kopia lustrzana https://github.com/Jean-MarcHarvengt/MCUME
168 wiersze
4.7 KiB
C
168 wiersze
4.7 KiB
C
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/*
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** Nofrendo (c) 1998-2000 Matthew Conte (matt@conte.com)
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**
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**
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** This program is free software; you can redistribute it and/or
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** modify it under the terms of version 2 of the GNU Library General
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** Public License as published by the Free Software Foundation.
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**
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** This program is distributed in the hope that it will be useful,
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** but WITHOUT ANY WARRANTY; without even the implied warranty of
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** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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** Library General Public License for more details. To obtain a
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** copy of the GNU Library General Public License, write to the Free
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** Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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**
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** Any permitted reproduction of these routines, in whole or in part,
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** must bear this legend.
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**
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**
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** map041.c
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**
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** Mapper #41 (Caltron 6 in 1)
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** Implementation by Firebug
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** Mapper information courtesy of Kevin Horton
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** $Id: map041.c,v 1.2 2001/04/27 14:37:11 neil Exp $
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**
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*/
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#include "noftypes.h"
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#include "nes_mmc.h"
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#include "nes.h"
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#include "libsnss.h"
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#include "log.h"
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static uint8 register_low;
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static uint8 register_high;
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/*****************************************************/
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/* Set 8K CHR bank from the combined register values */
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/*****************************************************/
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static void map41_set_chr (void)
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{
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/* Set the CHR bank from the appropriate register bits */
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mmc_bankvrom (8, 0x0000, ((register_low >> 1) & 0x0C) | (register_high));
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/* Done */
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return;
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}
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/******************************/
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/* Mapper #41: Caltron 6 in 1 */
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/******************************/
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static void map41_init (void)
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{
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/* Both registers set to zero at power on */
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/* TODO: Registers should also be cleared on a soft reset */
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register_low = 0x00;
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register_high = 0x00;
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mmc_bankrom (32, 0x8000, 0x00);
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map41_set_chr ();
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/* Done */
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return;
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}
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/******************************************/
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/* Mapper #41 write handler ($6000-$67FF) */
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/******************************************/
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static void map41_low_write (uint32 address, uint8 value)
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{
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/* Within this range the value written is irrelevant */
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UNUSED (value);
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/* $6000-$67FF: A5 = mirroring (1=horizontal, 0=vertical) */
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/* A4-A3 = high two bits of 8K CHR bank */
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/* A2 = register 1 enable (0=disabled, 1=enabled) */
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/* A2-A0 = 32K PRG bank */
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register_low = (uint8) (address & 0x3F);
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mmc_bankrom (32, 0x8000, register_low & 0x07);
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map41_set_chr ();
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if (register_low & 0x20) ppu_mirror(0, 0, 1, 1); /* horizontal */
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else ppu_mirror(0, 1, 0, 1); /* vertical */
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/* Done */
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return;
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}
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/******************************************/
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/* Mapper #41 write handler ($8000-$FFFF) */
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/******************************************/
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static void map41_high_write (uint32 address, uint8 value)
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{
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/* Address doesn't matter within this range */
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UNUSED (address);
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/* $8000-$FFFF: D1-D0 = low two bits of 8K CHR bank */
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if (register_low & 0x04)
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{
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register_high = value & 0x03;
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map41_set_chr ();
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}
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/* Done */
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return;
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}
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/****************************************************/
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/* Shove extra mapper information into a SNSS block */
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/****************************************************/
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static void map41_setstate (SnssMapperBlock *state)
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{
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/* TODO: Store SNSS information */
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UNUSED (state);
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/* Done */
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return;
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}
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/*****************************************************/
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/* Pull extra mapper information out of a SNSS block */
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/*****************************************************/
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static void map41_getstate (SnssMapperBlock *state)
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{
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/* TODO: Retrieve SNSS information */
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UNUSED (state);
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/* Done */
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return;
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}
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static const map_memwrite map41_memwrite [] =
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{
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{ 0x6000, 0x67FF, map41_low_write },
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{ 0x8000, 0xFFFF, map41_high_write },
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{ -1, -1, NULL }
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};
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const mapintf_t map41_intf =
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{
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41, /* Mapper number */
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"Caltron 6 in 1", /* Mapper name */
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map41_init, /* Initialization routine */
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NULL, /* VBlank callback */
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NULL, /* HBlank callback */
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map41_getstate, /* Get state (SNSS) */
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map41_setstate, /* Set state (SNSS) */
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NULL, /* Memory read structure */
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map41_memwrite, /* Memory write structure */
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NULL /* External sound device */
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};
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/*
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** $Log: map041.c,v $
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** Revision 1.2 2001/04/27 14:37:11 neil
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** wheeee
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**
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** Revision 1.1 2001/04/27 12:54:40 neil
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** blah
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**
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** Revision 1.1 2001/04/27 10:57:41 neil
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** wheee
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**
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** Revision 1.1 2000/12/30 00:33:15 firebug
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** initial revision
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**
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**
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*/
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