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mappers.js
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mappers.js
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/*
JSNES, based on Jamie Sanders' vNES
Copyright (C) 2010 Ben Firshman
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
JSNES.Mappers = {};
JSNES.Mappers[0] = function(nes) {
this.nes = nes;
};
JSNES.Mappers[0].prototype = {
reset: function() {
this.joy1StrobeState = 0;
this.joy2StrobeState = 0;
this.joypadLastWrite = 0;
this.mousePressed = false;
this.mouseX = null;
this.mouseY = null;
},
write: function(address, value) {
if (address < 0x2000) {
// Mirroring of RAM:
this.nes.cpu.mem[address & 0x7FF] = value;
}
else if (address > 0x4017) {
this.nes.cpu.mem[address] = value;
if (address >= 0x6000 && address < 0x8000) {
// Write to SaveRAM. Store in file:
// TODO: not yet
//if(this.nes.rom!=null)
// this.nes.rom.writeBatteryRam(address,value);
}
}
else if (address > 0x2007 && address < 0x4000) {
this.regWrite(0x2000 + (address & 0x7), value);
}
else {
this.regWrite(address, value);
}
},
writelow: function(address, value) {
if (address < 0x2000) {
// Mirroring of RAM:
this.nes.cpu.mem[address & 0x7FF] = value;
}
else if (address > 0x4017) {
this.nes.cpu.mem[address] = value;
}
else if (address > 0x2007 && address < 0x4000) {
this.regWrite(0x2000 + (address & 0x7), value);
}
else {
this.regWrite(address, value);
}
},
load: function(address) {
// Wrap around:
address &= 0xFFFF;
// Check address range:
if (address > 0x4017) {
// ROM:
return this.nes.cpu.mem[address];
}
else if (address >= 0x2000) {
// I/O Ports.
return this.regLoad(address);
}
else {
// RAM (mirrored)
return this.nes.cpu.mem[address & 0x7FF];
}
},
regLoad: function(address) {
switch (address >> 12) { // use fourth nibble (0xF000)
case 0:
break;
case 1:
break;
case 2:
// Fall through to case 3
case 3:
// PPU Registers
switch (address & 0x7) {
case 0x0:
// 0x2000:
// PPU Control Register 1.
// (the value is stored both
// in main memory and in the
// PPU as flags):
// (not in the real NES)
return this.nes.cpu.mem[0x2000];
case 0x1:
// 0x2001:
// PPU Control Register 2.
// (the value is stored both
// in main memory and in the
// PPU as flags):
// (not in the real NES)
return this.nes.cpu.mem[0x2001];
case 0x2:
// 0x2002:
// PPU Status Register.
// The value is stored in
// main memory in addition
// to as flags in the PPU.
// (not in the real NES)
return this.nes.ppu.readStatusRegister();
case 0x3:
return 0;
case 0x4:
// 0x2004:
// Sprite Memory read.
return this.nes.ppu.sramLoad();
case 0x5:
return 0;
case 0x6:
return 0;
case 0x7:
// 0x2007:
// VRAM read:
return this.nes.ppu.vramLoad();
}
break;
case 4:
// Sound+Joypad registers
switch (address - 0x4015) {
case 0:
// 0x4015:
// Sound channel enable, DMC Status
return this.nes.papu.readReg(address);
case 1:
// 0x4016:
// Joystick 1 + Strobe
return this.joy1Read();
case 2:
// 0x4017:
// Joystick 2 + Strobe
if (this.mousePressed) {
// Check for white pixel nearby:
var sx = Math.max(0, this.mouseX - 4);
var ex = Math.min(256, this.mouseX + 4);
var sy = Math.max(0, this.mouseY - 4);
var ey = Math.min(240, this.mouseY + 4);
var w = 0;
for (var y=sy; y<ey; y++) {
for (var x=sx; x<ex; x++) {
if (this.nes.ppu.buffer[(y<<8)+x] == 0xFFFFFF) {
w |= 0x1<<3;
console.debug("Clicked on white!");
break;
}
}
}
w |= (this.mousePressed?(0x1<<4):0);
return (this.joy2Read()|w) & 0xFFFF;
}
else {
return this.joy2Read();
}
}
break;
}
return 0;
},
regWrite: function(address, value) {
switch (address) {
case 0x2000:
// PPU Control register 1
this.nes.cpu.mem[address] = value;
this.nes.ppu.updateControlReg1(value);
break;
case 0x2001:
// PPU Control register 2
this.nes.cpu.mem[address] = value;
this.nes.ppu.updateControlReg2(value);
break;
case 0x2003:
// Set Sprite RAM address:
this.nes.ppu.writeSRAMAddress(value);
break;
case 0x2004:
// Write to Sprite RAM:
this.nes.ppu.sramWrite(value);
break;
case 0x2005:
// Screen Scroll offsets:
this.nes.ppu.scrollWrite(value);
break;
case 0x2006:
// Set VRAM address:
this.nes.ppu.writeVRAMAddress(value);
break;
case 0x2007:
// Write to VRAM:
this.nes.ppu.vramWrite(value);
break;
case 0x4014:
// Sprite Memory DMA Access
this.nes.ppu.sramDMA(value);
break;
case 0x4015:
// Sound Channel Switch, DMC Status
this.nes.papu.writeReg(address, value);
break;
case 0x4016:
// Joystick 1 + Strobe
if ((value&1) === 0 && (this.joypadLastWrite&1) === 1) {
this.joy1StrobeState = 0;
this.joy2StrobeState = 0;
}
this.joypadLastWrite = value;
break;
case 0x4017:
// Sound channel frame sequencer:
this.nes.papu.writeReg(address, value);
break;
default:
// Sound registers
////System.out.println("write to sound reg");
if (address >= 0x4000 && address <= 0x4017) {
this.nes.papu.writeReg(address,value);
}
}
},
joy1Read: function() {
var ret;
switch (this.joy1StrobeState) {
case 0:
case 1:
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
ret = this.nes.keyboard.state1[this.joy1StrobeState];
break;
case 8:
case 9:
case 10:
case 11:
case 12:
case 13:
case 14:
case 15:
case 16:
case 17:
case 18:
ret = 0;
break;
case 19:
ret = 1;
break;
default:
ret = 0;
}
this.joy1StrobeState++;
if (this.joy1StrobeState == 24) {
this.joy1StrobeState = 0;
}
return ret;
},
joy2Read: function() {
var ret;
switch (this.joy2StrobeState) {
case 0:
case 1:
case 2:
case 3:
case 4:
case 5:
case 6:
case 7:
ret = this.nes.keyboard.state2[this.joy2StrobeState];
break;
case 8:
case 9:
case 10:
case 11:
case 12:
case 13:
case 14:
case 15:
case 16:
case 17:
case 18:
ret = 0;
break;
case 19:
ret = 1;
break;
default:
ret = 0;
}
this.joy2StrobeState++;
if (this.joy2StrobeState == 24) {
this.joy2StrobeState = 0;
}
return ret;
},
loadROM: function() {
if (!this.nes.rom.valid || this.nes.rom.romCount < 1) {
alert("NoMapper: Invalid ROM! Unable to load.");
return;
}
// Load ROM into memory:
this.loadPRGROM();
// Load CHR-ROM:
this.loadCHRROM();
// Load Battery RAM (if present):
this.loadBatteryRam();
// Reset IRQ:
//nes.getCpu().doResetInterrupt();
this.nes.cpu.requestIrq(this.nes.cpu.IRQ_RESET);
},
loadPRGROM: function() {
if (this.nes.rom.romCount > 1) {
// Load the two first banks into memory.
this.loadRomBank(0, 0x8000);
this.loadRomBank(1, 0xC000);
}
else {
// Load the one bank into both memory locations:
this.loadRomBank(0, 0x8000);
this.loadRomBank(0, 0xC000);
}
},
loadCHRROM: function() {
////System.out.println("Loading CHR ROM..");
if (this.nes.rom.vromCount > 0) {
if (this.nes.rom.vromCount == 1) {
this.loadVromBank(0,0x0000);
this.loadVromBank(0,0x1000);
}
else {
this.loadVromBank(0,0x0000);
this.loadVromBank(1,0x1000);
}
}
else {
//System.out.println("There aren't any CHR-ROM banks..");
}
},
loadBatteryRam: function() {
if (this.nes.rom.batteryRam) {
var ram = this.nes.rom.batteryRam;
if (ram !== null && ram.length == 0x2000) {
// Load Battery RAM into memory:
JSNES.Utils.copyArrayElements(ram, 0, this.nes.cpu.mem, 0x6000, 0x2000);
}
}
},
loadRomBank: function(bank, address) {
// Loads a ROM bank into the specified address.
bank %= this.nes.rom.romCount;
//var data = this.nes.rom.rom[bank];
//cpuMem.write(address,data,data.length);
JSNES.Utils.copyArrayElements(this.nes.rom.rom[bank], 0, this.nes.cpu.mem, address, 16384);
},
loadVromBank: function(bank, address) {
if (this.nes.rom.vromCount === 0) {
return;
}
this.nes.ppu.triggerRendering();
JSNES.Utils.copyArrayElements(this.nes.rom.vrom[bank % this.nes.rom.vromCount],
0, this.nes.ppu.vramMem, address, 4096);
var vromTile = this.nes.rom.vromTile[bank % this.nes.rom.vromCount];
JSNES.Utils.copyArrayElements(vromTile, 0, this.nes.ppu.ptTile,address >> 4, 256);
},
load32kRomBank: function(bank, address) {
this.loadRomBank((bank*2) % this.nes.rom.romCount, address);
this.loadRomBank((bank*2+1) % this.nes.rom.romCount, address+16384);
},
load8kVromBank: function(bank4kStart, address) {
if (this.nes.rom.vromCount === 0) {
return;
}
this.nes.ppu.triggerRendering();
this.loadVromBank((bank4kStart) % this.nes.rom.vromCount, address);
this.loadVromBank((bank4kStart + 1) % this.nes.rom.vromCount,
address + 4096);
},
load1kVromBank: function(bank1k, address) {
if (this.nes.rom.vromCount === 0) {
return;
}
this.nes.ppu.triggerRendering();
var bank4k = Math.floor(bank1k / 4) % this.nes.rom.vromCount;
var bankoffset = (bank1k % 4) * 1024;
JSNES.Utils.copyArrayElements(this.nes.rom.vrom[bank4k], 0,
this.nes.ppu.vramMem, bankoffset, 1024);
// Update tiles:
var vromTile = this.nes.rom.vromTile[bank4k];
var baseIndex = address >> 4;
for (var i = 0; i < 64; i++) {
this.nes.ppu.ptTile[baseIndex+i] = vromTile[((bank1k%4) << 6) + i];
}
},
load2kVromBank: function(bank2k, address) {
if (this.nes.rom.vromCount === 0) {
return;
}
this.nes.ppu.triggerRendering();
var bank4k = Math.floor(bank2k / 2) % this.nes.rom.vromCount;
var bankoffset = (bank2k % 2) * 2048;
JSNES.Utils.copyArrayElements(this.nes.rom.vrom[bank4k], bankoffset,
this.nes.ppu.vramMem, address, 2048);
// Update tiles:
var vromTile = this.nes.rom.vromTile[bank4k];
var baseIndex = address >> 4;
for (var i = 0; i < 128; i++) {
this.nes.ppu.ptTile[baseIndex+i] = vromTile[((bank2k%2) << 7) + i];
}
},
load8kRomBank: function(bank8k, address) {
var bank16k = Math.floor(bank8k / 2) % this.nes.rom.romCount;
var offset = (bank8k % 2) * 8192;
//this.nes.cpu.mem.write(address,this.nes.rom.rom[bank16k],offset,8192);
JSNES.Utils.copyArrayElements(this.nes.rom.rom[bank16k], offset,
this.nes.cpu.mem, address, 8192);
},
clockIrqCounter: function() {
// Does nothing. This is used by the MMC3 mapper.
},
latchAccess: function(address) {
// Does nothing. This is used by MMC2.
},
toJSON: function() {
return {
'joy1StrobeState': this.joy1StrobeState,
'joy2StrobeState': this.joy2StrobeState,
'joypadLastWrite': this.joypadLastWrite
};
},
fromJSON: function(s) {
this.joy1StrobeState = s.joy1StrobeState;
this.joy2StrobeState = s.joy2StrobeState;
this.joypadLastWrite = s.joypadLastWrite;
}
};
JSNES.Mappers[1] = function(nes) {
this.nes = nes;
};
JSNES.Mappers[1].prototype = new JSNES.Mappers[0]();
JSNES.Mappers[1].prototype.reset = function() {
JSNES.Mappers[0].prototype.reset.apply(this);
// 5-bit buffer:
this.regBuffer = 0;
this.regBufferCounter = 0;
// Register 0:
this.mirroring = 0;
this.oneScreenMirroring = 0;
this.prgSwitchingArea = 1;
this.prgSwitchingSize = 1;
this.vromSwitchingSize = 0;
// Register 1:
this.romSelectionReg0 = 0;
// Register 2:
this.romSelectionReg1 = 0;
// Register 3:
this.romBankSelect = 0;
};
JSNES.Mappers[1].prototype.write = function(address, value) {
// Writes to addresses other than MMC registers are handled by NoMapper.
if (address < 0x8000) {
JSNES.Mappers[0].prototype.write.apply(this, arguments);
return;
}
// See what should be done with the written value:
if ((value & 128) !== 0) {
// Reset buffering:
this.regBufferCounter = 0;
this.regBuffer = 0;
// Reset register:
if (this.getRegNumber(address) === 0) {
this.prgSwitchingArea = 1;
this.prgSwitchingSize = 1;
}
}
else {
// Continue buffering:
//regBuffer = (regBuffer & (0xFF-(1<<regBufferCounter))) | ((value & (1<<regBufferCounter))<<regBufferCounter);
this.regBuffer = (this.regBuffer & (0xFF - (1 << this.regBufferCounter))) | ((value & 1) << this.regBufferCounter);
this.regBufferCounter++;
if (this.regBufferCounter == 5) {
// Use the buffered value:
this.setReg(this.getRegNumber(address), this.regBuffer);
// Reset buffer:
this.regBuffer = 0;
this.regBufferCounter = 0;
}
}
};
JSNES.Mappers[1].prototype.setReg = function(reg, value) {
var tmp;
switch (reg) {
case 0:
// Mirroring:
tmp = value & 3;
if (tmp !== this.mirroring) {
// Set mirroring:
this.mirroring = tmp;
if ((this.mirroring & 2) === 0) {
// SingleScreen mirroring overrides the other setting:
this.nes.ppu.setMirroring(
this.nes.rom.SINGLESCREEN_MIRRORING);
}
// Not overridden by SingleScreen mirroring.
else if ((this.mirroring & 1) !== 0) {
this.nes.ppu.setMirroring(
this.nes.rom.HORIZONTAL_MIRRORING
);
}
else {
this.nes.ppu.setMirroring(this.nes.rom.VERTICAL_MIRRORING);
}
}
// PRG Switching Area;
this.prgSwitchingArea = (value >> 2) & 1;
// PRG Switching Size:
this.prgSwitchingSize = (value >> 3) & 1;
// VROM Switching Size:
this.vromSwitchingSize = (value >> 4) & 1;
break;
case 1:
// ROM selection:
this.romSelectionReg0 = (value >> 4) & 1;
// Check whether the cart has VROM:
if (this.nes.rom.vromCount > 0) {
// Select VROM bank at 0x0000:
if (this.vromSwitchingSize === 0) {
// Swap 8kB VROM:
if (this.romSelectionReg0 === 0) {
this.load8kVromBank((value & 0xF), 0x0000);
}
else {
this.load8kVromBank(
Math.floor(this.nes.rom.vromCount / 2) +
(value & 0xF),
0x0000
);
}
}
else {
// Swap 4kB VROM:
if (this.romSelectionReg0 === 0) {
this.loadVromBank((value & 0xF), 0x0000);
}
else {
this.loadVromBank(
Math.floor(this.nes.rom.vromCount / 2) +
(value & 0xF),
0x0000
);
}
}
}
break;
case 2:
// ROM selection:
this.romSelectionReg1 = (value >> 4) & 1;
// Check whether the cart has VROM:
if (this.nes.rom.vromCount > 0) {
// Select VROM bank at 0x1000:
if (this.vromSwitchingSize === 1) {
// Swap 4kB of VROM:
if (this.romSelectionReg1 === 0) {
this.loadVromBank((value & 0xF), 0x1000);
}
else {
this.loadVromBank(
Math.floor(this.nes.rom.vromCount / 2) +
(value & 0xF),
0x1000
);
}
}
}
break;
default:
// Select ROM bank:
// -------------------------
tmp = value & 0xF;
var bank;
var baseBank = 0;
if (this.nes.rom.romCount >= 32) {
// 1024 kB cart
if (this.vromSwitchingSize === 0) {
if (this.romSelectionReg0 === 1) {
baseBank = 16;
}
}
else {
baseBank = (this.romSelectionReg0
| (this.romSelectionReg1 << 1)) << 3;
}
}
else if (this.nes.rom.romCount >= 16) {
// 512 kB cart
if (this.romSelectionReg0 === 1) {
baseBank = 8;
}
}
if (this.prgSwitchingSize === 0) {
// 32kB
bank = baseBank + (value & 0xF);
this.load32kRomBank(bank, 0x8000);
}
else {
// 16kB
bank = baseBank * 2 + (value & 0xF);
if (this.prgSwitchingArea === 0) {
this.loadRomBank(bank, 0xC000);
}
else {
this.loadRomBank(bank, 0x8000);
}
}
}
};
// Returns the register number from the address written to:
JSNES.Mappers[1].prototype.getRegNumber = function(address) {
if (address >= 0x8000 && address <= 0x9FFF) {
return 0;
}
else if (address >= 0xA000 && address <= 0xBFFF) {
return 1;
}
else if (address >= 0xC000 && address <= 0xDFFF) {
return 2;
}
else {
return 3;
}
};
JSNES.Mappers[1].prototype.loadROM = function(rom) {
if (!this.nes.rom.valid) {
alert("MMC1: Invalid ROM! Unable to load.");
return;
}
// Load PRG-ROM:
this.loadRomBank(0, 0x8000); // First ROM bank..
this.loadRomBank(this.nes.rom.romCount - 1, 0xC000); // ..and last ROM bank.
// Load CHR-ROM:
this.loadCHRROM();
// Load Battery RAM (if present):
this.loadBatteryRam();
// Do Reset-Interrupt:
this.nes.cpu.requestIrq(this.nes.cpu.IRQ_RESET);
};
JSNES.Mappers[1].prototype.switchLowHighPrgRom = function(oldSetting) {
// not yet.
};
JSNES.Mappers[1].prototype.switch16to32 = function() {
// not yet.
};
JSNES.Mappers[1].prototype.switch32to16 = function() {
// not yet.
};
JSNES.Mappers[1].prototype.toJSON = function() {
var s = JSNES.Mappers[0].prototype.toJSON.apply(this);
s.mirroring = this.mirroring;
s.oneScreenMirroring = this.oneScreenMirroring;
s.prgSwitchingArea = this.prgSwitchingArea;
s.prgSwitchingSize = this.prgSwitchingSize;
s.vromSwitchingSize = this.vromSwitchingSize;
s.romSelectionReg0 = this.romSelectionReg0;
s.romSelectionReg1 = this.romSelectionReg1;
s.romBankSelect = this.romBankSelect;
s.regBuffer = this.regBuffer;
s.regBufferCounter = this.regBufferCounter;
return s;
};
JSNES.Mappers[1].prototype.fromJSON = function(s) {
JSNES.Mappers[0].prototype.fromJSON.apply(this, s);
this.mirroring = s.mirroring;
this.oneScreenMirroring = s.oneScreenMirroring;
this.prgSwitchingArea = s.prgSwitchingArea;
this.prgSwitchingSize = s.prgSwitchingSize;
this.vromSwitchingSize = s.vromSwitchingSize;
this.romSelectionReg0 = s.romSelectionReg0;
this.romSelectionReg1 = s.romSelectionReg1;
this.romBankSelect = s.romBankSelect;
this.regBuffer = s.regBuffer;
this.regBufferCounter = s.regBufferCounter;
};
JSNES.Mappers[2] = function(nes) {
this.nes = nes;
};
JSNES.Mappers[2].prototype = new JSNES.Mappers[0]();
JSNES.Mappers[2].prototype.write = function(address, value) {
// Writes to addresses other than MMC registers are handled by NoMapper.
if (address < 0x8000) {
JSNES.Mappers[0].prototype.write.apply(this, arguments);
return;
}
else {
// This is a ROM bank select command.
// Swap in the given ROM bank at 0x8000:
this.loadRomBank(value, 0x8000);
}
};
JSNES.Mappers[2].prototype.loadROM = function(rom) {
if (!this.nes.rom.valid) {
alert("UNROM: Invalid ROM! Unable to load.");
return;
}
// Load PRG-ROM:
this.loadRomBank(0, 0x8000);
this.loadRomBank(this.nes.rom.romCount - 1, 0xC000);
// Load CHR-ROM:
this.loadCHRROM();
// Do Reset-Interrupt:
this.nes.cpu.requestIrq(this.nes.cpu.IRQ_RESET);
};
JSNES.Mappers[4] = function(nes) {
this.nes = nes;
this.CMD_SEL_2_1K_VROM_0000 = 0;
this.CMD_SEL_2_1K_VROM_0800 = 1;
this.CMD_SEL_1K_VROM_1000 = 2;
this.CMD_SEL_1K_VROM_1400 = 3;
this.CMD_SEL_1K_VROM_1800 = 4;
this.CMD_SEL_1K_VROM_1C00 = 5;
this.CMD_SEL_ROM_PAGE1 = 6;
this.CMD_SEL_ROM_PAGE2 = 7;
this.command = null;
this.prgAddressSelect = null;
this.chrAddressSelect = null;
this.pageNumber = null;
this.irqCounter = null;
this.irqLatchValue = null;
this.irqEnable = null;
this.prgAddressChanged = false;
};
JSNES.Mappers[4].prototype = new JSNES.Mappers[0]();
JSNES.Mappers[4].prototype.write = function(address, value) {
// Writes to addresses other than MMC registers are handled by NoMapper.
if (address < 0x8000) {
JSNES.Mappers[0].prototype.write.apply(this, arguments);
return;
}
switch (address) {
case 0x8000:
// Command/Address Select register
this.command = value & 7;
var tmp = (value >> 6) & 1;
if (tmp != this.prgAddressSelect) {
this.prgAddressChanged = true;
}
this.prgAddressSelect = tmp;
this.chrAddressSelect = (value >> 7) & 1;
break;
case 0x8001:
// Page number for command
this.executeCommand(this.command, value);
break;
case 0xA000:
// Mirroring select
if ((value & 1) !== 0) {
this.nes.ppu.setMirroring(
this.nes.rom.HORIZONTAL_MIRRORING
);
}
else {
this.nes.ppu.setMirroring(this.nes.rom.VERTICAL_MIRRORING);
}
break;
case 0xA001:
// SaveRAM Toggle
// TODO
//nes.getRom().setSaveState((value&1)!=0);
break;
case 0xC000:
// IRQ Counter register
this.irqCounter = value;
//nes.ppu.mapperIrqCounter = 0;
break;
case 0xC001:
// IRQ Latch register
this.irqLatchValue = value;
break;
case 0xE000:
// IRQ Control Reg 0 (disable)
//irqCounter = irqLatchValue;
this.irqEnable = 0;
break;
case 0xE001:
// IRQ Control Reg 1 (enable)
this.irqEnable = 1;
break;
default:
// Not a MMC3 register.
// The game has probably crashed,
// since it tries to write to ROM..
// IGNORE.
}
};
JSNES.Mappers[4].prototype.executeCommand = function(cmd, arg) {
switch (cmd) {
case this.CMD_SEL_2_1K_VROM_0000:
// Select 2 1KB VROM pages at 0x0000:
if (this.chrAddressSelect === 0) {
this.load1kVromBank(arg, 0x0000);
this.load1kVromBank(arg + 1, 0x0400);
}
else {
this.load1kVromBank(arg, 0x1000);
this.load1kVromBank(arg + 1, 0x1400);
}
break;
case this.CMD_SEL_2_1K_VROM_0800:
// Select 2 1KB VROM pages at 0x0800:
if (this.chrAddressSelect === 0) {
this.load1kVromBank(arg, 0x0800);
this.load1kVromBank(arg + 1, 0x0C00);
}
else {
this.load1kVromBank(arg, 0x1800);
this.load1kVromBank(arg + 1, 0x1C00);
}
break;
case this.CMD_SEL_1K_VROM_1000:
// Select 1K VROM Page at 0x1000:
if (this.chrAddressSelect === 0) {
this.load1kVromBank(arg, 0x1000);
}
else {
this.load1kVromBank(arg, 0x0000);
}
break;
case this.CMD_SEL_1K_VROM_1400:
// Select 1K VROM Page at 0x1400:
if (this.chrAddressSelect === 0) {
this.load1kVromBank(arg, 0x1400);
}
else {
this.load1kVromBank(arg, 0x0400);
}
break;
case this.CMD_SEL_1K_VROM_1800:
// Select 1K VROM Page at 0x1800: