51 lines
1.2 KiB
C#
51 lines
1.2 KiB
C#
using System;
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using System.Collections.Generic;
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using System.Linq;
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using System.Text;
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namespace BizHawk.Emulation.Consoles.Atari._2600
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{
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/*
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This was used by Commavid. It allowed for both ROM and RAM on the cartridge,
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without using bankswitching. There's 2K of ROM and 1K of RAM.
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2K of ROM is mapped at 1800-1FFF.
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1K of RAM is mapped in at 1000-17FF.
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The read port is at 1000-13FF.
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The write port is at 1400-17FF.
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Example games:
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Magicard
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*/
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class mCV: MapperBase
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{
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ByteBuffer aux_ram = new ByteBuffer(1024);
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public override byte ReadMemory(ushort addr)
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{
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if (addr < 0x1000)
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return base.ReadMemory(addr);
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else if (addr < 0x1400)
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return aux_ram[(addr & 0x3FF)];
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else if (addr >= 0x1800 && addr < 0x2000)
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return core.rom[(addr & 0x7FF)];
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else return base.ReadMemory(addr);
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}
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public override void WriteMemory(ushort addr, byte value)
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{
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if (addr < 0x1000)
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base.WriteMemory(addr, value);
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else if (addr >= 0x1400 && addr < 0x1800)
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aux_ram[(addr & 0x3FF)] = value;
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}
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public override void SyncState(Serializer ser)
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{
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base.SyncState(ser);
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ser.Sync("aux_ram", ref aux_ram);
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}
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}
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}
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