mirror of
https://github.com/felipecsl/6502Android.git
synced 2024-06-07 15:48:23 +00:00
Making progress on PPU implementation
This commit is contained in:
parent
9a9ad49aa3
commit
143bd655c6
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@ -109,7 +109,7 @@ class CPU(val memory: Memory) : Display.Callbacks {
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target.method.invoke()
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} else {
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val candidate = Opcodes.MAP.entries
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.first { it.value.any { it.opcode == instruction } }
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.first { e -> e.value.any { it.opcode == instruction } }
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throw Exception(
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"Address $${PC.toHexString()} - unknown opcode 0x${instruction.toHexString()} " +
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"(instruction ${candidate.key.name})")
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@ -0,0 +1,9 @@
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package android.emu6502
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infix fun Byte.shr(other: Int): Byte {
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return this.toInt().shr(other).toByte()
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}
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infix fun Byte.shl(other: Int): Byte {
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return this.toInt().shr(other).toByte()
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}
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@ -1,5 +1,13 @@
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package android.emu6502.nes
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class Controller {
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var buttons: Array<Boolean> = Array(8) { false }
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var index: Byte = 0
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var strobe: Byte = 0
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fun read() {
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}
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fun write() {
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}
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}
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@ -8,7 +8,6 @@ import java.util.*
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// Sample header:
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// 4e 45 53 1a 10 10 40 00 00 00 00 00 00 00 00 00
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data class INESFileHeader(
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// @formatter:off
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val magic: ByteArray, // Constant $4E $45 $53 $1A ("NES" followed by MS-DOS end-of-file)
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val numPRG: Byte, // Size of PRG ROM in 16 KB units
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val numCHR: Byte, // Size of CHR ROM in 8 KB units (Value 0 means the board uses CHR RAM)
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@ -16,7 +15,6 @@ data class INESFileHeader(
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val control2: Byte, // Flags 7
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val numRAM: Byte, // Size of PRG RAM in 8 KB units
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val padding: ByteArray // 7 bytes, unused
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// @formatter:on
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) {
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fun isValid() =
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Arrays.equals(magic, INES_FILE_MAGIC) && Arrays.equals(padding, PADDING)
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@ -21,30 +21,31 @@ internal class INESFileParser {
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(0..6).map { dataStream.readByte() }.toByteArray())
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}
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internal fun parseCartridge(file: File): Cartridge {
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val stream = file.inputStream()
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stream.use {
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val inesFileHeader = parseFileHeader(stream)
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// mapper type
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val control1 = inesFileHeader.control1.toInt()
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val mapper1 = control1 shr 4
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val mapper2 = inesFileHeader.control2.toInt() shr 4
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val mapper = mapper1 or (mapper2 shl 4)
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// mirroring type
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val mirror1 = control1 and 1
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val mirror2 = (control1 shr 3) and 1
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val mirror = mirror1 or (mirror2 shl 1)
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// battery-backed RAM
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val battery = control1.shr(1).and(1).toByte()
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// read prg-rom bank(s)
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val pgr = ByteArray(inesFileHeader.numPRG.toInt() * 16384)
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stream.read(pgr)
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// read chr-rom bank(s)
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val chr = ByteArray(inesFileHeader.numCHR.toInt() * 8192)
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stream.read(chr)
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return Cartridge(pgr.map(Byte::toInt).toIntArray(), chr.map(Byte::toInt).toIntArray(),
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mapper.toByte(), mirror, battery)
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}
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}
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internal fun parseCartridge(file: File): Cartridge =
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file.inputStream().use {
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val inesFileHeader = parseFileHeader(it)
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// mapper type
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val control1 = inesFileHeader.control1.toInt()
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val mapper1 = control1 shr 4
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val mapper2 = inesFileHeader.control2.toInt() shr 4
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val mapper = mapper1 or (mapper2 shl 4)
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// mirroring type
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val mirror1 = control1 and 1
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val mirror2 = (control1 shr 3) and 1
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val mirror = mirror1 or (mirror2 shl 1)
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// battery-backed RAM
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val battery = (control1 shr 1).and(1).toByte()
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// read prg-rom bank(s)
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val prg = ByteArray(inesFileHeader.numPRG.toInt() * 16384)
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it.read(prg)
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// read chr-rom bank(s)
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val chr = ByteArray(inesFileHeader.numCHR.toInt() * 8192)
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it.read(chr)
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return Cartridge(
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prg.map(Byte::toInt).toIntArray(),
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chr.map(Byte::toInt).toIntArray(),
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mapper.toByte(), mirror, battery
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)
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}
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}
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}
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@ -1,47 +1,211 @@
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package android.emu6502.nes
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import android.emu6502.shl
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import android.emu6502.shr
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import android.media.Image
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import android.system.Os.read
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import kotlin.experimental.and
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import kotlin.experimental.xor
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class PPU(
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val console: Console,
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// @formatter:off
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val cycle: Int = 0, // 0-340
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val scanLine: Int = 0, // 0-261, 0-239=visible, 240=post, 241-260=vblank, 261=pre
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val frame: Int = 0, // frame counter
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var cycle: Int = 0, // 0-340
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var scanLine: Int = 0, // 0-261, 0-239=visible, 240=post, 241-260=vblank, 261=pre
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var frame: Int = 0, // frame counter
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// storage variables
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var paletteData: ByteArray = ByteArray(32),
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var nameTableData: ByteArray = ByteArray(2048),
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var oamData: ByteArray = ByteArray(256),
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var front: Image,
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var back: Image,
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// PPU registers
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val v: Int = 0, // current vram address (15 bit)
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val t: Int = 0, // temporary vram address (15 bit)
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val x: Byte = 0, // fine x scroll (3 bit)
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val w: Byte = 0, // write toggle (1 bit)
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val f: Byte = 0, // even/odd frame flag (1 bit)
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val register: Byte = 0,
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var v: Int = 0, // current vram address (15 bit)
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var t: Int = 0, // temporary vram address (15 bit)
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var x: Byte = 0, // fine x scroll (3 bit)
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var w: Byte = 0, // write toggle (1 bit)
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var f: Byte = 0, // even/odd frame flag (1 bit)
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var register: Byte = 0,
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var nmiOccurred: Boolean = false,
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var nmiOutput: Boolean = false,
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var nmiPrevious: Boolean = false,
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var nmiDelay: Byte = 0,
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// background temporary variables
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var nameTableByte: Byte = 0,
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var attributeTableByte: Byte = 0,
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var lowTileByte: Byte = 0,
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var highTileByte: Byte = 0,
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var tileData: Int = 0,
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// $2000 PPUCTRL
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val flagNameTable: Boolean = false, // 0: $2000; 1: $2400; 2: $2800; 3: $2C00
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val flagIncrement: Boolean = false, // 0: add 1; 1: add 32
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val flagSpriteTable: Boolean = false, // 0: $0000; 1: $1000; ignored in 8x16 mode
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val flagBackgroundTable: Boolean = false, // 0: $0000; 1: $1000
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val flagSpriteSize: Boolean = false, // 0: 8x8; 1: 8x16
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val flagMasterSlave: Boolean = false, // 0: read EXT; 1: write EXT
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var flagNameTable: Byte = 0, // 0: $2000; 1: $2400; 2: $2800; 3: $2C00
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var flagIncrement: Byte = 0, // 0: add 1; 1: add 32
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var flagSpriteTable: Byte = 0, // 0: $0000; 1: $1000; ignored in 8x16 mode
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var flagBackgroundTable: Byte = 0, // 0: $0000; 1: $1000
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var flagSpriteSize: Byte = 0, // 0: 8x8; 1: 8x16
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var flagMasterSlave: Byte = 0, // 0: read EXT; 1: write EXT
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// $2001 PPUMASK
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val flagGrayscale: Boolean = false, // 0: color; 1: grayscale
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val flagShowLeftBackground: Boolean = false, // 0: hide; 1: show
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val flagShowLeftSprites: Boolean = false, // 0: hide; 1: show
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val flagShowBackground: Boolean = false, // 0: hide; 1: show
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val flagShowSprites: Boolean = false, // 0: hide; 1: show
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val flagRedTint: Boolean = false, // 0: normal; 1: emphasized
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val flagGreenTint: Boolean = false, // 0: normal; 1: emphasized
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val flagBlueTint: Boolean = false, // 0: normal; 1: emphasized
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var flagGrayscale: Byte = 0, // 0: color; 1: grayscale
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var flagShowLeftBackground: Byte = 0, // 0: hide; 1: show
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var flagShowLeftSprites: Byte = 0, // 0: hide; 1: show
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var flagShowBackground: Byte = 0, // 0: hide; 1: show
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var flagShowSprites: Byte = 0, // 0: hide; 1: show
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var flagRedTint: Byte = 0, // 0: normal; 1: emphasized
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var flagGreenTint: Byte = 0, // 0: normal; 1: emphasized
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var flagBlueTint: Byte = 0, // 0: normal; 1: emphasized
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// $2002 PPUSTATUS
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val flagSpriteZeroHit: Boolean = false,
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val flagSpriteOverflow: Boolean = false,
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// $2003 OAMADDR
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val oamAddress: Byte = 0,
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var oamAddress: Byte = 0,
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// $2007 PPUDATA
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val bufferedData: Byte = 0 // for buffered reads
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// @formatter:on
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)
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) {
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fun writeRegister(address: Int, value: Byte) {
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register = value
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when (address) {
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0x2000 -> writeControl(value)
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0x2001 -> writeMask(value)
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0x2003 -> writeOAMAddress(value)
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0x2004 -> writeOAMData(value)
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0x2005 -> writeScroll(value)
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0x2006 -> writeAddress(value)
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0x2007 -> writeData(value)
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0x4014 -> writeDMA(value)
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}
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}
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private fun writeDMA(value: Byte) {
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TODO()
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}
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private fun step() {
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tick()
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val renderingEnabled = flagShowBackground != 0.toByte() || flagShowSprites != 0.toByte()
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val preLine = scanLine == 261
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val visibleLine = scanLine < 240
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// postLine = scanLine == 240
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val renderLine = preLine || visibleLine
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val preFetchCycle = cycle in 321..336
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val visibleCycle = cycle in 1..256
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val fetchCycle = preFetchCycle || visibleCycle
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}
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private fun tick() {
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if (nmiDelay > 0) {
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nmiDelay--
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if (nmiDelay == 0.toByte() && nmiOutput && nmiOccurred) {
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console.cpu.triggerNMI()
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}
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}
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if (flagShowBackground != 0.toByte() || flagShowSprites != 0.toByte()) {
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if (f == 1.toByte() && scanLine == 261 && cycle == 339) {
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cycle = 0
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scanLine = 0
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frame++
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f = f xor 1
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return
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}
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}
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cycle++
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if (cycle > 340) {
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cycle = 0
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scanLine++
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if (scanLine > 261) {
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scanLine = 0
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frame++
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f = f xor 1
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}
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}
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}
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private fun writeData(value: Byte) {
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TODO("not implemented")
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}
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// $2006: PPUADDR
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private fun writeAddress(value: Byte) {
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if (w == 0.toByte()) {
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// t: ..FEDCBA ........ = d: ..FEDCBA
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// t: .X...... ........ = 0
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// w: = 1
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t = (t and 0x80FF) or ((value and 0x3F) shl 8).toInt()
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w = 1
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} else {
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// t: ........ HGFEDCBA = d: HGFEDCBA
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// v = t
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// w: = 0
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t = (t and 0xFF00) or value.toInt()
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v = t
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w = 0
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}
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}
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// $2005: PPUSCROLL
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private fun writeScroll(value: Byte) {
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TODO("not implemented")
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}
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// $2004: OAMDATA (write)
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private fun writeOAMData(value: Byte) {
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oamData[oamAddress.toInt()] = value
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oamAddress++
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}
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// $2003: OAMADDR
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private fun writeOAMAddress(value: Byte) {
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oamAddress = value
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}
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private fun writeMask(value: Byte) {
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flagGrayscale = (value shr 0) and 1
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flagShowLeftBackground = (value shr 1) and 1
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flagShowLeftSprites = (value shr 2) and 1
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flagShowBackground = (value shr 3) and 1
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flagShowSprites = (value shr 4) and 1
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flagRedTint = (value shr 5) and 1
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flagGreenTint = (value shr 6) and 1
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flagBlueTint = (value shr 7) and 1
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}
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// $2000: PPUCTRL
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private fun writeControl(value: Byte) {
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flagNameTable = (value shr 0) and 3
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flagIncrement = (value shr 2) and 1
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flagSpriteTable = (value shr 3) and 1
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flagBackgroundTable = (value shr 4) and 1
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flagSpriteSize = (value shr 5) and 1
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flagMasterSlave = (value shr 6) and 1
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nmiOutput = (value shr 7) and 1 == 1.toByte()
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nmiChange()
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// t: ....BA.. ........ = d: ......BA
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t = (t and 0xF3FF) or ((value and 0x03) shl 10).toInt()
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}
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private fun nmiChange() {
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val nmi = nmiOutput && nmiOccurred
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if (nmi && !nmiPrevious) {
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// TODO: this fixes some games but the delay shouldn't have to be so
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// long, so the timings are off somewhere
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nmiDelay = 15
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}
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nmiPrevious = nmi
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}
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private fun fetchNameTableByte() {
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val address = 0x2000 or (v and 0x0FFF)
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nameTableByte = read(address)
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}
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}
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@ -22,34 +22,39 @@ class MMC3(
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private var irqEnable: Boolean = false
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override fun read(address: Int): Int {
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if (address < 0x2000) {
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val bank = address / 0x0400
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val offset = address % 0x0400
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return cartridge.chr[chrOffsets[bank] + offset]
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return when {
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address < 0x2000 -> {
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val bank = address / 0x0400
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val offset = address % 0x0400
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cartridge.chr[chrOffsets[bank] + offset]
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}
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address >= 0x8000 -> {
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val addr = address - 0x8000
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val bank = addr / 0x2000
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val offset = addr % 0x2000
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cartridge.pgr[prgOffsets[bank] + offset]
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}
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address >= 0x6000 -> {
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return cartridge.sram[address - 0x6000]
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}
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else -> throw RuntimeException("unhandled mapper4 read at address: ${address.toHexString()}")
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}
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if (address >= 0x8000) {
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val addr = address - 0x8000
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val bank = addr / 0x2000
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val offset = addr % 0x2000
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return cartridge.pgr[prgOffsets[bank] + offset]
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}
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if (address >= 0x6000) {
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return cartridge.sram[address - 0x6000]
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}
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throw RuntimeException("unhandled mapper4 read at address: ${address.toHexString()}")
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}
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override fun write(address: Int, value: Int) {
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if (address < 0x2000) {
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val bank = address / 0x0400
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val offset = address % 0x0400
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cartridge.chr[chrOffsets[bank] + offset] = value
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} else if (address >= 0x8000) {
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writeRegister(address, value)
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} else if (address >= 0x6000) {
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cartridge.sram[address - 0x6000] = value
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} else {
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throw RuntimeException("unhandled mapper4 write at address ${address.toHexString()}")
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when {
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address < 0x2000 -> {
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val bank = address / 0x0400
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val offset = address % 0x0400
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cartridge.chr[chrOffsets[bank] + offset] = value
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}
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address >= 0x8000 -> {
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writeRegister(address, value)
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}
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address >= 0x6000 -> {
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cartridge.sram[address - 0x6000] = value
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}
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else -> throw RuntimeException("unhandled mapper4 write at address ${address.toHexString()}")
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}
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}
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@ -13,7 +13,7 @@ interface Mapper {
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fun newMapper(cartridge: Cartridge, ppu: PPU, cpu: CPU): Mapper =
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when (cartridge.mapper.toInt()) {
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4 -> MMC3(cartridge, ppu, cpu)
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else -> throw NotImplementedError()
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else -> throw NotImplementedError("Mapper ${cartridge.mapper.toInt()} not implemented")
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}
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}
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}
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