0, 'H'); },
        0xC5: function(p) { ops.SETir(p, 0, 'L'); },
        0xC6: function(p) { ops.SETirra(p, 0, 'H', 'L'); },
        0xC7: function(p) { ops.SETir(p, 0, 'A'); },
        0xC8: function(p) { ops.SETir(p, 1, 'B'); },
        0xC9: function(p) { ops.SETir(p, 1, 'C'); },
        0xCA: function(p) { ops.SETir(p, 1, 'D'); },
        0xCB: function(p) { ops.SETir(p, 1, 'E'); },
        0xCC: function(p) { ops.SETir(p, 1, 'H'); },
        0xCD: function(p) { ops.SETir(p, 1, 'L'); },
        0xCE: function(p) { ops.SETirra(p, 1, 'H', 'L'); },
        0xCF: function(p) { ops.SETir(p, 1, 'A'); },

        0xD0: function(p) { ops.SETir(p, 2, 'B'); },
        0xD1: function(p) { ops.SETir(p, 2, 'C'); },
        0xD2: function(p) { ops.SETir(p, 2, 'D'); },
        0xD3: function(p) { ops.SETir(p, 2, 'E'); },
        0xD4: function(p) { ops.SETir(p, 2, 'H'); },
        0xD5: function(p) { ops.SETir(p, 2, 'L'); },
        0xD6: function(p) { ops.SETirra(p, 2, 'H', 'L'); },
        0xD7: function(p) { ops.SETir(p, 2, 'A'); },
        0xD8: function(p) { ops.SETir(p, 3, 'B'); },
        0xD9: function(p) { ops.SETir(p, 3, 'C'); },
        0xDA: function(p) { ops.SETir(p, 3, 'D'); },
        0xDB: function(p) { ops.SETir(p, 3, 'E'); },
        0xDC: function(p) { ops.SETir(p, 3, 'H'); },
        0xDD: function(p) { ops.SETir(p, 3, 'L'); },
        0xDE: function(p) { ops.SETirra(p, 3, 'H', 'L'); },
        0xDF: function(p) { ops.SETir(p, 3, 'A'); },

        0xE0: function(p) { ops.SETir(p, 4, 'B'); },
        0xE1: function(p) { ops.SETir(p, 4, 'C'); },
        0xE2: function(p) { ops.SETir(p, 4, 'D'); },
        0xE3: function(p) { ops.SETir(p, 4, 'E'); },
        0xE4: function(p) { ops.SETir(p, 4, 'H'); },
        0xE5: function(p) { ops.SETir(p, 4, 'L'); },
        0xE6: function(p) { ops.SETirra(p, 4, 'H', 'L'); },
        0xE7: function(p) { ops.SETir(p, 4, 'A'); },
        0xE8: function(p) { ops.SETir(p, 5, 'B'); },
        0xE9: function(p) { ops.SETir(p, 5, 'C'); },
        0xEA: function(p) { ops.SETir(p, 5, 'D'); },
        0xEB: function(p) { ops.SETir(p, 5, 'E'); },
        0xEC: function(p) { ops.SETir(p, 5, 'H'); },
        0xED: function(p) { ops.SETir(p, 5, 'L'); },
        0xEE: function(p) { ops.SETirra(p, 5, 'H', 'L'); },
        0xEF: function(p) { ops.SETir(p, 5, 'A'); },

        0xF0: function(p) { ops.SETir(p, 6, 'B'); },
        0xF1: function(p) { ops.SETir(p, 6, 'C'); },
        0xF2: function(p) { ops.SETir(p, 6, 'D'); },
        0xF3: function(p) { ops.SETir(p, 6, 'E'); },
        0xF4: function(p) { ops.SETir(p, 6, 'H'); },
        0xF5: function(p) { ops.SETir(p, 6, 'L'); },
        0xF6: function(p) { ops.SETirra(p, 6, 'H', 'L'); },
        0xF7: function(p) { ops.SETir(p, 6, 'A'); },
        0xF8: function(p) { ops.SETir(p, 7, 'B'); },
        0xF9: function(p) { ops.SETir(p, 7, 'C'); },
        0xFA: function(p) { ops.SETir(p, 7, 'D'); },
        0xFB: function(p) { ops.SETir(p, 7, 'E'); },
        0xFC: function(p) { ops.SETir(p, 7, 'H'); },
        0xFD: function(p) { ops.SETir(p, 7, 'L'); },
        0xFE: function(p) { ops.SETirra(p, 7, 'H', 'L'); },
        0xFF: function(p) { ops.SETir(p, 7, 'A'); }
    };
    GameboyJS.opcodeMap = map;
    GameboyJS.opcodeCbmap = cbmap;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    // A RomAjaxReader is able to load a file through an AJAX request
    var RomAjaxReader = function() {

    };

    // The callback argument will be called when a file is successfully
    // read, with the data as argument (Uint8Array)
    RomAjaxReader.prototype.setCallback = function(onLoadCallback) {
        this.callback = onLoadCallback;
    };

    // This function should be called by application code
    // and will trigger the AJAX call itself and push data to the ROM object
    RomAjaxReader.prototype.loadFromUrl = function(url) {
        if (!url) {
            throw 'No url has been set in order to load a ROM file.';
        }
        var cb = this.callback;

        var xhr = new XMLHttpRequest();
        xhr.open('GET', url, true);
        xhr.responseType = "arraybuffer";
        xhr.onload = function() {
            var rom = new Uint8Array(xhr.response);
            cb && cb(rom);
        };

        xhr.send();
    };

    GameboyJS.RomAjaxReader = RomAjaxReader;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    // A RomDropFileReader is able to load a drag and dropped file
    var RomDropFileReader = function(el) {
        this.dropElement = el;
        if (!this.dropElement) {
            throw 'The RomDropFileReader needs a drop zone.';
        }

        var self = this;
        this.dropElement.addEventListener('dragenter', function(e) {
            e.preventDefault();
            e.target.classList.add('drag-active');
        });
        this.dropElement.addEventListener('dragleave', function(e) {
            e.preventDefault();
            e.target.classList.remove('drag-active');
        });
        this.dropElement.addEventListener('dragover', function(e) {
            e.preventDefault();
        });
        this.dropElement.addEventListener('drop', function(e) {
            e.target.classList.remove('drag-active');
            if (e.dataTransfer.files.length == 0) {
                return;
            }
            e.preventDefault();
            self.loadFromFile(e.dataTransfer.files[0]);
        });
    };

    // The callback argument will be called when a file is successfully
    // read, with the data as argument (Uint8Array)
    RomDropFileReader.prototype.setCallback = function(onLoadCallback) {
        this.callback = onLoadCallback;
    };

    // The file loading logic is the same as the regular file reader
    RomDropFileReader.prototype.loadFromFile = function(file) {
        if (file === undefined) {
            return;
        }
        var fr = new FileReader();
        var cb = this.callback;

        fr.onload = function() {
            cb && cb(new Uint8Array(fr.result));
        };
        fr.onerror = function(e) {
            console.log('Error reading the file', e.target.error.code)
        };
        fr.readAsArrayBuffer(file);
    };

    GameboyJS.RomDropFileReader = RomDropFileReader;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    // A RomFileReader is able to load a local file from an input element
    //
    // Expects to be provided a file input element,
    // or will try to find one with the "file" DOM ID
    var RomFileReader = function(el) {
        this.domElement = el || document.getElementById('file');
        if (!this.domElement) {
            throw 'The RomFileReader needs a valid input element.';
        }

        var self = this;
        this.domElement.addEventListener('change', function(e) {
            self.loadFromFile(e.target.files[0]);
        });
    };

    // The callback argument will be called when a file is successfully
    // read, with the data as argument (Uint8Array)
    RomFileReader.prototype.setCallback = function(onLoadCallback) {
        this.callback = onLoadCallback;
    };

    // Automatically called when the DOM input is provided with a file
    RomFileReader.prototype.loadFromFile = function(file) {
        if (file === undefined) {
            return;
        }
        var fr = new FileReader();
        var cb = this.callback;

        fr.onload = function() {
            cb && cb(new Uint8Array(fr.result));
        };
        fr.onerror = function(e) {
            console.log('Error reading the file', e.target.error.code)
        };
        fr.readAsArrayBuffer(file);
    };

    GameboyJS.RomFileReader = RomFileReader;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";


    var Rom = function(gameboy, romReader) {
        this.gameboy = gameboy;
        if (romReader) {
            this.addReader(romReader);
        }
    };

    Rom.prototype.addReader = function(romReader) {
        var self = this;
        romReader.setCallback(function(data) {
            if (!validate(data)) {
                self.gameboy.error('The file is not a valid GameBoy ROM.');
                return;
            }
            self.data = data;
            self.gameboy.startRom(self);
        });
    };

    // Validate the checksum of the cartridge header
    function validate(data) {
        var hash = 0;
        for (var i = 0x134; i <= 0x14C; i++) {
            hash = hash - data[i] - 1;
        }
        return (hash & 0xFF) == data[0x14D];
    };

    GameboyJS.Rom = Rom;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    // Handlers for the Serial port of the Gameboy

    // The ConsoleSerial is an output-only serial port
    // designed for debug purposes as some test roms output data on the serial port
    //
    // Will regularly output the received byte (converted to string) in the console logs
    // This handler always push the value 0xFF as an input
    var ConsoleSerial = {
        current: '',
        timeout: null,
        out: function(data) {
            ConsoleSerial.current += String.fromCharCode(data);
            if (data == 10) {
                ConsoleSerial.print();
            } else {
                clearTimeout(ConsoleSerial.timeout);
                ConsoleSerial.timeout = setTimeout(ConsoleSerial.print, 500);
            }
        },
        in: function() {
            return 0xFF;
        },
        print: function() {
            clearTimeout(ConsoleSerial.timeout);
            console.log('serial: ' + ConsoleSerial.current);
            ConsoleSerial.current = '';
        }
    };
    GameboyJS.ConsoleSerial = ConsoleSerial;

    // A DummySerial outputs nothing and always inputs 0xFF
    var DummySerial = {
        out: function() {},
        in: function() {
            return 0xFF;
        }
    };
    GameboyJS.DummySerial = DummySerial;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    // Audio Processing unit
    // Listens the write accesses to the audio-reserved memory addresses
    // and dispatches the data to the sound channels
    var APU = function(memory) {
        this.memory = memory;
        this.enabled = false;

        AudioContext = window.AudioContext || window.webkitAudioContext;
        var audioContext = new AudioContext();

        this.channel1 = new GameboyJS.Channel1(this, 1, audioContext);
        this.channel2 = new GameboyJS.Channel1(this, 2, audioContext);
        this.channel3 = new GameboyJS.Channel3(this, 3, audioContext);
        this.channel4 = new GameboyJS.Channel4(this, 4, audioContext);

    };
    APU.prototype.connect = function() {
        this.channel1.enable();
        this.channel2.enable();
        this.channel3.enable();
    };
    APU.prototype.disconnect = function() {
        this.channel1.disable();
        this.channel2.disable();
        this.channel3.disable();
    };
    // Updates the states of each channel given the elapsed time
    // (in instructions) since last update
    APU.prototype.update = function(clockElapsed) {
        if (this.enabled == false) return;

        this.channel1.update(clockElapsed);
        this.channel2.update(clockElapsed);
        this.channel3.update(clockElapsed);
        this.channel4.update(clockElapsed);
    };
    APU.prototype.setSoundFlag = function(channel, value) {
        var mask = 0xFF - (1 << (channel - 1));
        value = value << (channel - 1)
        var byteValue = this.memory.rb(APU.registers.NR52);
        byteValue &= mask;
        byteValue |= value;
        this.memory[APU.registers.NR52] = byteValue;
    };
    // Manage writes to audio registers
    // Will update the channels depending on the address
    APU.prototype.manageWrite = function(addr, value) {
        if (this.enabled == false && addr < APU.registers.NR52) {
            return;
        }
        this.memory[addr] = value;

        switch (addr) {
            // Channel 1 addresses
            case 0xFF10:
                this.channel1.clockSweep = 0;
                this.channel1.sweepTime = ((value & 0x70) >> 4);
                this.channel1.sweepSign = (value & 0x08) ? -1 : 1;
                this.channel1.sweepShifts = (value & 0x07);
                this.channel1.sweepCount = this.channel1.sweepShifts;
                break;
            case 0xFF11:
                // todo : bits 6-7
                this.channel1.setLength(value & 0x3F);
                break;
            case 0xFF12:
                this.channel1.envelopeSign = (value & 0x08) ? 1 : -1;
                var envelopeVolume = (value & 0xF0) >> 4;
                this.channel1.setEnvelopeVolume(envelopeVolume);
                this.channel1.envelopeStep = (value & 0x07);
                break;
            case 0xFF13:
                var frequency = this.channel1.getFrequency();
                frequency &= 0xF00;
                frequency |= value;
                this.channel1.setFrequency(frequency);
                break;
            case 0xFF14:
                var frequency = this.channel1.getFrequency();
                frequency &= 0xFF;
                frequency |= (value & 7) << 8;
                this.channel1.setFrequency(frequency);
                this.channel1.lengthCheck = (value & 0x40) ? true : false;
                if (value & 0x80) this.channel1.play();
                break;

                // Channel 2 addresses
            case 0xFF16:
                // todo : bits 6-7
                this.channel2.setLength(value & 0x3F);
                break;
            case 0xFF17:
                this.channel2.envelopeSign = (value & 0x08) ? 1 : -1;
                var envelopeVolume = (value & 0xF0) >> 4;
                this.channel2.setEnvelopeVolume(envelopeVolume);
                this.channel2.envelopeStep = (value & 0x07);
                break;
            case 0xFF18:
                var frequency = this.channel2.getFrequency();
                frequency &= 0xF00;
                frequency |= value;
                this.channel2.setFrequency(frequency);
                break;
            case 0xFF19:
                var frequency = this.channel2.getFrequency();
                frequency &= 0xFF;
                frequency |= (value & 7) << 8;
                this.channel2.setFrequency(frequency);
                this.channel2.lengthCheck = (value & 0x40) ? true : false;
                if (value & 0x80) {
                    this.channel2.play();
                }
                break;

                // Channel 3 addresses
            case 0xFF1A:
                // todo
                break;
            case 0xFF1B:
                this.channel3.setLength(value);
                break;
            case 0xFF1C:
                // todo
                break;
            case 0xFF1D:
                var frequency = this.channel3.getFrequency();
                frequency &= 0xF00;
                frequency |= value;
                this.channel3.setFrequency(frequency);
                break;
            case 0xFF1E:
                var frequency = this.channel3.getFrequency();
                frequency &= 0xFF;
                frequency |= (value & 7) << 8;
                this.channel3.setFrequency(frequency);
                this.channel3.lengthCheck = (value & 0x40) ? true : false;
                if (value & 0x80) {
                    this.channel3.play();
                }
                break;

                // Channel 4 addresses
            case 0xFF20:
                this.channel4.setLength(value & 0x3F);
                break;
            case 0xFF21:
                // todo
                break;
            case 0xFF22:
                // todo
                break;
            case 0xFF23:
                this.channel4.lengthCheck = (value & 0x40) ? true : false;
                if (value & 0x80) {
                    this.channel4.play();
                }
                break;

                // channel 3 wave bytes
            case 0xFF30:
            case 0xFF31:
            case 0xFF32:
            case 0xFF33:
            case 0xFF34:
            case 0xFF35:
            case 0xFF36:
            case 0xFF37:
            case 0xFF38:
            case 0xFF39:
            case 0xFF3A:
            case 0xFF3B:
            case 0xFF3C:
            case 0xFF3D:
            case 0xFF3E:
            case 0xFF3F:
                var index = addr - 0xFF30;
                this.channel3.setWaveBufferByte(index, value);
                break;

                // general audio switch
            case 0xFF26:
                value &= 0xF0;
                this.memory[addr] = value;
                this.enabled = (value & 0x80) == 0 ? false : true;
                if (!this.enabled) {
                    for (var i = 0xFF10; i < 0xFF27; i++)
                        this.memory[i] = 0;
                    // todo stop sound
                }
                break;
        }
    };

    APU.registers = {
        NR10: 0xFF10,
        NR11: 0xFF11,
        NR12: 0xFF12,
        NR13: 0xFF13,
        NR14: 0xFF14,

        NR21: 0xFF16,
        NR22: 0xFF17,
        NR23: 0xFF18,
        NR24: 0xFF19,

        NR30: 0xFF1A,
        NR31: 0xFF1B,
        NR32: 0xFF1C,
        NR33: 0xFF1D,
        NR34: 0xFF1E,

        NR41: 0xFF20,
        NR42: 0xFF21,
        NR43: 0xFF22,
        NR44: 0xFF23,

        NR50: 0xFF24,
        NR51: 0xFF25,
        NR52: 0xFF26
    };
    GameboyJS.APU = APU;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";
    var Channel1 = function(apu, channelNumber, audioContext) {
        this.apu = apu;
        this.channelNumber = channelNumber;
        this.playing = false;

        this.soundLengthUnit = 0x4000; // 1 / 256 second of instructions
        this.soundLength = 64; // defaults to 64 periods
        this.lengthCheck = false;

        this.sweepTime = 0; // from 0 to 7
        this.sweepStepLength = 0x8000; // 1 / 128 seconds of instructions
        this.sweepCount = 0;
        this.sweepShifts = 0;
        this.sweepSign = 1; // +1 / -1 for increase / decrease freq

        this.frequency = 0;

        this.envelopeStep = 0;
        this.envelopeStepLength = 0x10000; // 1 / 64 seconds of instructions
        this.envelopeCheck = false;
        this.envelopeSign = 1;

        this.clockLength = 0;
        this.clockEnvelop = 0;
        this.clockSweep = 0;

        var gainNode = audioContext.createGain();
        gainNode.gain.value = 0;
        var oscillator = audioContext.createOscillator();
        oscillator.type = 'square';
        oscillator.frequency.value = 1000;
        oscillator.connect(gainNode);
        oscillator.start(0);

        this.audioContext = audioContext;
        this.gainNode = gainNode;
        this.oscillator = oscillator;
    };

    Channel1.prototype.play = function() {
        if (this.playing) return;
        this.playing = true;
        this.apu.setSoundFlag(this.channelNumber, 1);
        this.gainNode.connect(this.audioContext.destination);
        this.clockLength = 0;
        this.clockEnvelop = 0;
        this.clockSweep = 0;
        if (this.sweepShifts > 0) this.checkFreqSweep();
    };
    Channel1.prototype.stop = function() {
        this.playing = false;
        this.apu.setSoundFlag(this.channelNumber, 0);
        this.gainNode.disconnect();
    };
    Channel1.prototype.checkFreqSweep = function() {
        var oldFreq = this.getFrequency();
        var newFreq = oldFreq + this.sweepSign * (oldFreq >> this.sweepShifts);
        if (newFreq > 0x7FF) {
            newFreq = 0;
            this.stop();
        }

        return newFreq;
    };
    Channel1.prototype.update = function(clockElapsed) {
        this.clockEnvelop += clockElapsed;
        this.clockSweep += clockElapsed;

        if ((this.sweepCount || this.sweepTime) && this.clockSweep > (this.sweepStepLength * this.sweepTime)) {
            this.clockSweep -= (this.sweepStepLength * this.sweepTime);
            this.sweepCount--;

            var newFreq = this.checkFreqSweep(); // process and check new freq

            this.apu.memory[0xFF13] = newFreq & 0xFF;
            this.apu.memory[0xFF14] &= 0xF8;
            this.apu.memory[0xFF14] |= (newFreq & 0x700) >> 8;
            this.setFrequency(newFreq);

            this.checkFreqSweep(); // check again with new value
        }

        if (this.envelopeCheck && this.clockEnvelop > this.envelopeStepLength) {
            this.clockEnvelop -= this.envelopeStepLength;
            this.envelopeStep--;
            this.setEnvelopeVolume(this.envelopeVolume + this.envelopeSign);
            if (this.envelopeStep <= 0) {
                this.envelopeCheck = false;
            }
        }

        if (this.lengthCheck) {
            this.clockLength += clockElapsed;
            if (this.clockLength > this.soundLengthUnit) {
                this.soundLength--;
                this.clockLength -= this.soundLengthUnit;
                if (this.soundLength == 0) {
                    this.setLength(0);
                    this.stop();
                }
            }
        }
    };
    Channel1.prototype.setFrequency = function(value) {
        this.frequency = value;
        this.oscillator.frequency.value = 131072 / (2048 - this.frequency);
    };
    Channel1.prototype.getFrequency = function() {
        return this.frequency;
    };
    Channel1.prototype.setLength = function(value) {
        this.soundLength = 64 - (value & 0x3F);
    };
    Channel1.prototype.setEnvelopeVolume = function(volume) {
        this.envelopeCheck = volume > 0 && volume < 16 ? true : false;
        this.envelopeVolume = volume;
        this.gainNode.gain.value = this.envelopeVolume * 1 / 100;
    };
    Channel1.prototype.disable = function() {
        this.oscillator.disconnect();
    };
    Channel1.prototype.enable = function() {
        this.oscillator.connect(this.gainNode);
    };
    GameboyJS.Channel1 = Channel1;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";
    var Channel3 = function(apu, channelNumber, audioContext) {
        this.apu = apu;
        this.channelNumber = channelNumber;
        this.playing = false;

        this.soundLength = 0;
        this.soundLengthUnit = 0x4000; // 1 / 256 second of instructions
        this.lengthCheck = false;

        this.clockLength = 0;

        this.buffer = new Float32Array(32);

        var gainNode = audioContext.createGain();
        gainNode.gain.value = 1;
        this.gainNode = gainNode;

        this.baseSpeed = 65536;
        var waveBuffer = audioContext.createBuffer(1, 32, this.baseSpeed);

        var bufferSource = audioContext.createBufferSource();
        bufferSource.buffer = waveBuffer;
        bufferSource.loop = true;
        bufferSource.connect(gainNode);
        bufferSource.start(0);

        this.audioContext = audioContext;
        this.waveBuffer = waveBuffer;
        this.bufferSource = bufferSource;

    };
    Channel3.prototype.play = function() {
        if (this.playing) return;
        this.playing = true;
        this.apu.setSoundFlag(this.channelNumber, 1);
        this.waveBuffer.copyToChannel(this.buffer, 0, 0);

        this.gainNode.connect(this.audioContext.destination);
        this.clockLength = 0;
    };
    Channel3.prototype.stop = function() {
        this.playing = false;
        this.apu.setSoundFlag(this.channelNumber, 0);
        this.gainNode.disconnect();
    };
    Channel3.prototype.update = function(clockElapsed) {
        if (this.lengthCheck) {
            this.clockLength += clockElapsed;
            if (this.clockLength > this.soundLengthUnit) {
                this.soundLength--;
                this.clockLength -= this.soundLengthUnit;
                if (this.soundLength == 0) {
                    this.setLength(0);
                    this.stop();
                }
            }
        }
    };
    Channel3.prototype.setFrequency = function(value) {
        value = 65536 / (2048 - value);
        this.bufferSource.playbackRate.value = value / this.baseSpeed;
    };
    Channel3.prototype.getFrequency = function() {
        var freq = 2048 - 65536 / (this.bufferSource.playbackRate.value * this.baseSpeed);
        return freq | 1;
    };
    Channel3.prototype.setLength = function(value) {
        this.soundLength = 256 - value;
    };
    Channel3.prototype.setWaveBufferByte = function(index, value) {
        var bufferIndex = index * 2;

        this.buffer[bufferIndex] = (value >> 4) / 8 - 1; // value in buffer is in -1 -> 1
        this.buffer[bufferIndex + 1] = (value & 0x0F) / 8 - 1;
    };
    Channel3.prototype.disable = function() {
        this.bufferSource.disconnect();
    };
    Channel3.prototype.enable = function() {
        this.bufferSource.connect(this.gainNode);
    };
    GameboyJS.Channel3 = Channel3;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";
    var Channel4 = function(apu, channelNumber, audioContext) {
        this.apu = apu;
        this.channelNumber = channelNumber;
        this.playing = false;

        this.soundLengthUnit = 0x4000; // 1 / 256 second of instructions
        this.soundLength = 64; // defaults to 64 periods
        this.lengthCheck = false;

        this.clockLength = 0;

        this.audioContext = audioContext;
    };

    Channel4.prototype.play = function() {
        if (this.playing) return;
        this.playing = true;
        this.apu.setSoundFlag(this.channelNumber, 1);
        this.clockLength = 0;
    };
    Channel4.prototype.stop = function() {
        this.playing = false;
        this.apu.setSoundFlag(this.channelNumber, 0);
    };
    Channel4.prototype.update = function(clockElapsed) {
        if (this.lengthCheck) {
            this.clockLength += clockElapsed;
            if (this.clockLength > this.soundLengthUnit) {
                this.soundLength--;
                this.clockLength -= this.soundLengthUnit;
                if (this.soundLength == 0) {
                    this.setLength(0);
                    this.stop();
                }
            }
        }
    };
    Channel4.prototype.setLength = function(value) {
        this.soundLength = 64 - (value & 0x3F);
    };
    GameboyJS.Channel4 = Channel4;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    var Timer = function(cpu, memory) {
        this.cpu = cpu;
        this.memory = memory;

        this.DIV = 0xFF04;
        this.TIMA = 0xFF05;
        this.TMA = 0xFF06;
        this.TAC = 0xFF07;

        this.mainTime = 0;
        this.divTime = 0;
    };

    Timer.prototype.update = function(clockElapsed) {
        this.updateDiv(clockElapsed);
        this.updateTimer(clockElapsed);
    };

    Timer.prototype.updateTimer = function(clockElapsed) {
        if (!(this.memory.rb(this.TAC) & 0x4)) {
            return;
        }
        this.mainTime += clockElapsed;

        var threshold = 64;
        switch (this.memory.rb(this.TAC) & 3) {
            case 0:
                threshold = 64;
                break; // 4KHz
            case 1:
                threshold = 1;
                break; // 256KHz
            case 2:
                threshold = 4;
                break; // 64KHz
            case 3:
                threshold = 16;
                break; // 16KHz
        }
        threshold *= 16;

        while (this.mainTime >= threshold) {
            this.mainTime -= threshold;

            this.memory.wb(this.TIMA, this.memory.rb(this.TIMA) + 1);
            if (this.memory.rb(this.TIMA) > 0xFF) {
                this.memory.wb(this.TIMA, this.memory.rb(this.TMA));
                this.cpu.requestInterrupt(GameboyJS.CPU.INTERRUPTS.TIMER);
            }
        }
    };
    // Update the DIV register internal clock
    // Increment it if the clock threshold is elapsed and
    // reset it if its value overflows
    Timer.prototype.updateDiv = function(clockElapsed) {
        var divThreshold = 256; // DIV is 16KHz
        this.divTime += clockElapsed;
        if (this.divTime > divThreshold) {
            this.divTime -= divThreshold;
            var div = this.memory.rb(this.DIV) + 1;
            this.memory.wb(this.DIV, div & 0xFF);
        }
    };

    Timer.prototype.resetDiv = function() {
        this.divTime = 0;
        this.memory[this.DIV] = 0; // direct write to avoid looping
    };
    GameboyJS.Timer = Timer;
}(GameboyJS || (GameboyJS = {})));

var GameboyJS;
(function(GameboyJS) {
    "use strict";

    // Utility functions
    var Util = {
        // Add to the first argument the properties of all other arguments
        extend: function(target /*, source1, source2, etc. */ ) {
            var sources = Array.prototype.slice.call(arguments);
            for (var i in sources) {
                var source = sources[i];
                for (var name in source) {
                    target[name] = source[name];
                }
            }

            return target;
        },
        testFlag: function(p, cc) {
            var test = 1;
            var mask = 0x10;
            if (cc == 'NZ' || cc == 'NC') test = 0;
            if (cc == 'NZ' || cc == 'Z') mask = 0x80;
            return (test && p.r.F & mask) || (!test && !(p.r.F & mask));
        },
        getRegAddr: function(p, r1, r2) { return Util.makeword(p.r[r1], p.r[r2]); },

        // make a 16 bits word from 2 bytes
        makeword: function(b1, b2) { return (b1 << 8) + b2; },

        // return the integer signed value of a given byte
        getSignedValue: function(v) { return v & 0x80 ? v - 256 : v; },

        // extract a bit from a byte
        readBit: function(byte, index) {
            return (byte >> index) & 1;
        }
    };

    GameboyJS.Util = Util;
}(GameboyJS || (GameboyJS = {})));