#pragma once #include "pch.h" #include "NES/BaseMapper.h" #include "NES/NesCpu.h" #include "NES/NesConsole.h" class Sunsoft3 : public BaseMapper { private: bool _irqLatch = false; bool _irqEnabled = false; uint16_t _irqCounter = 0; protected: uint16_t GetPrgPageSize() override { return 0x4000; } uint16_t GetChrPageSize() override { return 0x800; } bool EnableCpuClockHook() override { return true; } void InitMapper() override { SelectPrgPage(1, -1); } void Serialize(Serializer& s) override { BaseMapper::Serialize(s); SV(_irqLatch); SV(_irqEnabled); SV(_irqCounter); } void ProcessCpuClock() override { BaseProcessCpuClock(); if(_irqEnabled) { _irqCounter--; if(_irqCounter == 0xFFFF) { _irqEnabled = false; _console->GetCpu()->SetIrqSource(IRQSource::External); } } } void WriteRegister(uint16_t addr, uint8_t value) override { switch(addr & 0xF800) { case 0x8800: SelectChrPage(0, value); break; case 0x9800: SelectChrPage(1, value); break; case 0xA800: SelectChrPage(2, value); break; case 0xB800: SelectChrPage(3, value); break; case 0xC800: _irqCounter &= _irqLatch ? 0xFF00 : 0x00FF; _irqCounter |= _irqLatch ? value : (value << 8); _irqLatch = !_irqLatch; break; case 0xD800: _irqEnabled = (value & 0x10) == 0x10; _irqLatch = false; _console->GetCpu()->ClearIrqSource(IRQSource::External); break; case 0xE800: switch(value & 0x03) { case 0: SetMirroringType(MirroringType::Vertical); break; case 1: SetMirroringType(MirroringType::Horizontal); break; case 2: SetMirroringType(MirroringType::ScreenAOnly); break; case 3: SetMirroringType(MirroringType::ScreenBOnly); break; } break; case 0xF800: SelectPrgPage(0, value); break; } } };