mirror of
https://github.com/SourMesen/Mesen2.git
synced 2025-04-02 10:21:44 -04:00
133 lines
3.3 KiB
C++
133 lines
3.3 KiB
C++
#pragma once
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#include "pch.h"
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#include "NES/BaseMapper.h"
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#include "NES/NesCpu.h"
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#include "NES/NesConsole.h"
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#include "NES/NesMemoryManager.h"
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class Yoko : public BaseMapper
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{
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uint8_t _regs[7] = {};
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uint8_t _exRegs[4] = {};
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uint8_t _mode = 0;
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uint8_t _bank = 0;
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uint16_t _irqCounter = 0;
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bool _irqEnabled = false;
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protected:
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uint32_t GetDipSwitchCount() override { return 2; }
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uint16_t RegisterStartAddress() override { return 0x5000; }
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uint16_t RegisterEndAddress() override { return 0x5FFF; }
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uint16_t GetPrgPageSize() override { return 0x2000; }
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uint16_t GetChrPageSize() override { return 0x800; }
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bool AllowRegisterRead() override { return true; }
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bool EnableCpuClockHook() override { return true; }
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void InitMapper() override
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{
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memset(_regs, 0, sizeof(_regs));
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memset(_exRegs, 0, sizeof(_exRegs));
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_mode = 0;
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_bank = 0;
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_irqCounter = 0;
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_irqEnabled = false;
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RemoveRegisterRange(0x5000, 0x53FF, MemoryOperation::Write);
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AddRegisterRange(0x8000, 0xFFFF, MemoryOperation::Write);
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UpdateState();
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}
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void Serialize(Serializer& s) override
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{
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BaseMapper::Serialize(s);
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SVArray(_regs, 7);
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SVArray(_exRegs, 4);
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SV(_mode);
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SV(_bank);
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SV(_irqCounter);
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SV(_irqEnabled);
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}
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void Reset(bool softReset) override
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{
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if(softReset) {
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_mode = 0;
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_bank = 0;
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}
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}
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void ProcessCpuClock() override
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{
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BaseProcessCpuClock();
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if(_irqEnabled) {
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_irqCounter--;
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if(_irqCounter == 0) {
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_irqEnabled = false;
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_irqCounter = 0xFFFF;
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_console->GetCpu()->SetIrqSource(IRQSource::External);
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}
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}
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}
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void UpdateState()
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{
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SetMirroringType(_mode & 0x01 ? MirroringType::Horizontal : MirroringType::Vertical);
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SelectChrPage(0, _regs[3]);
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SelectChrPage(1, _regs[4]);
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SelectChrPage(2, _regs[5]);
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SelectChrPage(3, _regs[6]);
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if(_mode & 0x10) {
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uint32_t outer = (_bank & 0x08) << 1;
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SelectPrgPage(0, outer | (_regs[0] & 0x0F));
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SelectPrgPage(1, outer | (_regs[1] & 0x0F));
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SelectPrgPage(2, outer | (_regs[2] & 0x0F));
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SelectPrgPage(3, outer | 0x0F);
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} else if(_mode & 0x08) {
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SelectPrgPage4x(0, (_bank & 0xFE) << 1);
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} else {
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SelectPrgPage2x(0, _bank << 1);
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SelectPrgPage2x(1, -2);
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}
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}
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uint8_t ReadRegister(uint16_t addr) override
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{
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if(addr <= 0x53FF) {
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return (_console->GetMemoryManager()->GetOpenBus() & 0xFC) | GetDipSwitches();
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} else {
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return _exRegs[addr & 0x03];
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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 < 0x8000) {
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_exRegs[addr & 0x03] = value;
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} else {
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switch(addr & 0x8C17) {
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case 0x8000: _bank = value; UpdateState(); break;
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case 0x8400: _mode = value; UpdateState(); break;
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case 0x8800:
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_irqCounter = (_irqCounter & 0xFF00) | value;
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_console->GetCpu()->ClearIrqSource(IRQSource::External);
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break;
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case 0x8801:
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_irqEnabled = (_mode & 0x80) != 0;
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_irqCounter = (_irqCounter & 0xFF) | (value << 8);
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break;
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case 0x8c00: _regs[0] = value; UpdateState(); break;
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case 0x8c01: _regs[1] = value; UpdateState(); break;
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case 0x8c02: _regs[2] = value; UpdateState(); break;
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case 0x8c10: _regs[3] = value; UpdateState(); break;
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case 0x8c11: _regs[4] = value; UpdateState(); break;
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case 0x8c16: _regs[5] = value; UpdateState(); break;
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case 0x8c17: _regs[6] = value; UpdateState(); break;
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}
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}
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}
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};
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