Mesen/Core/IremG101.h
2016-12-17 23:14:47 -05:00

75 lines
1.7 KiB
C++

#pragma once
#include "stdafx.h"
#include "BaseMapper.h"
class IremG101 : public BaseMapper
{
protected:
virtual uint16_t GetPRGPageSize() override { return 0x2000; }
virtual uint16_t GetCHRPageSize() override { return 0x0400; }
uint8_t _prgRegs[2];
uint8_t _prgMode;
void InitMapper() override
{
_prgRegs[0] = _prgRegs[1] = 0;
_prgMode = 0;
SelectPRGPage(2, -2);
SelectPRGPage(3, -1);
if(_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);
}
}
virtual void StreamState(bool saving) override
{
BaseMapper::StreamState(saving);
Stream(_prgMode, _prgRegs[0], _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(_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;
}
}
};