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https://github.com/libretro/Mesen.git
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88 lines
2.2 KiB
C++
88 lines
2.2 KiB
C++
#pragma once
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#include "stdafx.h"
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#include "MMC3.h"
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class MMC3_126 : public MMC3
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{
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private:
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uint8_t _exRegs[4];
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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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uint16_t reg = _exRegs[0];
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page &= ((~reg >> 2) & 0x10) | 0x0F;
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page |= (reg & (0x06 | (reg & 0x40) >> 6)) << 4 | (reg & 0x10) << 3;
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if(!(_exRegs[3] & 0x03)) {
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MMC3::SelectPRGPage(slot, page, memoryType);
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} else if((_prgMode << 1) == slot) {
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if((_exRegs[3] & 0x03) == 0x03) {
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MMC3::SelectPRGPage(0, page, memoryType);
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MMC3::SelectPRGPage(1, page + 1, memoryType);
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MMC3::SelectPRGPage(2, page + 2, memoryType);
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MMC3::SelectPRGPage(3, page + 3, memoryType);
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} else {
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MMC3::SelectPRGPage(0, page, memoryType);
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MMC3::SelectPRGPage(1, page + 1, memoryType);
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MMC3::SelectPRGPage(2, page, memoryType);
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MMC3::SelectPRGPage(3, page + 1, memoryType);
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}
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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(!(_exRegs[3] & 0x10)) {
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MMC3::SelectCHRPage(slot, GetChrOuterBank() | (page & ((_exRegs[0] & 0x80) - 1)));
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}
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}
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uint16_t GetChrOuterBank()
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{
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uint16_t reg = _exRegs[0];
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return
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(~reg << 0 & 0x0080 & _exRegs[2]) |
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(reg << 4 & 0x0080 & reg) |
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(reg << 3 & 0x0100) |
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(reg << 5 & 0x0200);
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}
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void InitMapper() override
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{
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MMC3::InitMapper();
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memset(_exRegs, 0, sizeof(_exRegs));
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AddRegisterRange(0x6000, 0x8000, MemoryOperation::Write);
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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 WriteRegister(uint16_t addr, uint8_t value) override
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{
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if(addr < 0x8000) {
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addr &= 0x03;
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if(addr == 0x01 || addr == 0x02 || ((addr == 0x00 || addr == 0x03) && !(_exRegs[3] & 0x80))) {
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if(_exRegs[addr] != value) {
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_exRegs[addr] = value;
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if(_exRegs[3] & 0x10) {
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uint16_t page = GetChrOuterBank() | ((_exRegs[2] & 0x0F) << 3);
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for(int i = 0; i < 8; i++) {
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MMC3::SelectCHRPage(i, page + i);
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}
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} else {
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MMC3::UpdateChrMapping();
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}
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MMC3::UpdatePrgMapping();
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}
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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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}; |