fceugx/source/fceultra/boards/228.cpp
2012-12-14 17:18:20 +00:00

85 lines
2.1 KiB
C++

/* FCE Ultra - NES/Famicom Emulator
*
* Copyright notice for this file:
* Copyright (C) 2012 CaH4e3
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "mapinc.h"
static uint8 mram[4], vreg;
static uint16 areg;
static SFORMAT StateRegs[] =
{
{ mram, 4, "MRAM" },
{ &areg, 2, "AREG" },
{ &vreg, 1, "VREG" },
{ 0 }
};
static void Sync(void) {
uint32 prgl, prgh, page = (areg >> 7) & 0x3F;
if ((page & 0x30) == 0x30)
page -= 0x10;
prgl = prgh = (page << 1) + (((areg >> 6) & 1) & ((areg >> 5) & 1));
prgh += ((areg >> 5) & 1) ^ 1;
setmirror(((areg >> 13) & 1) ^ 1);
setprg16(0x8000,prgl);
setprg16(0xc000,prgh);
setchr8(((vreg & 0x3) | ((areg & 0xF) << 2)));
}
static DECLFW(M228RamWrite) {
mram[A & 3] = V & 0x0F;
}
static DECLFR(M228RamRead) {
return mram[A & 3];
}
static DECLFW(M228Write) {
areg = A;
vreg = V;
Sync();
}
static void M228Reset(void) {
areg = 0x8000;
vreg = 0;
Sync();
}
static void M228Power(void) {
M228Reset();
SetReadHandler(0x5000,0x5FFF,M228RamRead);
SetWriteHandler(0x5000,0x5FFF,M228RamWrite);
SetReadHandler(0x8000, 0xFFFF, CartBR);
SetWriteHandler(0x8000, 0xFFFF, M228Write);
}
static void StateRestore(int version) {
Sync();
}
void Mapper228_Init(CartInfo *info) {
info->Reset = M228Reset;
info->Power = M228Power;
GameStateRestore = StateRestore;
AddExState(&StateRegs, ~0, 0, 0);
}