116 lines
3.2 KiB
C#
116 lines
3.2 KiB
C#
//////////////////////////////////////////////////////////////////////////
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// Mapper006 FFE F4xxx //
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//////////////////////////////////////////////////////////////////////////
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using System;
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using static VirtualNes.Core.CPU;
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using static VirtualNes.MMU;
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using BYTE = System.Byte;
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using INT = System.Int32;
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namespace VirtualNes.Core
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{
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public class Mapper006 : Mapper
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{
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BYTE irq_enable;
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INT irq_counter;
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public Mapper006(NES parent) : base(parent) { }
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public override void Reset()
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{
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SetPROM_32K_Bank(0, 1, 14, 15);
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if (VROM_1K_SIZE != 0)
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{
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SetVROM_8K_Bank(0);
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}
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else
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{
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SetCRAM_8K_Bank(0);
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}
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irq_enable = 0;
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irq_counter = 0;
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}
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//void Mapper006::WriteLow(WORD addr, BYTE data)
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public override void WriteLow(ushort addr, byte data)
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{
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switch (addr)
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{
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case 0x42FE:
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if ((data & 0x10) != 0) SetVRAM_Mirror(VRAM_MIRROR4H);
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else SetVRAM_Mirror(VRAM_MIRROR4L);
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break;
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case 0x42FF:
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if ((data & 0x10) != 0) SetVRAM_Mirror(VRAM_HMIRROR);
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else SetVRAM_Mirror(VRAM_VMIRROR);
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break;
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case 0x4501:
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irq_enable = 0;
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nes.cpu.ClrIRQ(IRQ_MAPPER);
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break;
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case 0x4502:
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irq_counter = (irq_counter & 0xFF00) | data;
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break;
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case 0x4503:
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irq_counter = (irq_counter & 0x00FF) | ((INT)data << 8);
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irq_enable = 0xFF;
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nes.cpu.ClrIRQ(IRQ_MAPPER);
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break;
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default:
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base.WriteLow(addr, data);
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break;
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}
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}
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//void Mapper006::Write(WORD addr, BYTE data)
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public override void Write(ushort addr, byte data)
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{
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SetPROM_16K_Bank(4, (data & 0x3C) >> 2);
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SetCRAM_8K_Bank(data & 0x03);
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}
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//void Mapper006::HSync(INT scanline)
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public override void HSync(int scanline)
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{
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if (irq_enable != 0)
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{
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irq_counter += 133;
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if (irq_counter >= 0xFFFF)
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{
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// nes.cpu.IRQ();
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irq_counter = 0;
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nes.cpu.SetIRQ(IRQ_MAPPER);
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}
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}
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}
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//void Mapper006::SaveState(LPBYTE p)
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public override void SaveState(byte[] p)
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{
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p[0] = irq_enable;
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//*(INT*)&p[1] = irq_counter;
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BitConverter.GetBytes(irq_counter).CopyTo(p, 1);
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}
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//void Mapper006::LoadState(LPBYTE p)
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public override void LoadState(byte[] p)
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{
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irq_enable = p[0];
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//irq_counter = *(INT*)&p[1];
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irq_counter = BitConverter.ToInt32(p, 1);
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}
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public override bool IsStateSave()
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{
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return true;
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}
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}
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}
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