[fceu.git] / boards / 8157.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[]=
{
  {&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);
}
Commit	Line	Data
e2d0dd92	1	/* FCE Ultra - NES/Famicom Emulator
	2	*
	3	* Copyright notice for this file:
	4	* Copyright (C) 2005 CaH4e3
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program; if not, write to the Free Software
	18	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	19	*/
	20
	21	#include "mapinc.h"
	22
	23	static uint16 cmdreg;
	24	static uint8 invalid_data;
	25	static SFORMAT StateRegs[]=
	26	{
	27	{&cmdreg, 2, "CMDREG"},
	28	{0}
	29	};
	30
	31	static void Sync(void)
	32	{
	33	setprg16r((cmdreg&0x060)>>5,0x8000,(cmdreg&0x01C)>>2);
	34	setprg16r((cmdreg&0x060)>>5,0xC000,(cmdreg&0x200)?(~0):0);
	35	setmirror(((cmdreg&2)>>1)^1);
	36	}
	37
	38	static DECLFR(UNL8157Read)
	39	{
	40	if(invalid_data&&cmdreg&0x100)
	41	return 0xFF;
	42	else
	43	return CartBR(A);
	44	}
	45
	46	static DECLFW(UNL8157Write)
	47	{
	48	cmdreg=A;
	49	Sync();
	50	}
	51
	52	static void UNL8157Power(void)
	53	{
	54	setchr8(0);
	55	SetWriteHandler(0x8000,0xFFFF,UNL8157Write);
	56	SetReadHandler(0x8000,0xFFFF,UNL8157Read);
	57	cmdreg=0x200;
	58	invalid_data=1;
	59	Sync();
	60	}
	61
	62	static void UNL8157Reset(void)
	63	{
	64	cmdreg=0;
65	invalid_data^=1;
66	Sync();
67	}
68
69	static void UNL8157Restore(int version)
70	{
71	Sync();
72	}
73
74	void UNL8157_Init(CartInfo *info)
75	{
76	info->Power=UNL8157Power;
77	info->Reset=UNL8157Reset;
78	GameStateRestore=UNL8157Restore;
79	AddExState(&StateRegs, ~0, 0, 0);
80	}