58 lines
1.3 KiB
C#
58 lines
1.3 KiB
C#
namespace BizHawk.Emulation.Consoles.Nintendo
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{
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//this board contains a Namcot 109 and some extra ram for nametables
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public class DRROM : 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 "NES-DRROM": //gauntlet (U)
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case "TENGEN-800004": // gauntlet (Unl)
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AssertPrg(128); AssertChr(64); AssertVram(2); 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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SetMirroring(0, 1, 0, 1);
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return true;
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}
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//the addressing logic for nametables is a bit speculative here
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//how it is wired back to the NES and locally mirrored is unknown,
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//but it probably doesnt matter in practice.
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//still, purists could validate it.
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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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//read patterns from mapper controlled area
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return base.ReadPPU(addr);
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}
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else if (addr < 0x2800)
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{
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return VRAM[addr - 0x2000];
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}
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else return base.ReadPPU(addr);
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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)
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{
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//nothing wired here
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}
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else if (addr < 0x2800)
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{
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VRAM[addr - 0x2000] = value;
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}
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else base.WritePPU(addr, value);
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}
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}
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} |