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  ** map087.c
21  **
22  ** Mapper #87 (16K VROM switch)
23  ** Implementation by Firebug
24  ** $Id: map087.c,v 1.2 2001/04/27 14:37:11 neil Exp $
25  **
26  */
27  
28  #include "noftypes.h"
29  #include "nes_mmc.h"
30  #include "nes.h"
31  #include "libsnss.h"
32  #include "log.h"
33  
34  /******************************************/
35  /* Mapper #87 write handler ($6000-$7FFF) */
36  /******************************************/
37  static void map87_write (uint32 address, uint8 value)
38  {
39    /* Within range, address written to is irrelevant */
40    UNUSED (address);
41  
42    /* Very simple: 8K CHR page is selected by D1 */
43    if (value & 0x02) mmc_bankvrom (8, 0x0000, 0x01);
44    else              mmc_bankvrom (8, 0x0000, 0x00);
45  
46    /* Done */
47    return;
48  }
49  
50  static const map_memwrite map87_memwrite [] =
51  {
52     { 0x6000, 0x7FFF, map87_write },
53     {     -1,     -1, NULL }
54  };
55  
56  const mapintf_t map87_intf =
57  {
58     87,                               /* Mapper number */
59     "16K VROM switch",                /* Mapper name */
60     NULL,                             /* Initialization routine */
61     NULL,                             /* VBlank callback */
62     NULL,                             /* HBlank callback */
63     NULL,                             /* Get state (SNSS) */
64     NULL,                             /* Set state (SNSS) */
65     NULL,                             /* Memory read structure */
66     map87_memwrite,                   /* Memory write structure */
67     NULL                              /* External sound device */
68  };
69  
70  /*
71  ** $Log: map087.c,v $
72  ** Revision 1.2  2001/04/27 14:37:11  neil
73  ** wheeee
74  **
75  ** Revision 1.1  2001/04/27 12:54:40  neil
76  ** blah
77  **
78  ** Revision 1.1  2001/04/27 10:57:41  neil
79  ** wheee
80  **
81  ** Revision 1.1  2000/12/30 06:34:44  firebug
82  ** Initial revision
83  **
84  **
85  */