forked from sin365/AxibugEmuOnline
97 lines
2.8 KiB
C#
97 lines
2.8 KiB
C#
//////////////////////////////////////////////////////////////////////////
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// Mapper073 Konami VRC3 //
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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 Mapper073 : Mapper
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{
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BYTE irq_enable;
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INT irq_counter;
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public Mapper073(NES parent) : base(parent)
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{
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}
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public override void Reset()
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{
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irq_enable = 0;
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irq_counter = 0;
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SetPROM_32K_Bank(0, 1, PROM_8K_SIZE - 2, PROM_8K_SIZE - 1);
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}
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//void Mapper073::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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switch (addr)
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{
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case 0xF000:
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SetPROM_16K_Bank(4, data);
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break;
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case 0x8000:
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irq_counter = (irq_counter & 0xFFF0) | (data & 0x0F);
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break;
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case 0x9000:
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irq_counter = (irq_counter & 0xFF0F) | ((data & 0x0F) << 4);
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break;
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case 0xA000:
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irq_counter = (irq_counter & 0xF0FF) | ((data & 0x0F) << 8);
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break;
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case 0xB000:
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irq_counter = (irq_counter & 0x0FFF) | ((data & 0x0F) << 12);
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break;
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case 0xC000:
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irq_enable = (byte)(data & 0x02);
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nes.cpu.ClrIRQ(IRQ_MAPPER);
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break;
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case 0xD000:
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nes.cpu.ClrIRQ(IRQ_MAPPER);
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break;
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}
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}
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//void Mapper073::Clock(INT cycles)
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public override void Clock(int cycles)
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{
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if (irq_enable != 0)
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{
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if ((irq_counter += cycles) >= 0xFFFF)
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{
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irq_enable = 0;
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irq_counter &= 0xFFFF;
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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 Mapper073::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 Mapper073::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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