map046.c
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/*
** 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.
**
**
** map046.c
**
** Mapper #46 (Pelican Game Station)
** Implementation by Firebug
** Mapper information courtesy of Kevin Horton
** $Id: map046.c,v 1.2 2001/04/27 14:37:11 neil Exp $
**
*/
#include <noftypes.h>
#include <nes_mmc.h>
#include <nes.h>
#include <libsnss.h>
#include <log.h>
static uint8 prg_low_bank;
static uint8 chr_low_bank;
static uint8 prg_high_bank;
static uint8 chr_high_bank;
/*************************************************/
/* Set banks from the combined register values */
/*************************************************/
static void map46_set_banks (void)
{
/* Set the PRG and CHR pages */
mmc_bankrom (32, 0x8000, (prg_high_bank << 1) | (prg_low_bank));
mmc_bankvrom (8, 0x0000, (chr_high_bank << 3) | (chr_low_bank));
/* Done */
return;
}
/*********************************************************/
/* Mapper #46: Pelican Game Station (aka Rumble Station) */
/*********************************************************/
static void map46_init (void)
{
/* High bank switch register is set to zero on reset */
prg_high_bank = 0x00;
chr_high_bank = 0x00;
map46_set_banks ();
/* Done */
return;
}
/******************************************/
/* Mapper #46 write handler ($6000-$FFFF) */
/******************************************/
static void map46_write (uint32 address, uint8 value)
{
/* $8000-$FFFF: D6-D4 = lower three bits of CHR bank */
/* D0 = low bit of PRG bank */
/* $6000-$7FFF: D7-D4 = high four bits of CHR bank */
/* D3-D0 = high four bits of PRG bank */
if (address & 0x8000)
{
prg_low_bank = value & 0x01;
chr_low_bank = (value >> 4) & 0x07;
map46_set_banks ();
}
else
{
prg_high_bank = value & 0x0F;
chr_high_bank = (value >> 4) & 0x0F;
map46_set_banks ();
}
/* Done */
return;
}
/****************************************************/
/* Shove extra mapper information into a SNSS block */
/****************************************************/
static void map46_setstate (SnssMapperBlock *state)
{
/* TODO: Store SNSS information */
UNUSED (state);
/* Done */
return;
}
/*****************************************************/
/* Pull extra mapper information out of a SNSS block */
/*****************************************************/
static void map46_getstate (SnssMapperBlock *state)
{
/* TODO: Retrieve SNSS information */
UNUSED (state);
/* Done */
return;
}
static map_memwrite map46_memwrite [] =
{
{ 0x6000, 0xFFFF, map46_write },
{ -1, -1, NULL }
};
mapintf_t map46_intf =
{
46, /* Mapper number */
"Pelican Game Station", /* Mapper name */
map46_init, /* Initialization routine */
NULL, /* VBlank callback */
NULL, /* HBlank callback */
map46_getstate, /* Get state (SNSS) */
map46_setstate, /* Set state (SNSS) */
NULL, /* Memory read structure */
map46_memwrite, /* Memory write structure */
NULL /* External sound device */
};
/*
** $Log: map046.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 19:23:05 firebug
** initial revision
**
**
*/