mirror of
https://github.com/libretro/Mesen.git
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130 lines
2.7 KiB
C++
130 lines
2.7 KiB
C++
#pragma once
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#include "stdafx.h"
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#include "MMC3.h"
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class MMC3_217 : public MMC3
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{
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private:
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uint8_t _exRegs[4];
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uint8_t _lut[8] = { 0,6,3,7,5,2,4,1 };
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protected:
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void InitMapper() override
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{
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AddRegisterRange(0x5000, 0x5001, MemoryOperation::Write);
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AddRegisterRange(0x5007, 0x5007, MemoryOperation::Write);
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MMC3::InitMapper();
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}
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void Reset(bool softReset) override
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{
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_exRegs[0] = 0;
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_exRegs[1] = 0xFF;
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_exRegs[2] = 0x03;
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_exRegs[3] = 0;
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BaseMapper::Reset(softReset);
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UpdateState();
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}
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void StreamState(bool saving) override
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{
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MMC3::StreamState(saving);
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Stream(_exRegs[0], _exRegs[1], _exRegs[2], _exRegs[3]);
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}
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void SelectCHRPage(uint16_t slot, uint16_t page, ChrMemoryType memoryType = ChrMemoryType::Default) override
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{
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if(!(_exRegs[1] & 0x08)) {
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page = (_exRegs[1] << 3 & 0x80) | (page & 0x7F);
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}
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MMC3::SelectCHRPage(slot, (_exRegs[1] << 8 & 0x0300) | page);
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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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if(_exRegs[1] & 0x08) {
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page = (page & 0x1F);
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} else {
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page = (page & 0x0F) | (_exRegs[1] & 0x10);
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}
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MMC3::SelectPRGPage(slot, (_exRegs[1] << 5 & 0x60) | page);
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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) {
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case 0x5000:
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_exRegs[0] = value;
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if(value & 0x80) {
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value = (value & 0x0F) | (_exRegs[1] << 4 & 0x30);
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value <<= 1;
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SelectPRGPage(0, value);
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SelectPRGPage(1, value + 1);
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SelectPRGPage(2, value);
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SelectPRGPage(3, value + 1);
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} else {
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UpdatePrgMapping();
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}
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break;
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case 0x5001:
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if(_exRegs[1] != value) {
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_exRegs[1] = value;
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UpdatePrgMapping();
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}
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break;
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case 0x5007:
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_exRegs[2] = value;
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break;
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}
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} else {
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switch(addr & 0xE001) {
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case 0x8000:
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MMC3::WriteRegister(_exRegs[2] ? 0xC000 : 0x8000, value);
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break;
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case 0x8001:
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if(_exRegs[2]) {
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value = (value & 0xC0) | _lut[value & 0x07];
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_exRegs[3] = 1;
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MMC3::WriteRegister(0x8000, value);
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} else {
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MMC3::WriteRegister(0x8001, value);
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}
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break;
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case 0xA000:
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if(_exRegs[2]) {
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if(_exRegs[3] && ((_exRegs[0] & 0x80) == 0 || GetCurrentRegister() < 6)) {
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_exRegs[3] = 0;
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MMC3::WriteRegister(0x8001, value);
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}
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} else {
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SetMirroringType(value & 0x01 ? MirroringType::Horizontal : MirroringType::Vertical);
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}
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break;
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case 0xA001:
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if(_exRegs[2]) {
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SetMirroringType(value & 0x01 ? MirroringType::Horizontal : MirroringType::Vertical);
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} else {
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MMC3::WriteRegister(0xA001, value);
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}
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break;
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default:
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MMC3::WriteRegister(addr, value);
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break;
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}
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}
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}
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}; |