diff options
Diffstat (limited to 'source/rom.js')
| -rw-r--r-- | source/rom.js | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/source/rom.js b/source/rom.js new file mode 100644 index 0000000..928873f --- /dev/null +++ b/source/rom.js @@ -0,0 +1,215 @@ +/* +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.ROM = function(nes) { + this.nes = nes; + + this.mapperName = new Array(92); + + for (var i=0;i<92;i++) { + this.mapperName[i] = "Unknown Mapper"; + } + this.mapperName[ 0] = "Direct Access"; + this.mapperName[ 1] = "Nintendo MMC1"; + this.mapperName[ 2] = "UNROM"; + this.mapperName[ 3] = "CNROM"; + this.mapperName[ 4] = "Nintendo MMC3"; + this.mapperName[ 5] = "Nintendo MMC5"; + this.mapperName[ 6] = "FFE F4xxx"; + this.mapperName[ 7] = "AOROM"; + this.mapperName[ 8] = "FFE F3xxx"; + this.mapperName[ 9] = "Nintendo MMC2"; + this.mapperName[10] = "Nintendo MMC4"; + this.mapperName[11] = "Color Dreams Chip"; + this.mapperName[12] = "FFE F6xxx"; + this.mapperName[15] = "100-in-1 switch"; + this.mapperName[16] = "Bandai chip"; + this.mapperName[17] = "FFE F8xxx"; + this.mapperName[18] = "Jaleco SS8806 chip"; + this.mapperName[19] = "Namcot 106 chip"; + this.mapperName[20] = "Famicom Disk System"; + this.mapperName[21] = "Konami VRC4a"; + this.mapperName[22] = "Konami VRC2a"; + this.mapperName[23] = "Konami VRC2a"; + this.mapperName[24] = "Konami VRC6"; + this.mapperName[25] = "Konami VRC4b"; + this.mapperName[32] = "Irem G-101 chip"; + this.mapperName[33] = "Taito TC0190/TC0350"; + this.mapperName[34] = "32kB ROM switch"; + + this.mapperName[64] = "Tengen RAMBO-1 chip"; + this.mapperName[65] = "Irem H-3001 chip"; + this.mapperName[66] = "GNROM switch"; + this.mapperName[67] = "SunSoft3 chip"; + this.mapperName[68] = "SunSoft4 chip"; + this.mapperName[69] = "SunSoft5 FME-7 chip"; + this.mapperName[71] = "Camerica chip"; + this.mapperName[78] = "Irem 74HC161/32-based"; + this.mapperName[91] = "Pirate HK-SF3 chip"; +}; + +JSNES.ROM.prototype = { + // Mirroring types: + VERTICAL_MIRRORING: 0, + HORIZONTAL_MIRRORING: 1, + FOURSCREEN_MIRRORING: 2, + SINGLESCREEN_MIRRORING: 3, + SINGLESCREEN_MIRRORING2: 4, + SINGLESCREEN_MIRRORING3: 5, + SINGLESCREEN_MIRRORING4: 6, + CHRROM_MIRRORING: 7, + + header: null, + rom: null, + vrom: null, + vromTile: null, + + romCount: null, + vromCount: null, + mirroring: null, + batteryRam: null, + trainer: null, + fourScreen: null, + mapperType: null, + valid: false, + + load: function(data) { + var i, j, v; + + if (data.indexOf("NES\x1a") === -1) { + this.nes.ui.updateStatus("Not a valid NES ROM."); + return; + } + this.header = new Array(16); + for (i = 0; i < 16; i++) { + this.header[i] = data.charCodeAt(i) & 0xFF; + } + this.romCount = this.header[4]; + this.vromCount = this.header[5]*2; // Get the number of 4kB banks, not 8kB + this.mirroring = ((this.header[6] & 1) !== 0 ? 1 : 0); + this.batteryRam = (this.header[6] & 2) !== 0; + this.trainer = (this.header[6] & 4) !== 0; + this.fourScreen = (this.header[6] & 8) !== 0; + this.mapperType = (this.header[6] >> 4) | (this.header[7] & 0xF0); + /* TODO + if (this.batteryRam) + this.loadBatteryRam();*/ + // Check whether byte 8-15 are zero's: + var foundError = false; + for (i=8; i<16; i++) { + if (this.header[i] !== 0) { + foundError = true; + break; + } + } + if (foundError) { + this.mapperType &= 0xF; // Ignore byte 7 + } + // Load PRG-ROM banks: + this.rom = new Array(this.romCount); + var offset = 16; + for (i=0; i < this.romCount; i++) { + this.rom[i] = new Array(16384); + for (j=0; j < 16384; j++) { + if (offset+j >= data.length) { + break; + } + this.rom[i][j] = data.charCodeAt(offset + j) & 0xFF; + } + offset += 16384; + } + // Load CHR-ROM banks: + this.vrom = new Array(this.vromCount); + for (i=0; i < this.vromCount; i++) { + this.vrom[i] = new Array(4096); + for (j=0; j < 4096; j++) { + if (offset+j >= data.length){ + break; + } + this.vrom[i][j] = data.charCodeAt(offset + j) & 0xFF; + } + offset += 4096; + } + + // Create VROM tiles: + this.vromTile = new Array(this.vromCount); + for (i=0; i < this.vromCount; i++) { + this.vromTile[i] = new Array(256); + for (j=0; j < 256; j++) { + this.vromTile[i][j] = new JSNES.PPU.Tile(); + } + } + + // Convert CHR-ROM banks to tiles: + var tileIndex; + var leftOver; + for (v=0; v < this.vromCount; v++) { + for (i=0; i < 4096; i++) { + tileIndex = i >> 4; + leftOver = i % 16; + if (leftOver < 8) { + this.vromTile[v][tileIndex].setScanline( + leftOver, + this.vrom[v][i], + this.vrom[v][i+8] + ); + } + else { + this.vromTile[v][tileIndex].setScanline( + leftOver-8, + this.vrom[v][i-8], + this.vrom[v][i] + ); + } + } + } + + this.valid = true; + }, + + getMirroringType: function() { + if (this.fourScreen) { + return this.FOURSCREEN_MIRRORING; + } + if (this.mirroring === 0) { + return this.HORIZONTAL_MIRRORING; + } + return this.VERTICAL_MIRRORING; + }, + + getMapperName: function() { + if (this.mapperType >= 0 && this.mapperType < this.mapperName.length) { + return this.mapperName[this.mapperType]; + } + return "Unknown Mapper, "+this.mapperType; + }, + + mapperSupported: function() { + return typeof JSNES.Mappers[this.mapperType] !== 'undefined'; + }, + + createMapper: function() { + if (this.mapperSupported()) { + return new JSNES.Mappers[this.mapperType](this.nes); + } + else { + this.nes.ui.updateStatus("This ROM uses a mapper not supported by JSNES: "+this.getMapperName()+"("+this.mapperType+")"); + return null; + } + } +}; |