fceux/boards/8157.cpp

82 lines
1.9 KiB
C++

/* FCE Ultra - NES/Famicom Emulator
*
* Copyright notice for this file:
* Copyright (C) 2005 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "mapinc.h"
static uint16 cmdreg;
static uint8 invalid_data;
static SFORMAT StateRegs[]=
{
{&invalid_data, 1, "INVD"},
{&cmdreg, 2, "CMDREG"},
{0}
};
static void Sync(void)
{
setprg16r((cmdreg&0x060)>>5,0x8000,(cmdreg&0x01C)>>2);
setprg16r((cmdreg&0x060)>>5,0xC000,(cmdreg&0x200)?(~0):0);
setmirror(((cmdreg&2)>>1)^1);
}
static DECLFR(UNL8157Read)
{
if(invalid_data&&cmdreg&0x100)
return 0xFF;
else
return CartBR(A);
}
static DECLFW(UNL8157Write)
{
cmdreg=A;
Sync();
}
static void UNL8157Power(void)
{
setchr8(0);
SetWriteHandler(0x8000,0xFFFF,UNL8157Write);
SetReadHandler(0x8000,0xFFFF,UNL8157Read);
cmdreg=0x200;
invalid_data=1;
Sync();
}
static void UNL8157Reset(void)
{
cmdreg=0;
invalid_data^=1;
Sync();
}
static void UNL8157Restore(int version)
{
Sync();
}
void UNL8157_Init(CartInfo *info)
{
info->Power=UNL8157Power;
info->Reset=UNL8157Reset;
GameStateRestore=UNL8157Restore;
AddExState(&StateRegs, ~0, 0, 0);
}