47 lines
1.3 KiB
C#
47 lines
1.3 KiB
C#
namespace BizHawk.Emulation.Consoles.Nintendo
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{
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//pretty much just one game.
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//wires the mapper outputs to control the nametables. check out the companion board TLSROM
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public sealed class Mapper095 : Namcot108Board_Base
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{
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public override bool Configure(NES.EDetectionOrigin origin)
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{
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//analyze board type
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switch (Cart.board_type)
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{
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case "NAMCOT-3425": //dragon buster (J)
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AssertPrg(128); AssertChr(32); AssertVram(0); AssertWram(0);
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break;
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default:
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return false;
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}
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BaseSetup();
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SetMirrorType(EMirrorType.Vertical);
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return true;
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}
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int RewireNametable(int addr, int bitsel)
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{
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int bank_1k = mapper.Get_CHRBank_1K(addr & 0x1FFF);
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int nt = (bank_1k >> bitsel) & 1;
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int ofs = addr & 0x3FF;
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addr = 0x2000 + (nt << 10);
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addr |= (ofs);
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return addr;
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}
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//mapper 095's chief unique contribution is to add this nametable rewiring logic: CHR A15 directly controls CIRAM A10
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public override byte ReadPPU(int addr)
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{
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if (addr < 0x2000) return base.ReadPPU(addr);
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else return base.ReadPPU(RewireNametable(addr, 5));
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}
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public override void WritePPU(int addr, byte value)
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{
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if (addr < 0x2000) base.WritePPU(addr, value);
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else base.WritePPU(RewireNametable(addr, 5), value);
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}
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}
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} |