32 lines
879 B
C#
32 lines
879 B
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 is another 8K bankswitching method with two 4K banks. The rationale is that it's
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cheap and easy to implement with only a single 74HC153 or 253 dual 4:1 multiplexer.
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This multiplexer can act as a 1 bit latch AND the inverter for A12.
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To bankswitch, the following mask it used:
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A13 A0
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----------------
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0 1xxx xBxx xxxx
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Each bit corresponds to one of the 13 address lines. a 0 or 1 means that bit must be
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0 or 1 to trigger the bankswitch. x is a bit that is not concidered (it can be either
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0 or 1 and is thus a "don't care" bit).
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B is the bank we will select. sooo, accessing 0800 will select bank 0, and 0840
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will select bank 1.
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*/
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class m0840 : MapperBase
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{
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}
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}
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