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71 lines
1.6 KiB
C++
71 lines
1.6 KiB
C++
#pragma once
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#include "stdafx.h"
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#include "BaseMapper.h"
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#include "MemoryManager.h"
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class Txc22000 : public BaseMapper
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{
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private:
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uint8_t _state;
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bool _prgBankingMode;
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uint8_t _prgBank;
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protected:
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virtual uint16_t GetPRGPageSize() override { return 0x8000; }
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virtual uint16_t GetCHRPageSize() override { return 0x2000; }
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virtual uint16_t RegisterStartAddress() override { return 0x8000; }
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virtual uint16_t RegisterEndAddress() override { return 0xFFFF; }
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virtual bool AllowRegisterRead() override { return true; }
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void InitMapper() override
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{
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AddRegisterRange(0x4100, 0x5FFF, MemoryOperation::Any);
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RemoveRegisterRange(0x8000, 0xFFFF, MemoryOperation::Read);
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_state = 0;
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_prgBank = 0;
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_prgBankingMode = 0;
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SelectPRGPage(0, 0);
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SelectCHRPage(0, 0);
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}
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void StreamState(bool saving) override
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{
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BaseMapper::StreamState(saving);
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Stream(_state, _prgBank, _prgBankingMode);
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}
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virtual uint8_t ReadRegister(uint16_t addr) override
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{
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return MemoryManager::GetOpenBus() & 0xCF | (_state << 4);
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}
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void WriteRegister(uint16_t addr, uint8_t value) override
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{
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if(addr < 0x8000) {
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switch(addr & 0xE303) {
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//"when M=0, copy PP to RR. When M=1, RR=RR+1"
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case 0x4100:
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if(_prgBankingMode) {
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_state++;
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} else {
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_state = _prgBank;
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}
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break;
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case 0x4101: break; //"$4101: no visible effect"
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case 0x4102: _prgBank = (value >> 4) & 0x03; break;
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case 0x4103: _prgBankingMode = (value >> 4) & 0x01; break;
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case 0x4200: case 0x4201: case 0x4202: case 0x4203:
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SelectCHRPage(0, value & 0x0F);
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break;
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}
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} else {
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SelectPRGPage(0, _state);
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}
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}
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}; |