1  /*
  2  ** Nofrendo (c) 1998-2000 Matthew Conte (matt@conte.com)
  3  **
  4  **
  5  ** This program is free software; you can redistribute it and/or
  6  ** modify it under the terms of version 2 of the GNU Library General 
  7  ** Public License as published by the Free Software Foundation.
  8  **
  9  ** This program is distributed in the hope that it will be useful, 
 10  ** but WITHOUT ANY WARRANTY; without even the implied warranty of
 11  ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU 
 12  ** Library General Public License for more details.  To obtain a 
 13  ** copy of the GNU Library General Public License, write to the Free 
 14  ** Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 15  **
 16  ** Any permitted reproduction of these routines, in whole or in part,
 17  ** must bear this legend.
 18  **
 19  **
 20  ** map229.c
 21  **
 22  ** Mapper #229 (31 in 1)
 23  ** Implementation by Firebug
 24  ** Mapper information courtesy of Mark Knibbs
 25  ** $Id: map229.c,v 1.2 2001/04/27 14:37:11 neil Exp $
 26  **
 27  */
 28  
 29  #include "noftypes.h"
 30  #include "nes_mmc.h"
 31  #include "nes.h"
 32  #include "libsnss.h"
 33  #include "log.h"
 34  
 35  /************************/
 36  /* Mapper #229: 31 in 1 */
 37  /************************/
 38  static void map229_init (void)
 39  {
 40    /* On reset, PRG is set to first 32K and CHR to first 8K */
 41    mmc_bankrom (32, 0x8000, 0x00);
 42    mmc_bankvrom (8, 0x0000, 0x00);
 43  
 44    /* Done */
 45    return;
 46  }
 47  
 48  /*******************************************/
 49  /* Mapper #229 write handler ($8000-$FFFF) */
 50  /*******************************************/
 51  static void map229_write (uint32 address, uint8 value)
 52  {
 53    /* Value written is irrelevant */
 54    UNUSED (value);
 55  
 56    /* A4-A0 sets 8K CHR page */
 57    mmc_bankvrom (8, 0x0000, (uint8) (address & 0x1F));
 58  
 59    /* If A4-A1 are all low then select the first 32K,     */
 60    /* otherwise select a 16K bank at both $8000 and $C000 */
 61    if ((address & 0x1E) == 0x00)
 62    {
 63      mmc_bankrom (32, 0x8000, 0x00);
 64    }
 65    else
 66    {
 67      mmc_bankrom (16, 0x8000, (uint8) (address & 0x1F));
 68      mmc_bankrom (16, 0xC000, (uint8) (address & 0x1F));
 69    }
 70  
 71    /* A5: mirroring (low = vertical, high = horizontal) */
 72    if (address & 0x20) ppu_mirror(0, 0, 1, 1);
 73    else                ppu_mirror(0, 1, 0, 1);
 74  
 75    /* Done */
 76    return;
 77  }
 78  
 79  static const map_memwrite map229_memwrite [] =
 80  {
 81     { 0x8000, 0xFFFF, map229_write },
 82     {     -1,     -1, NULL }
 83  };
 84  
 85  const mapintf_t map229_intf =
 86  {
 87     229,                              /* Mapper number */
 88     "31 in 1 (bootleg)",              /* Mapper name */
 89     map229_init,                      /* Initialization routine */
 90     NULL,                             /* VBlank callback */
 91     NULL,                             /* HBlank callback */
 92     NULL,                             /* Get state (SNSS) */
 93     NULL,                             /* Set state (SNSS) */
 94     NULL,                             /* Memory read structure */
 95     map229_memwrite,                  /* Memory write structure */
 96     NULL                              /* External sound device */
 97  };
 98  
 99  /*
100  ** $Log: map229.c,v $
101  ** Revision 1.2  2001/04/27 14:37:11  neil
102  ** wheeee
103  **
104  ** Revision 1.1  2001/04/27 12:54:40  neil
105  ** blah
106  **
107  ** Revision 1.1  2001/04/27 10:57:41  neil
108  ** wheee
109  **
110  ** Revision 1.1  2000/12/30 06:34:31  firebug
111  ** Initial revision
112  **
113  **
114  */