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https://github.com/SourMesen/Mesen.git
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118 lines
3.1 KiB
C++
118 lines
3.1 KiB
C++
#pragma once
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#include "stdafx.h"
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#include "MMC3.h"
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class MMC3_121 : public MMC3
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{
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private:
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uint8_t _exRegs[8];
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protected:
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virtual bool AllowRegisterRead() override { return true; }
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virtual void InitMapper() override
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{
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MMC3::InitMapper();
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AddRegisterRange(0x5000, 0x5FFF, MemoryOperation::Any);
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RemoveRegisterRange(0x8000, 0xFFFF, MemoryOperation::Read);
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}
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virtual void Reset(bool softReset) override
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{
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memset(_exRegs, 0, sizeof(_exRegs));
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_exRegs[3] = 0x80;
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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 _exRegs[4];
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}
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void SelectPRGPage(uint16_t slot, uint16_t page, PrgMemoryType memoryType = PrgMemoryType::PrgRom) override
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{
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uint8_t orValue = (_exRegs[3] & 0x80) >> 2;
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if(_exRegs[5] & 0x3F) {
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BaseMapper::SelectPRGPage(slot, (page & 0x1F) | orValue, memoryType);
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BaseMapper::SelectPRGPage(1, _exRegs[2] | orValue, memoryType);
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BaseMapper::SelectPRGPage(2, _exRegs[1] | orValue, memoryType);
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BaseMapper::SelectPRGPage(3, _exRegs[0] | orValue, memoryType);
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} else {
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BaseMapper::SelectPRGPage(slot, (page & 0x1F) | orValue, memoryType);
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}
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}
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void SelectCHRPage(uint16_t slot, uint16_t page, ChrMemoryType memoryType) override
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{
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if(_prgSize == _chrRomSize) {
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//Hack for Super 3-in-1
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BaseMapper::SelectCHRPage(slot, page | ((_exRegs[3] & 0x80) << 1), memoryType);
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} else {
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if((slot < 4 && _chrMode == 0) || (slot >= 4 && _chrMode == 1)) {
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page |= 0x100;
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}
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BaseMapper::SelectCHRPage(slot, page, memoryType);
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}
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}
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void UpdateExRegs()
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{
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switch(_exRegs[5] & 0x3F) {
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case 0x20: _exRegs[7] = 1; _exRegs[0] = _exRegs[6]; break;
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case 0x29: _exRegs[7] = 1; _exRegs[0] = _exRegs[6]; break;
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case 0x26: _exRegs[7] = 0; _exRegs[0] = _exRegs[6]; break;
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case 0x2B: _exRegs[7] = 1; _exRegs[0] = _exRegs[6]; break;
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case 0x2C:
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_exRegs[7] = 1;
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if(_exRegs[6]) {
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_exRegs[0] = _exRegs[6];
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}
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break;
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case 0x3C:
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case 0x3F: _exRegs[7] = 1; _exRegs[0] = _exRegs[6]; break;
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case 0x28: _exRegs[7] = 0; _exRegs[1] = _exRegs[6]; break;
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case 0x2A: _exRegs[7] = 0; _exRegs[2] = _exRegs[6]; break;
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case 0x2F: break;
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default: _exRegs[5] = 0; break;
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}
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}
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virtual void WriteRegister(uint16_t addr, uint8_t value) override
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{
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if(addr < 0x8000) {
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//$5000-$5FFF
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const uint8_t lookup[] = { 0x83, 0x83, 0x42, 0x00 };
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_exRegs[4] = lookup[value & 0x03];
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if((addr & 0x5180) == 0x5180) {
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//Hack for Super 3-in-1
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_exRegs[3] = value;
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UpdateState();
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}
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} else if(addr < 0xA000) {
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//$8000-$9FFF
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if((addr & 0x03) == 0x03) {
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_exRegs[5] = value;
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UpdateExRegs();
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MMC3::WriteRegister(0x8000, value);
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} else if(addr & 0x01) {
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_exRegs[6] = ((value & 0x01) << 5) | ((value & 0x02) << 3) | ((value & 0x04) << 1) | ((value & 0x08) >> 1) | ((value & 0x10) >> 3) | ((value & 0x20) >> 5);
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if(!_exRegs[7]) {
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UpdateExRegs();
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}
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MMC3::WriteRegister(0x8001, value);
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} else {
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MMC3::WriteRegister(0x8000, value);
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}
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} else {
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MMC3::WriteRegister(addr, value);
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}
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}
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virtual void StreamState(bool saving) override
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{
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MMC3::StreamState(saving);
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ArrayInfo<uint8_t> exRegs{ _exRegs, 8 };
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Stream(exRegs);
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}
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}; |