MCUME/MCUME_teensy/teensynofrendo/map018.c

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6.2 KiB
C
Executable File

/*
** Nofrendo (c) 1998-2000 Matthew Conte (matt@conte.com)
**
**
** This program is free software; you can redistribute it and/or
** modify it under the terms of version 2 of the GNU Library General
** Public License as published by the Free Software Foundation.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
** Library General Public License for more details. To obtain a
** copy of the GNU Library General Public License, write to the Free
** Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**
** Any permitted reproduction of these routines, in whole or in part,
** must bear this legend.
**
**
** map18.c
**
** mapper 18 interface
** $Id: map018.c,v 1.2 2001/04/27 14:37:11 neil Exp $
*/
#include "noftypes.h"
#include "nes_mmc.h"
#include "nes_ppu.h"
/* mapper 18: Jaleco SS8806 */
#define VRC_PBANK(bank, value, high) \
do { \
if ((high)) \
highprgnybbles[(bank)] = (value) & 0x0F; \
else \
lowprgnybbles[(bank)] = (value) & 0x0F; \
mmc_bankrom(8, 0x8000 + ((bank) << 13), (highprgnybbles[(bank)] << 4)+lowprgnybbles[(bank)]); \
} while (0)
#define VRC_VBANK(bank, value, high) \
{ \
if ((high)) \
highnybbles[(bank)] = (value) & 0x0F; \
else \
lownybbles[(bank)] = (value) & 0x0F; \
mmc_bankvrom(1, (bank) << 10, (highnybbles[(bank)] << 4)+lownybbles[(bank)]); \
}
static struct
{
int counter, enabled;
uint8 nybbles[4];
int clockticks;
} irq;
static void map18_init(void)
{
irq.counter = irq.enabled = 0;
}
static uint8 lownybbles[8];
static uint8 highnybbles[8];
static uint8 lowprgnybbles[3];
static uint8 highprgnybbles[3];
static void map18_write(uint32 address, uint8 value)
{
switch (address)
{
case 0x8000: VRC_PBANK(0, value, 0); break;
case 0x8001: VRC_PBANK(0, value, 1); break;
case 0x8002: VRC_PBANK(1, value, 0); break;
case 0x8003: VRC_PBANK(1, value, 1); break;
case 0x9000: VRC_PBANK(2, value, 0); break;
case 0x9001: VRC_PBANK(2, value, 1); break;
case 0xA000: VRC_VBANK(0, value, 0); break;
case 0xA001: VRC_VBANK(0, value, 1); break;
case 0xA002: VRC_VBANK(1, value, 0); break;
case 0xA003: VRC_VBANK(1, value, 1); break;
case 0xB000: VRC_VBANK(2, value, 0); break;
case 0xB001: VRC_VBANK(2, value, 1); break;
case 0xB002: VRC_VBANK(3, value, 0); break;
case 0xB003: VRC_VBANK(3, value, 1); break;
case 0xC000: VRC_VBANK(4, value, 0); break;
case 0xC001: VRC_VBANK(4, value, 1); break;
case 0xC002: VRC_VBANK(5, value, 0); break;
case 0xC003: VRC_VBANK(5, value, 1); break;
case 0xD000: VRC_VBANK(6, value, 0); break;
case 0xD001: VRC_VBANK(6, value, 1); break;
case 0xD002: VRC_VBANK(7, value, 0); break;
case 0xD003: VRC_VBANK(7, value, 1); break;
case 0xE000:
irq.nybbles[0]=value&0x0F;
irq.clockticks= (irq.nybbles[0]) | (irq.nybbles[1]<<4) |
(irq.nybbles[2]<<8) | (irq.nybbles[3]<<12);
irq.counter=(uint8)(irq.clockticks/114);
if(irq.counter>15) irq.counter-=16;
break;
case 0xE001:
irq.nybbles[1]=value&0x0F;
irq.clockticks= (irq.nybbles[0]) | (irq.nybbles[1]<<4) |
(irq.nybbles[2]<<8) | (irq.nybbles[3]<<12);
irq.counter=(uint8)(irq.clockticks/114);
if(irq.counter>15) irq.counter-=16;
break;
case 0xE002:
irq.nybbles[2]=value&0x0F;
irq.clockticks= (irq.nybbles[0]) | (irq.nybbles[1]<<4) |
(irq.nybbles[2]<<8) | (irq.nybbles[3]<<12);
irq.counter=(uint8)(irq.clockticks/114);
if(irq.counter>15) irq.counter-=16;
break;
case 0xE003:
irq.nybbles[3]=value&0x0F;
irq.clockticks= (irq.nybbles[0]) | (irq.nybbles[1]<<4) |
(irq.nybbles[2]<<8) | (irq.nybbles[3]<<12);
irq.counter=(uint8)(irq.clockticks/114);
if(irq.counter>15) irq.counter-=16;
break;
case 0xF000:
if(value&0x01) irq.enabled=true;
break;
case 0xF001:
irq.enabled=value&0x01;
break;
case 0xF002:
switch(value&0x03)
{
case 0: ppu_mirror(0, 0, 1, 1); break;
case 1: ppu_mirror(0, 1, 0, 1); break;
case 2: ppu_mirror(1,1,1,1);break;
case 3: ppu_mirror(1,1,1,1);break; // should this be zero?
default: break;
}
break;
default:
break;
}
}
static const map_memwrite map18_memwrite[] =
{
{ 0x8000, 0xFFFF, map18_write },
{ -1, -1, NULL }
};
static void map18_getstate(SnssMapperBlock *state)
{
state->extraData.mapper18.irqCounterLowByte = irq.counter & 0xFF;
state->extraData.mapper18.irqCounterHighByte = irq.counter >> 8;
state->extraData.mapper18.irqCounterEnabled = irq.enabled;
}
static void map18_setstate(SnssMapperBlock *state)
{
irq.counter = (state->extraData.mapper18.irqCounterHighByte << 8)
| state->extraData.mapper18.irqCounterLowByte;
irq.enabled = state->extraData.mapper18.irqCounterEnabled;
}
const mapintf_t map18_intf =
{
18, /* mapper number */
"Jaleco SS8806", /* mapper name */
map18_init, /* init routine */
NULL, /* vblank callback */
NULL, /* hblank callback */
map18_getstate, /* get state (snss) */
map18_setstate, /* set state (snss) */
NULL, /* memory read structure */
map18_memwrite, /* memory write structure */
NULL /* external sound device */
};
/*
** $Log: map018.c,v $
** Revision 1.2 2001/04/27 14:37:11 neil
** wheeee
**
** Revision 1.1 2001/04/27 12:54:40 neil
** blah
**
** Revision 1.1.1.1 2001/04/27 07:03:54 neil
** initial
**
** Revision 1.1 2000/10/24 12:19:33 matt
** changed directory structure
**
** Revision 1.8 2000/10/22 19:17:46 matt
** mapper cleanups galore
**
** Revision 1.7 2000/10/22 15:03:13 matt
** simplified mirroring
**
** Revision 1.6 2000/10/21 19:33:38 matt
** many more cleanups
**
** Revision 1.5 2000/10/10 13:58:17 matt
** stroustrup squeezing his way in the door
**
** Revision 1.4 2000/07/15 23:52:19 matt
** rounded out a bunch more mapper interfaces
**
** Revision 1.3 2000/07/10 05:29:03 matt
** cleaned up some mirroring issues
**
** Revision 1.2 2000/07/06 02:48:42 matt
** clearly labelled structure members
**
** Revision 1.1 2000/07/06 01:01:56 matt
** initial revision
**
*/