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  ** map19.c
 21  **
 22  ** mapper 19 interface
 23  ** $Id: map019.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  /* TODO: shouldn't there be an h-blank IRQ handler??? */
 31  
 32  /* Special mirroring macro for mapper 19 */
 33  #define N_BANK1(table, value) \
 34  { \
 35     if ((value) < 0xE0) \
 36        ppu_setpage(1, (table) + 8, &mmc_getinfo()->vrom[((value) % (mmc_getinfo()->vrom_banks * 8)) << 10] - (0x2000 + ((table) << 10))); \
 37     else \
 38        ppu_setpage(1, (table) + 8, &mmc_getinfo()->vram[((value) & 7) << 10] - (0x2000 + ((table) << 10))); \
 39     ppu_mirrorhipages(); \
 40  }
 41  
 42  static struct
 43  {
 44     int counter, enabled;
 45  } irq;
 46  
 47  static void map19_init(void)
 48  {
 49     irq.counter = irq.enabled = 0;
 50  }
 51  
 52  /* mapper 19: Namcot 106 */
 53  static void map19_write(uint32 address, uint8 value)
 54  {
 55     int reg = address >> 11;
 56     switch (reg)
 57     {
 58     case 0xA:
 59        irq.counter &= ~0xFF;
 60        irq.counter |= value;
 61        break;
 62     
 63     case 0xB:
 64        irq.counter = ((value & 0x7F) << 8) | (irq.counter & 0xFF);
 65        irq.enabled = (value & 0x80) ? true : false;
 66        break;
 67  
 68     case 0x10:
 69     case 0x11:
 70     case 0x12:
 71     case 0x13:
 72     case 0x14:
 73     case 0x15:
 74     case 0x16:
 75     case 0x17:
 76        mmc_bankvrom(1, (reg & 7) << 10, value);
 77        break;
 78  
 79     case 0x18:
 80     case 0x19:
 81     case 0x1A:
 82     case 0x1B:
 83        N_BANK1(reg & 3, value);
 84        break;
 85  
 86     case 0x1C:
 87        mmc_bankrom(8, 0x8000, value);
 88        break;
 89  
 90     case 0x1D:
 91        mmc_bankrom(8, 0xA000, value);
 92        break;
 93     
 94     case 0x1E:
 95        mmc_bankrom(8, 0xC000, value);
 96        break;
 97     
 98     default:
 99        break;
100     }
101  }
102  
103  static void map19_getstate(SnssMapperBlock *state)
104  {
105     state->extraData.mapper19.irqCounterLowByte = irq.counter & 0xFF;
106     state->extraData.mapper19.irqCounterHighByte = irq.counter >> 8;
107     state->extraData.mapper19.irqCounterEnabled = irq.enabled;
108  }
109  
110  static void map19_setstate(SnssMapperBlock *state)
111  {
112     irq.counter = (state->extraData.mapper19.irqCounterHighByte << 8)
113                         | state->extraData.mapper19.irqCounterLowByte;
114     irq.enabled = state->extraData.mapper19.irqCounterEnabled;
115  }
116  
117  static const map_memwrite map19_memwrite[] =
118  {
119     { 0x5000, 0x5FFF, map19_write },
120     { 0x8000, 0xFFFF, map19_write },
121     {     -1,     -1, NULL }
122  };
123  
124  const mapintf_t map19_intf =
125  {
126     19, /* mapper number */
127     "Namcot 106", /* mapper name */
128     map19_init, /* init routine */
129     NULL, /* vblank callback */
130     NULL, /* hblank callback */
131     map19_getstate, /* get state (snss) */
132     map19_setstate, /* set state (snss) */
133     NULL, /* memory read structure */
134     map19_memwrite, /* memory write structure */
135     NULL /* external sound device */
136  };
137  
138  /*
139  ** $Log: map019.c,v $
140  ** Revision 1.2  2001/04/27 14:37:11  neil
141  ** wheeee
142  **
143  ** Revision 1.1  2001/04/27 12:54:40  neil
144  ** blah
145  **
146  ** Revision 1.1.1.1  2001/04/27 07:03:54  neil
147  ** initial
148  **
149  ** Revision 1.1  2000/10/24 12:19:33  matt
150  ** changed directory structure
151  **
152  ** Revision 1.6  2000/10/22 19:17:46  matt
153  ** mapper cleanups galore
154  **
155  ** Revision 1.5  2000/10/21 19:33:38  matt
156  ** many more cleanups
157  **
158  ** Revision 1.4  2000/10/10 13:58:17  matt
159  ** stroustrup squeezing his way in the door
160  **
161  ** Revision 1.3  2000/07/15 23:52:20  matt
162  ** rounded out a bunch more mapper interfaces
163  **
164  ** Revision 1.2  2000/07/06 02:48:43  matt
165  ** clearly labelled structure members
166  **
167  ** Revision 1.1  2000/07/06 01:01:56  matt
168  ** initial revision
169  **
170  */