71 lines
1.7 KiB
C#
71 lines
1.7 KiB
C#
namespace BizHawk.Emulation.Consoles.Atari._2600
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{
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/*
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EF (no name?)
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-----
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This is a fairly simple method that allows for up to 64K of ROM, using 16 4K banks.
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It works similar to F8, F6, etc. Only the addresses to perform the switch is
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1FE0-1FEF. Accessing one of these will select the desired bank. 1FE0 = bank 0,
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1FE1 = bank 1, etc.
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*/
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class mEF : MapperBase
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{
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private int toggle;
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private byte ReadMem(ushort addr, bool peek)
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{
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if (!peek)
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{
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Address(addr);
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}
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if (addr < 0x1000) return base.ReadMemory(addr);
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return core.rom[(toggle << 12) + (addr & 0xFFF)];
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}
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public override byte ReadMemory(ushort addr)
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{
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return ReadMem(addr, false);
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}
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public override byte PeekMemory(ushort addr)
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{
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return ReadMem(addr, true);
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}
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public override void WriteMemory(ushort addr, byte value)
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{
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Address(addr);
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if (addr < 0x1000) base.WriteMemory(addr, 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("toggle", ref toggle);
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}
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void Address(ushort addr)
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{
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if (addr == 0x1FE0) toggle = 0;
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if (addr == 0x1FE1) toggle = 1;
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if (addr == 0x1FE2) toggle = 2;
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if (addr == 0x1FE3) toggle = 3;
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if (addr == 0x1FE4) toggle = 4;
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if (addr == 0x1FE5) toggle = 5;
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if (addr == 0x1FE6) toggle = 6;
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if (addr == 0x1FE7) toggle = 7;
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if (addr == 0x1FE8) toggle = 8;
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if (addr == 0x1FE9) toggle = 9;
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if (addr == 0x1FEA) toggle = 10;
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if (addr == 0x1FEB) toggle = 11;
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if (addr == 0x1FEC) toggle = 12;
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if (addr == 0x1FED) toggle = 13;
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if (addr == 0x1FEE) toggle = 14;
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if (addr == 0x1FEF) toggle = 15;
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}
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}
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}
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