kopia lustrzana https://github.com/Jean-MarcHarvengt/MCUME
168 wiersze
4.7 KiB
C
Executable File
168 wiersze
4.7 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.
|
|
**
|
|
**
|
|
** map041.c
|
|
**
|
|
** Mapper #41 (Caltron 6 in 1)
|
|
** Implementation by Firebug
|
|
** Mapper information courtesy of Kevin Horton
|
|
** $Id: map041.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 register_low;
|
|
static uint8 register_high;
|
|
|
|
/*****************************************************/
|
|
/* Set 8K CHR bank from the combined register values */
|
|
/*****************************************************/
|
|
static void map41_set_chr (void)
|
|
{
|
|
/* Set the CHR bank from the appropriate register bits */
|
|
mmc_bankvrom (8, 0x0000, ((register_low >> 1) & 0x0C) | (register_high));
|
|
|
|
/* Done */
|
|
return;
|
|
}
|
|
|
|
/******************************/
|
|
/* Mapper #41: Caltron 6 in 1 */
|
|
/******************************/
|
|
static void map41_init (void)
|
|
{
|
|
/* Both registers set to zero at power on */
|
|
/* TODO: Registers should also be cleared on a soft reset */
|
|
register_low = 0x00;
|
|
register_high = 0x00;
|
|
mmc_bankrom (32, 0x8000, 0x00);
|
|
map41_set_chr ();
|
|
|
|
/* Done */
|
|
return;
|
|
}
|
|
|
|
/******************************************/
|
|
/* Mapper #41 write handler ($6000-$67FF) */
|
|
/******************************************/
|
|
static void map41_low_write (uint32 address, uint8 value)
|
|
{
|
|
/* Within this range the value written is irrelevant */
|
|
UNUSED (value);
|
|
|
|
/* $6000-$67FF: A5 = mirroring (1=horizontal, 0=vertical) */
|
|
/* A4-A3 = high two bits of 8K CHR bank */
|
|
/* A2 = register 1 enable (0=disabled, 1=enabled) */
|
|
/* A2-A0 = 32K PRG bank */
|
|
register_low = (uint8) (address & 0x3F);
|
|
mmc_bankrom (32, 0x8000, register_low & 0x07);
|
|
map41_set_chr ();
|
|
if (register_low & 0x20) ppu_mirror(0, 0, 1, 1); /* horizontal */
|
|
else ppu_mirror(0, 1, 0, 1); /* vertical */
|
|
|
|
/* Done */
|
|
return;
|
|
}
|
|
|
|
/******************************************/
|
|
/* Mapper #41 write handler ($8000-$FFFF) */
|
|
/******************************************/
|
|
static void map41_high_write (uint32 address, uint8 value)
|
|
{
|
|
/* Address doesn't matter within this range */
|
|
UNUSED (address);
|
|
|
|
/* $8000-$FFFF: D1-D0 = low two bits of 8K CHR bank */
|
|
if (register_low & 0x04)
|
|
{
|
|
register_high = value & 0x03;
|
|
map41_set_chr ();
|
|
}
|
|
|
|
/* Done */
|
|
return;
|
|
}
|
|
|
|
/****************************************************/
|
|
/* Shove extra mapper information into a SNSS block */
|
|
/****************************************************/
|
|
static void map41_setstate (SnssMapperBlock *state)
|
|
{
|
|
/* TODO: Store SNSS information */
|
|
UNUSED (state);
|
|
|
|
/* Done */
|
|
return;
|
|
}
|
|
|
|
/*****************************************************/
|
|
/* Pull extra mapper information out of a SNSS block */
|
|
/*****************************************************/
|
|
static void map41_getstate (SnssMapperBlock *state)
|
|
{
|
|
/* TODO: Retrieve SNSS information */
|
|
UNUSED (state);
|
|
|
|
/* Done */
|
|
return;
|
|
}
|
|
|
|
static const map_memwrite map41_memwrite [] =
|
|
{
|
|
{ 0x6000, 0x67FF, map41_low_write },
|
|
{ 0x8000, 0xFFFF, map41_high_write },
|
|
{ -1, -1, NULL }
|
|
};
|
|
|
|
const mapintf_t map41_intf =
|
|
{
|
|
41, /* Mapper number */
|
|
"Caltron 6 in 1", /* Mapper name */
|
|
map41_init, /* Initialization routine */
|
|
NULL, /* VBlank callback */
|
|
NULL, /* HBlank callback */
|
|
map41_getstate, /* Get state (SNSS) */
|
|
map41_setstate, /* Set state (SNSS) */
|
|
NULL, /* Memory read structure */
|
|
map41_memwrite, /* Memory write structure */
|
|
NULL /* External sound device */
|
|
};
|
|
|
|
/*
|
|
** $Log: map041.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 2000/12/30 00:33:15 firebug
|
|
** initial revision
|
|
**
|
|
**
|
|
*/
|