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95 lines
2.6 KiB
C++
95 lines
2.6 KiB
C++
#pragma once
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#include "stdafx.h"
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#include "BaseMapper.h"
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class Action53 : public BaseMapper
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{
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private:
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uint8_t _selectedReg;
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uint8_t _regs[4];
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uint8_t _mirroringBit;
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protected:
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virtual uint16_t GetPRGPageSize() override { return 0x4000; }
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virtual uint16_t GetCHRPageSize() override { return 0x2000; }
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void InitMapper() override
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{
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_selectedReg = 0;
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memset(_regs, 0, sizeof(_regs));
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AddRegisterRange(0x5000, 0x5FFF, MemoryOperation::Write);
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SelectPRGPage(1, -1);
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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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ArrayInfo<uint8_t> regs{ _regs,4 };
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Stream(_selectedReg, _mirroringBit, regs);
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if(!saving) {
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UpdateState();
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}
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}
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void UpdateState()
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{
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uint8_t mirroring = _regs[2] & 0x03;
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if(!(mirroring & 0x02)) {
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mirroring = _mirroringBit;
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}
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switch(mirroring) {
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case 0: SetMirroringType(MirroringType::ScreenAOnly); break;
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case 1: SetMirroringType(MirroringType::ScreenBOnly); break;
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case 2: SetMirroringType(MirroringType::Vertical); break;
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case 3: SetMirroringType(MirroringType::Horizontal); break;
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}
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uint8_t gameSize = (_regs[2] & 0x30) >> 4;
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uint8_t prgSize = (_regs[2] & 0x08) >> 3;
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uint8_t slotSelect = (_regs[2] & 0x04) >> 2;
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uint8_t chrSelect = _regs[0] & 0x03;
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uint8_t prgSelect = _regs[1] & 0x0F;
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uint8_t outerPrgSelect = (_regs[3] & 0x3F) << 1;
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SelectCHRPage(0, chrSelect);
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if(prgSize) {
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uint8_t bank = (slotSelect ? 0 : 1);
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switch(gameSize) {
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case 0: SelectPRGPage(bank, (outerPrgSelect & 0x7E) | (prgSelect & 0x01)); break;
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case 1: SelectPRGPage(bank, (outerPrgSelect & 0x7C) | (prgSelect & 0x03)); break;
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case 2: SelectPRGPage(bank, (outerPrgSelect & 0x78) | (prgSelect & 0x07)); break;
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case 3: SelectPRGPage(bank, (outerPrgSelect & 0x70) | (prgSelect & 0x0F)); break;
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}
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SelectPRGPage(slotSelect ? 1 : 0, (outerPrgSelect & 0x7E) | slotSelect);
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} else {
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prgSelect <<= 1;
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uint8_t outerAnd[4]{ 0x7E, 0x7C, 0x78, 0x70 };
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uint8_t innerAnd[4]{ 0x01, 0x03, 0x07, 0x0F };
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SelectPRGPage(0, (outerPrgSelect & outerAnd[gameSize]) | (prgSelect & innerAnd[gameSize]));
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SelectPRGPage(1, (outerPrgSelect & outerAnd[gameSize]) | ((prgSelect | 0x01) & innerAnd[gameSize]));
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}
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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 <= 0x5FFF) {
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_selectedReg = ((value & 0x80) >> 6) | (value & 0x01);
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} else if(addr >= 0x8000) {
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if(_selectedReg <= 1) {
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_mirroringBit = (value >> 4) & 0x01;
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} else if(_selectedReg == 2) {
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_mirroringBit = (value & 0x01);
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}
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_regs[_selectedReg] = value & 0x3F;
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UpdateState();
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}
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}
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};
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