kopia lustrzana https://github.com/Jean-MarcHarvengt/MCUME
164 wiersze
3.7 KiB
C
Executable File
164 wiersze
3.7 KiB
C
Executable File
/*
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** Nofrendo (c) 1998-2000 Matthew Conte (matt@conte.com)
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**
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**
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** This program is free software; you can redistribute it and/or
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** modify it under the terms of version 2 of the GNU Library General
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** Public License as published by the Free Software Foundation.
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**
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** This program is distributed in the hope that it will be useful,
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** but WITHOUT ANY WARRANTY; without even the implied warranty of
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** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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** Library General Public License for more details. To obtain a
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** copy of the GNU Library General Public License, write to the Free
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** Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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**
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** Any permitted reproduction of these routines, in whole or in part,
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** must bear this legend.
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**
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**
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** map40.c
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**
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** mapper 40 interface
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** $Id: map040.c,v 1.2 2001/04/27 14:37:11 neil Exp $
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*/
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#include "noftypes.h"
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#include "nes_mmc.h"
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#include "nes.h"
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#include "libsnss.h"
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#include "log.h"
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#define MAP40_IRQ_PERIOD (4096 / 113.666666)
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static struct
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{
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int enabled, counter;
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} irq;
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/* mapper 40: SMB 2j (hack) */
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static void map40_init(void)
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{
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mmc_bankrom(8, 0x6000, 6);
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mmc_bankrom(8, 0x8000, 4);
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mmc_bankrom(8, 0xA000, 5);
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mmc_bankrom(8, 0xE000, 7);
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irq.enabled = false;
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irq.counter = (int) MAP40_IRQ_PERIOD;
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}
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static void map40_hblank(int vblank)
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{
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UNUSED(vblank);
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if (irq.enabled && irq.counter)
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{
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irq.counter--;
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if (0 == irq.counter)
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{
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nes_irq();
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irq.enabled = false;
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}
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}
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}
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static void map40_write(uint32 address, uint8 value)
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{
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int range = (address >> 13) - 4;
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switch (range)
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{
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case 0: /* 0x8000-0x9FFF */
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irq.enabled = false;
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irq.counter = (int) MAP40_IRQ_PERIOD;
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break;
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case 1: /* 0xA000-0xBFFF */
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irq.enabled = true;
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break;
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case 3: /* 0xE000-0xFFFF */
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mmc_bankrom(8, 0xC000, value & 7);
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break;
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default:
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break;
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}
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}
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static void map40_getstate(SnssMapperBlock *state)
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{
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state->extraData.mapper40.irqCounter = irq.counter;
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state->extraData.mapper40.irqCounterEnabled = irq.enabled;
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}
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static void map40_setstate(SnssMapperBlock *state)
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{
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irq.counter = state->extraData.mapper40.irqCounter;
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irq.enabled = state->extraData.mapper40.irqCounterEnabled;
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}
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static const map_memwrite map40_memwrite[] =
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{
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{ 0x8000, 0xFFFF, map40_write },
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{ -1, -1, NULL }
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};
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const mapintf_t map40_intf =
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{
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40, /* mapper number */
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"SMB 2j (pirate)", /* mapper name */
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map40_init, /* init routine */
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NULL, /* vblank callback */
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map40_hblank, /* hblank callback */
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map40_getstate, /* get state (snss) */
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map40_setstate, /* set state (snss) */
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NULL, /* memory read structure */
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map40_memwrite, /* memory write structure */
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NULL /* external sound device */
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};
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/*
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** $Log: map040.c,v $
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** Revision 1.2 2001/04/27 14:37:11 neil
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** wheeee
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**
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** Revision 1.1 2001/04/27 12:54:40 neil
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** blah
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**
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** Revision 1.1.1.1 2001/04/27 07:03:54 neil
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** initial
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**
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** Revision 1.1 2000/10/24 12:19:33 matt
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** changed directory structure
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**
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** Revision 1.9 2000/10/23 15:53:27 matt
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** suppressed warnings
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**
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** Revision 1.8 2000/10/22 19:17:46 matt
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** mapper cleanups galore
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**
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** Revision 1.7 2000/10/21 19:33:38 matt
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** many more cleanups
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**
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** Revision 1.6 2000/10/10 13:58:17 matt
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** stroustrup squeezing his way in the door
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**
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** Revision 1.5 2000/08/16 02:50:11 matt
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** random mapper cleanups
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**
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** Revision 1.4 2000/07/15 23:52:19 matt
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** rounded out a bunch more mapper interfaces
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**
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** Revision 1.3 2000/07/10 13:51:25 matt
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** using generic nes_irq() routine now
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**
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** Revision 1.2 2000/07/06 02:48:43 matt
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** clearly labelled structure members
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**
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** Revision 1.1 2000/07/05 05:05:18 matt
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** initial revision
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**
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*/
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