fceugx/source/boards/8237.c
2008-04-03 03:58:35 +00:00

154 lines
2.9 KiB
C

/* FCE Ultra - NES/Famicom Emulator
*
* Copyright notice for this file:
* Copyright (C) 2002 Xodnizel
*
* 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 uint8 cmdin;
static uint8 cmd;
static uint8 regs[8];
static uint8 master,chrm;
static int32 IRQCount,IRQa;
static void DoPRG(void)
{
if(master&0x80)
{
if(master&0x20)
{
setprg32(0x8000,(master&0xF)>>1);
}
else
{
setprg16(0x8000,master&0xF);
setprg16(0xC000,master&0xF);
}
}
else
{
setprg8(0xA000,regs[4]);
setprg8(0xE000,~0);
if(cmd&0x40)
{
setprg8(0xC000,regs[2]);
setprg8(0x8000,~1);
}
else
{
setprg8(0x8000,regs[2]);
setprg8(0xC000,~1);
}
}
}
static void DoCHR(void)
{
uint32 base=(cmd&0x80)<<5;
int orie=(chrm&0x4)<<6;
setchr2(0x0000^base,(orie|regs[0])>>1); //K
setchr2(0x0800^base,(orie|regs[3])>>1); //43
setchr1(0x1000,orie|regs[1]);
setchr1(0x1400,orie|regs[5]);
setchr1(0x1800,orie|regs[6]);
setchr1(0x1c00,orie|regs[7]);
}
static DECLFW(UNL8237Write)
{
switch(A&0xF000)
{
case 0xf000:IRQCount=V;break;
case 0xE000:X6502_IRQEnd(FCEU_IQEXT);break;
}
// if(A<0x8000)
// printf("$%04x:$%02x, %d\n",A&0xFFFF,V,scanline);
if(A==0x5000)
{
master=V;
DoPRG();
DoCHR();
}
else if(A==0x5001)
{
chrm=V;
DoCHR();
}
else
switch(A&0xE000)
{
case 0x8000:setmirror(((V|(V>>7))&1)^1);break;
case 0xa000:cmd=V;cmdin=1;DoPRG();DoCHR();break;
case 0xC000:if(!cmdin) break;
regs[cmd&7]=V;
DoPRG();
DoCHR();
cmdin=0;
break;
}
}
static void UNL8237Reset(void)
{
int x;
for(x=0;x<8;x++) regs[x]=0;
master=chrm=cmd=cmdin=IRQCount=IRQa=0;
SetReadHandler(0x8000,0xFFFF,CartBR);
SetWriteHandler(0x5000,0xFFFF,UNL8237Write);
DoPRG();
DoCHR();
}
static void hooko(void)
{
if(IRQCount)
{
IRQCount--;
if(!IRQCount)
{
X6502_IRQBegin(FCEU_IQEXT);
//printf("IRQ: %d\n",scanline);
}
}
}
static void restoreo(int version)
{
DoPRG();
DoCHR();
}
void UNL8237_Init(CartInfo *info)
{
GameStateRestore=restoreo;
GameHBIRQHook=hooko;
info->Power=UNL8237Reset;
AddExState(regs, 8, 0, "REGS");
AddExState(&IRQCount, 4, 1, "IRQC");
AddExState(&IRQa, 1, 0, "IRQA");
AddExState(&master, 1, 0, "MAST");
AddExState(&chrm,1,0,"CHRM");
AddExState(&cmd,1,0,"CMD");
AddExState(&cmdin,1,0,"CMDI");
}