mirror of
https://github.com/libretro/Mesen.git
synced 2024-11-23 17:19:39 +00:00
55 lines
1.3 KiB
C++
55 lines
1.3 KiB
C++
#pragma once
|
||
#include "stdafx.h"
|
||
#include "MMC3.h"
|
||
|
||
//iNES Mapper 224 is used for the <20>»‰È‘× (Jncota) KT-008 PCB. It's an MMC3 clone that supports 1024 KiB of PRG-ROM
|
||
//through an additional outer bank register at $5000.
|
||
//http://wiki.nesdev.com/w/index.php/INES_Mapper_224
|
||
class MMC3_224 : public MMC3
|
||
{
|
||
private:
|
||
uint8_t _outerBank;
|
||
|
||
protected:
|
||
void InitMapper() override
|
||
{
|
||
_outerBank = 0;
|
||
|
||
AddRegisterRange(0x5000, 0x5003, MemoryOperation::Write);
|
||
MMC3::InitMapper();
|
||
}
|
||
|
||
void StreamState(bool saving) override
|
||
{
|
||
MMC3::StreamState(saving);
|
||
Stream(_outerBank);
|
||
}
|
||
|
||
void UpdatePrgMapping() override
|
||
{
|
||
uint8_t outerBank = _outerBank << 6;
|
||
if(_prgMode == 0) {
|
||
SelectPRGPage(0, (_registers[6] & 0x3F) | outerBank);
|
||
SelectPRGPage(1, (_registers[7] & 0x3F) | outerBank);
|
||
SelectPRGPage(2, 0x3E | outerBank);
|
||
SelectPRGPage(3, 0x3F | outerBank);
|
||
} else if(_prgMode == 1) {
|
||
SelectPRGPage(0, 0x3E | outerBank);
|
||
SelectPRGPage(1, (_registers[6] & 0x3F) | outerBank);
|
||
SelectPRGPage(2, (_registers[7] & 0x3F) | outerBank);
|
||
SelectPRGPage(3, 0x3F | outerBank);
|
||
}
|
||
}
|
||
|
||
void WriteRegister(uint16_t addr, uint8_t value) override
|
||
{
|
||
if(addr < 0x8000) {
|
||
if(addr == 0x5000) {
|
||
_outerBank = (value >> 2) & 0x01;
|
||
UpdatePrgMapping();
|
||
}
|
||
} else {
|
||
MMC3::WriteRegister(addr, value);
|
||
}
|
||
}
|
||
}; |