144 lines
3.0 KiB
C#
144 lines
3.0 KiB
C#
using BizHawk.Common;
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namespace BizHawk.Emulation.Cores.Nintendo.NES
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{
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public sealed class Mapper243 : NES.NESBoardBase
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{
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/*
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Here are Disch's original notes:
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========================
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= Mapper 243 =
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========================
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Example Games:
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--------------------------
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Honey
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Poker III 5-in-1
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Registers:
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---------------------------
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Range,Mask: $4020-4FFF, $4101
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$4100: [.... .AAA] Address for use with $4101
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$4101: Data port
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R:2 -> [.... ...H] High bit of CHR reg
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R:4 -> [.... ...L] Low bit of CHR reg
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R:5 -> [.... .PPP] PRG reg (32k @ $8000)
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R:6 -> [.... ..DD] Middle bits of CHR reg
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R:7 -> [.... .MM.] Mirroring
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%00 = Horz
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%01 = Vert
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%10 = See below
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%11 = 1ScB
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Mirroring:
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---------------------------
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Mirroing mode %10 is not quite 1ScB:
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[ NTA ][ NTB ]
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[ NTB ][ NTB ]
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CHR Setup:
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---------------------------
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8k CHR page @ $0000 is selected by the given 4 bit CHR page number ('HDDL')
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*/
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int reg_addr;
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ByteBuffer regs = new ByteBuffer(8);
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int chr_bank_mask_8k, prg_bank_mask_32k;
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public override bool Configure(NES.EDetectionOrigin origin)
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{
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switch (Cart.board_type)
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{
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case "MAPPER243":
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case "UNIF_UNL-Sachen-74LS374N": // seems to have some problems
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break;
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default:
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return false;
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}
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chr_bank_mask_8k = Cart.chr_size / 8 - 1;
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prg_bank_mask_32k = Cart.prg_size / 32 - 1;
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return true;
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}
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public override void SyncState(Serializer ser)
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{
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ser.Sync("reg_addr", ref reg_addr);
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ser.Sync("regs", ref regs);
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base.SyncState(ser);
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}
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public override void WriteEXP(int addr, byte value)
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{
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switch (addr & 0x01)
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{
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case 0x0000:
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reg_addr = value & 0x07;
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break;
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case 0x0001:
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switch (reg_addr)
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{
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case 2:
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regs[2] = (byte)(value & 0x01);
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break;
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case 4:
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regs[4] = (byte)(value & 0x01);
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break;
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case 5:
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regs[5] = (byte)(value & 0x07);
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break;
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case 6:
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regs[6] = (byte)(value & 0x03);
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break;
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case 7:
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int mirror = (value >> 1) & 0x03;
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switch (mirror)
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{
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case 0:
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SetMirrorType(EMirrorType.Horizontal);
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break;
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case 1:
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SetMirrorType(EMirrorType.Vertical);
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break;
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case 2:
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SetMirroring(0, 1, 1, 1);
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break;
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case 3:
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SetMirrorType(EMirrorType.OneScreenB);
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break;
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}
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break;
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}
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break;
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}
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}
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public override byte ReadPPU(int addr)
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{
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if (addr < 0x2000)
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{
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int chr_bank = regs[4] | (regs[6] << 1) | (regs[2] << 3);
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return VROM[((chr_bank & chr_bank_mask_8k) * 0x2000) + addr];
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}
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else
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{
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return base.ReadPPU(addr);
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}
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}
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public override byte ReadPRG(int addr)
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{
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return ROM[((regs[5] & prg_bank_mask_32k) * 0x8000) + addr];
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}
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}
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}
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