fceux/boards/8237.c

94 lines
2.3 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"
#include "mmc3.h"
static uint8 cmdin;
static uint8 UNL8237_perm[8] = {0, 2, 6, 1, 7, 3, 4, 5};
static void UNL8237CW(uint32 A, uint8 V)
{
setchr1(A,((EXPREGS[1]&4)<<6)|V);
}
static void UNL8237PW(uint32 A, uint8 V)
{
if(EXPREGS[0]&0x80)
{
if(EXPREGS[0]&0x20)
setprg32(0x8000,(EXPREGS[0]&0xF)>>1);
else
{
setprg16(0x8000,(EXPREGS[0]&0x1F));
setprg16(0xC000,(EXPREGS[0]&0x1F));
}
}
else
setprg8(A,V&0x3F);
}
static DECLFW(UNL8237Write)
{
if((A&0xF000)==0xF000)
IRQCount=V;
else if((A&0xF000)==0xE000)
X6502_IRQEnd(FCEU_IQEXT);
else switch(A&0xE001)
{
case 0x8000: setmirror(((V|(V>>7))&1)^1); break;
case 0xA000: MMC3_CMDWrite(0x8000,(V&0xC0)|(UNL8237_perm[V&7])); cmdin=1; break;
case 0xC000: if(cmdin)
{
MMC3_CMDWrite(0x8001,V);
cmdin=0;
}
break;
}
}
static DECLFW(UNL8237ExWrite)
{
switch(A)
{
case 0x5000: EXPREGS[0]=V; FixMMC3PRG(MMC3_cmd); break;
case 0x5001: EXPREGS[1]=V; FixMMC3CHR(MMC3_cmd); break;
}
}
static void UNL8237Power(void)
{
IRQa=1;
EXPREGS[0]=EXPREGS[1]=0;
GenMMC3Power();
SetWriteHandler(0x8000,0xFFFF,UNL8237Write);
SetWriteHandler(0x5000,0x7FFF,UNL8237ExWrite);
}
void UNL8237_Init(CartInfo *info)
{
GenMMC3_Init(info, 256, 256, 0, 0);
cwrap=UNL8237CW;
pwrap=UNL8237PW;
info->Power=UNL8237Power;
AddExState(EXPREGS, 3, 0, "EXPR");
AddExState(&cmdin, 1, 0, "CMDIN");
}