Mesen2/Core/NES/Mappers/Irem/IremG101.h
2022-09-08 21:29:52 -04:00

77 lines
No EOL
1.6 KiB
C++

#pragma once
#include "pch.h"
#include "NES/BaseMapper.h"
class IremG101 : public BaseMapper
{
protected:
uint16_t GetPrgPageSize() override { return 0x2000; }
uint16_t GetChrPageSize() override { return 0x0400; }
uint8_t _prgRegs[2] = {};
uint8_t _prgMode = 0;
void InitMapper() override
{
_prgRegs[0] = _prgRegs[1] = 0;
_prgMode = 0;
SelectPrgPage(2, -2);
SelectPrgPage(3, -1);
if(_romInfo.SubMapperID == 1) {
//032: 1 Major League
//CIRAM A10 is tied high (fixed one-screen mirroring) and PRG banking style is fixed as 8+8+16F
SetMirroringType(MirroringType::ScreenAOnly);
}
}
void Serialize(Serializer& s) override
{
BaseMapper::Serialize(s);
SV(_prgMode);
SV(_prgRegs[0]);
SV(_prgRegs[1]);
}
void UpdatePrgMode()
{
if(_prgMode == 0) {
SelectPrgPage(0, _prgRegs[0]);
SelectPrgPage(1, _prgRegs[1]);
SelectPrgPage(2, -2);
SelectPrgPage(3, -1);
} else {
SelectPrgPage(0, -2);
SelectPrgPage(1, _prgRegs[1]);
SelectPrgPage(2, _prgRegs[0]);
SelectPrgPage(3, -1);
}
}
void WriteRegister(uint16_t addr, uint8_t value) override
{
switch(addr & 0xF000) {
case 0x8000:
_prgRegs[0] = value & 0x1F;
SelectPrgPage(_prgMode == 0 ? 0 : 2, _prgRegs[0]);
break;
case 0x9000:
_prgMode = (value & 0x02) >> 1;
if(_romInfo.SubMapperID == 1) {
_prgMode = 0;
}
UpdatePrgMode();
SetMirroringType((value & 0x01) == 0x01 ? MirroringType::Horizontal : MirroringType::Vertical);
break;
case 0xA000:
_prgRegs[1] = value & 0x1F;
SelectPrgPage(1, _prgRegs[1]);
break;
case 0xB000:
SelectChrPage(addr & 0x07, value);
break;
}
}
};