MCUME/MCUME_teensy/teensynofrendo/map160.c

141 wiersze
3.1 KiB
C
Executable File

/*
** Nofrendo (c) 1998-2000 Matthew Conte (matt@conte.com)
**
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of version 2 of the GNU Library General
** Public License as published by the Free Software Foundation.
**
** 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
** Library General Public License for more details. To obtain a
** copy of the GNU Library General Public License, write to the Free
** Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**
** Any permitted reproduction of these routines, in whole or in part,
** must bear this legend.
**
**
** map160.c
**
** mapper 160 interface
** $Id: map160.c,v 1.2 2001/04/27 14:37:11 neil Exp $
*/
#include "noftypes.h"
#include "nes_mmc.h"
#include "nes_ppu.h"
#include "nes.h"
static struct
{
bool enabled, expired;
int counter;
int latch_c005, latch_c003;
} irq;
static void map160_write(uint32 address, uint8 value)
{
if (address >= 0x8000 && address <= 0x8003)
{
mmc_bankrom(8, 0x8000 + 0x2000 * (address & 3), value);
}
else if (address >= 0x9000 && address <= 0x9007)
{
mmc_bankvrom(1, 0x400 * (address & 7), value);
}
else if (0xC002 == address)
{
irq.enabled = false;
irq.latch_c005 = irq.latch_c003;
}
else if (0xC003 == address)
{
if (false == irq.expired)
{
irq.counter = value;
}
else
{
irq.expired = false;
irq.enabled = true;
irq.counter = irq.latch_c005;
}
}
else if (0xC005 == address)
{
irq.latch_c005 = value;
irq.counter = value;
}
#ifdef NOFRENDO_DEBUG
else
{
log_printf("mapper 160: untrapped write $%02X to $%04X\n", value, address);
}
#endif /* NOFRENDO_DEBUG */
}
static void map160_hblank(int vblank)
{
if (!vblank)
{
if (ppu_enabled() && irq.enabled)
{
if (0 == irq.counter && false == irq.expired)
{
irq.expired = true;
nes_irq();
}
else
{
irq.counter--;
}
}
}
}
static void map160_init(void)
{
irq.enabled = false;
irq.expired = false;
irq.counter = 0;
irq.latch_c003 = irq.latch_c005 = 0;
}
static const map_memwrite map160_memwrite[] =
{
{ 0x8000, 0xFFFF, map160_write },
{ -1, -1, NULL }
};
const mapintf_t map160_intf =
{
160, /* mapper number */
"Aladdin (pirate)", /* mapper name */
map160_init, /* init routine */
NULL, /* vblank callback */
map160_hblank, /* hblank callback */
NULL, /* get state (snss) */
NULL, /* set state (snss) */
NULL, /* memory read structure */
map160_memwrite, /* memory write structure */
NULL /* external sound device */
};
/*
** $Log: map160.c,v $
** Revision 1.2 2001/04/27 14:37:11 neil
** wheeee
**
** Revision 1.1 2001/04/27 12:54:40 neil
** blah
**
** Revision 1.1 2001/04/27 10:57:41 neil
** wheee
**
** Revision 1.1 2000/12/27 04:24:46 matt
** initial revision
**
*/