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  ** map65.c
 21  **
 22  ** mapper 65 interface
 23  ** $Id: map065.c,v 1.2 2001/04/27 14:37:11 neil Exp $
 24  */
 25  
 26  #include "noftypes.h"
 27  #include "nes_mmc.h"
 28  #include "nes_ppu.h"
 29  
 30  static struct
 31  {
 32     int counter;
 33     bool enabled;
 34     int cycles;
 35     uint8 low, high;
 36  } irq;
 37  
 38  static void map65_init(void)
 39  {
 40     irq.counter = 0;
 41     irq.enabled = false;
 42     irq.low = irq.high = 0;
 43     irq.cycles = 0;
 44  }
 45  
 46  /* TODO: shouldn't there be some kind of HBlank callback??? */
 47  
 48  /* mapper 65: Irem H-3001*/
 49  static void map65_write(uint32 address, uint8 value)
 50  {
 51     int range = address & 0xF000;
 52     int reg = address & 7;
 53  
 54     switch (range)
 55     {
 56     case 0x8000:
 57     case 0xA000:
 58     case 0xC000:
 59        mmc_bankrom(8, range, value);
 60        break;
 61  
 62     case 0xB000:
 63        mmc_bankvrom(1, reg << 10, value);
 64        break;
 65  
 66     case 0x9000:
 67        switch (reg)
 68        {
 69        case 4:
 70           irq.enabled = (value & 0x01) ? false : true;
 71           break;
 72  
 73        case 5:
 74           irq.high = value;
 75           irq.cycles = (irq.high << 8) | irq.low;
 76           irq.counter = (uint8)(irq.cycles / 128);
 77           break;
 78  
 79        case 6:
 80           irq.low = value;
 81           irq.cycles = (irq.high << 8) | irq.low;
 82           irq.counter = (uint8)(irq.cycles / 128);
 83           break;
 84  
 85        default:
 86           break;
 87        }
 88        break;
 89  
 90     default:
 91        break;
 92     }
 93  }
 94  
 95  static const map_memwrite map65_memwrite[] =
 96  {
 97     { 0x8000, 0xFFFF, map65_write },
 98     {     -1,     -1, NULL }
 99  };
100  
101  const mapintf_t map65_intf =
102  {
103     65, /* mapper number */
104     "Irem H-3001", /* mapper name */
105     map65_init, /* init routine */
106     NULL, /* vblank callback */
107     NULL, /* hblank callback */
108     NULL, /* get state (snss) */
109     NULL, /* set state (snss) */
110     NULL, /* memory read structure */
111     map65_memwrite, /* memory write structure */
112     NULL /* external sound device */
113  };
114  
115  /*
116  ** $Log: map065.c,v $
117  ** Revision 1.2  2001/04/27 14:37:11  neil
118  ** wheeee
119  **
120  ** Revision 1.1  2001/04/27 12:54:40  neil
121  ** blah
122  **
123  ** Revision 1.1.1.1  2001/04/27 07:03:54  neil
124  ** initial
125  **
126  ** Revision 1.1  2000/10/24 12:19:33  matt
127  ** changed directory structure
128  **
129  ** Revision 1.5  2000/10/22 19:17:46  matt
130  ** mapper cleanups galore
131  **
132  ** Revision 1.4  2000/10/21 19:33:38  matt
133  ** many more cleanups
134  **
135  ** Revision 1.3  2000/10/10 13:58:17  matt
136  ** stroustrup squeezing his way in the door
137  **
138  ** Revision 1.2  2000/07/06 02:48:43  matt
139  ** clearly labelled structure members
140  **
141  ** Revision 1.1  2000/07/06 01:01:56  matt
142  ** initial revision
143  **
144  */