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Genesis-Plus-GX/source/cart_hw/cart_hw.c

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/****************************************************************************
* Genesis Plus
* Cartridge Hardware support
*
* Copyright (C) 2007, 2008, 2009 Eke-Eke (GCN/Wii port)
*
* Most cartridge protections documented by Haze
* (http://haze.mameworld.info/)
*
* Realtec mapper documented by TascoDeluxe
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
***************************************************************************/
#include "shared.h"
#define CART_CNT 26
extern int emulate_address_error;
/* Global Variables */
T_CART_HW cart_hw;
uint8 j_cart;
uint8 *default_rom;
int old_system[2] = {-1,-1};
/* Function prototypes */
void default_time_w(uint32 address, uint32 data);
void special_mapper_w(uint32 address, uint32 data);
void realtec_mapper_w(uint32 address, uint32 data);
void seganet_mapper_w(uint32 address, uint32 data);
uint32 radica_mapper_r(uint32 address);
void default_regs_w(uint32 address, uint32 data);
uint32 default_regs_r(uint32 address);
void special_regs_w(uint32 address, uint32 data);
/* Cart database entry */
typedef struct
{
uint16 chk_1; /* header checksum */
uint16 chk_2; /* real checksum */
uint8 bank_start; /* first mapped bank in $400000-$7fffff region */
uint8 bank_end; /* last mapped bank in $400000-$7fffff region */
T_CART_HW cart_hw; /* hardware description */
} T_CART_ENTRY;
/* Games that need extra hardware emulation:
- copy protection device
- custom ROM banking device
*/
static const T_CART_ENTRY rom_database[CART_CNT] =
{
/* Game no Kanzume Otokuyou */
{0x0000,0xf9d1,0,0,{{0,0,0,0},{0,0,0,0},{0,0,0,0},0,0,0,seganet_mapper_w,0,0}},
/* RADICA (Volume 1) (not byteswapped) */
{0x0000,0x2326,0,0,{{0,0,0,0},{0,0,0,0},{0,0,0,0},0,1,radica_mapper_r,0,0,0}},
/* RADICA (Volume 2) */
{0x4f10,0x0836,0,0,{{0,0,0,0},{0,0,0,0},{0,0,0,0},0,1,radica_mapper_r,0,0,0}},
/* RADICA (Volume 1) */
{0xf424,0x9f82,0,0,{{0,0,0,0},{0,0,0,0},{0,0,0,0},0,1,radica_mapper_r,0,0,0}},
/* Funny World & Balloon Boy */
{0x0000,0x06ab,0x40,0x40,{{0,0,0,0},{0,0,0,0},{0,0,0,0},1,1,0,0,0,realtec_mapper_w}},
/* Whac-a-Critter */
{0xffff,0xf863,0x40,0x40,{{0,0,0,0},{0,0,0,0},{0,0,0,0},1,1,0,0,0,realtec_mapper_w}},
/* Earth Defense */
{0xffff,0x44fb,0x40,0x40,{{0,0,0,0},{0,0,0,0},{0,0,0,0},1,1,0,0,0,realtec_mapper_w}},
/* Super Mario 2 1998 */
{0xffff,0x0474,0,0,{{0x0a,0,0,0},{0xffffff,0,0,0},{0xa13000,0,0,0},0,0,default_regs_r,0,0,0}},
/* Super Mario 2 1998 */
{0x2020,0xb4eb,0,0,{{0x1c,0,0,0},{0xffffff,0,0,0},{0xa13000,0,0,0},0,0,default_regs_r,0,0,0}},
/* Supper Bubble Bobble */
{0x0000,0x16cd,0x40,0x40,{{0x55,0x0f,0,0},{0xffffff,0xffffff,0,0},{0x400000,0x400002,0,0},0,0,0,0,default_regs_r,0}},
/* Mahjong Lover */
{0x0000,0x7037,0x40,0x40,{{0x90,0xd3,0,0},{0xffffff,0xffffff,0,0},{0x400000,0x401000,0,0},0,0,0,0,default_regs_r,0}},
/* Lion King 2 */
{0xffff,0x1d9b,0x40,0x40,{{0,0,0,0},{0xfffffd,0xfffffd,0,0},{0x400000,0x400004,0,0},0,0,0,0,default_regs_r,default_regs_w}},
/* Squirell King */
{0x0000,0x8ec8,0x40,0x40,{{0,0,0,0},{0xfffffd,0xfffffd,0,0},{0x400000,0x400004,0,0},0,0,0,0,default_regs_r,default_regs_w}},
/* Rockman X3 */
{0x0000,0x9d0e,0x40,0x40,{{0x0c,0x88,0,0},{0xffffff,0xffffff,0,0},{0xa13000,0x400004,0,0},0,0,default_regs_r,0,default_regs_r,0}},
/* A Bug's Life */
{0x7f7f,0x2aad,0,0,{{0x28,0x1f,0x01,0},{0xffffff,0xffffff,0xffffff,0},{0xa13000,0xa13002,0xa1303e,0},0,0,default_regs_r,0,0,0}},
/* King of Fighter 99 */
{0x0000,0x21e,0,0,{{0x00,0x01,0x1f,0},{0xffffff,0xffffff,0xffffff,0},{0xa13000,0xa13002,0xa1303e,0},0,0,default_regs_r,0,0,0}},
/* Pocket Monster */
{0xd6fc,0x1eb1,0,0,{{0x00,0x01,0x1f,0},{0xffffff,0xffffff,0xffffff,0},{0xa13000,0xa13002,0xa1303e,0},0,0,default_regs_r,0,0,0}},
/* Lion King 3 */
{0x0000,0x507c,0x60,0x7f,{{0,0,0,0},{0xf0000e,0xf0000e,0xf0000e,0},{0x600000,0x600002,0x600004,0},0,1,0,0,default_regs_r,special_regs_w}},
/* Super King Kong 99 */
{0x0000,0x7d6e,0x60,0x7f,{{0,0,0,0},{0xf0000e,0xf0000e,0xf0000e,0},{0x600000,0x600002,0x600004,0},0,1,0,0,default_regs_r,special_regs_w}},
/* Pokemon Stadium */
{0x0000,0x843c,0x70,0x7f,{{0,0,0,0},{0,0,0,0},{0,0,0,0},0,1,0,0,0,special_regs_w}},
/* Elf Wor */
{0x0080,0x3dba,0x40,0x40,{{0x55,0x0f,0xc9,0x18},{0xffffff,0xffffff,0xffffff,0xffffff},{0x400000,0x400002,0x400004,0x400006},0,0,0,0,default_regs_r,0}},
/* Huan Le Tao Qi Shu - Smart Mouse */
{0x0000,0x1a28,0x40,0x40,{{0x55,0x0f,0xaa,0xf0},{0xffffff,0xffffff,0xffffff,0xffffff},{0x400000,0x400002,0x400004,0x400006},0,0,0,0,default_regs_r,0}},
/* Ya-Se Chuanshuo */
{0xffff,0xd472,0x40,0x40,{{0x63,0x98,0xc9,0x18},{0xffffff,0xffffff,0xffffff,0xffffff},{0x400000,0x400002,0x400004,0x400006},0,0,0,0,default_regs_r,0}},
/* Soul Blade */
{0x0000,0x0c5b,0x40,0x40,{{0x00,0x98,0xc9,0xF0},{0xffffff,0xffffff,0xffffff,0xffffff},{0x400000,0x400002,0x400004,0x400006},0,0,0,0,default_regs_r,0}},
/* King of Fighter 98 */
{0x0000,0xd0a0,0x48,0x4f,{{0xaa,0xa0,0xf0,0xa0},{0xfc0000,0xffffff,0xffffff,0xffffff},{0x480000,0x4c82c0,0x4cdda0,0x4f8820},0,0,0,0,default_regs_r,0}},
/* Lian Huan Pao - Barver Battle Saga */
{0x30b9,0x1c2a,0x40,0x40,{{0,0,0,0},{0,0,0,0},{0,0,0,0},0,0,0,0,default_regs_r,0}}
};
/* temporary memory chunk */
static uint8 mem_chunk[0x10000];
/************************************************************
Cart Hardware initialization
*************************************************************/
/* hardware that need to be reseted on power on */
void cart_hw_reset()
{
int i;
/* reset bankshifting */
if (cart_hw.bankshift)
{
for (i=0x00; i<0x40; i++)
m68k_memory_map[i].base = cart_rom + (i<<16);
}
/* Realtec mapper */
if (cart_hw.realtec & 1)
{
/* enable BOOTROM */
for (i=0; i<0x40; i++) m68k_memory_map[i].base = mem_chunk;
for (i=0; i<8; i++) memcpy(mem_chunk + i*0x2000, cart_rom + 0x7e000, 0x2000);
cart_hw.realtec |= 2;
}
/* SVP chip */
if (svp) svp_reset();
/* Lock-ON */
switch (config.lock_on)
{
case GAME_GENIE:
ggenie_reset();
break;
case ACTION_REPLAY:
datel_reset();
break;
case SONIC_KNUCKLES:
break;
default:
break;
}
/* save default cartridge slot mapping */
default_rom = m68k_memory_map[0].base;
}
/* cart hardware detection */
void cart_hw_init()
{
int i;
/**********************************************
DEFAULT CARTRIDGE MAPPING
***********************************************/
for (i=0; i<0x40; i++)
{
/* cartridge ROM */
m68k_memory_map[i].base = cart_rom + (i<<16);
m68k_memory_map[i].read8 = NULL;
m68k_memory_map[i].read16 = NULL;
m68k_memory_map[i].write8 = m68k_unused_8_w;
m68k_memory_map[i].write16 = m68k_unused_16_w;
zbank_memory_map[i].read = NULL;
zbank_memory_map[i].write = zbank_unused_w;
}
for (i=0x40; i<0x80; i++)
{
/* unused area */
m68k_memory_map[i].base = cart_rom + (i<<16);
m68k_memory_map[i].read8 = m68k_read_bus_8;
m68k_memory_map[i].read16 = m68k_read_bus_16;
m68k_memory_map[i].write8 = m68k_unused_8_w;
m68k_memory_map[i].write16 = m68k_unused_16_w;
zbank_memory_map[i].read = zbank_unused_r;
zbank_memory_map[i].write = zbank_unused_w;
}
/* restore previous setting */
if (old_system[0] != -1) input.system[0] = old_system[0];
if (old_system[1] != -1) input.system[1] = old_system[1];
/**********************************************
EXTERNAL RAM
***********************************************/
sram_init();
eeprom_init();
if (sram.on)
{
if (sram.custom)
{
/* serial EEPROM */
m68k_memory_map[eeprom.type.sda_out_adr >> 16].read8 = eeprom_read_byte;
m68k_memory_map[eeprom.type.sda_out_adr >> 16].read16 = eeprom_read_word;
m68k_memory_map[eeprom.type.sda_in_adr >> 16].read8 = eeprom_read_byte;
m68k_memory_map[eeprom.type.sda_in_adr >> 16].read16 = eeprom_read_word;
m68k_memory_map[eeprom.type.scl_adr >> 16].write8 = eeprom_write_byte;
m68k_memory_map[eeprom.type.scl_adr >> 16].write16 = eeprom_write_word;
zbank_memory_map[eeprom.type.sda_out_adr >> 16].read = eeprom_read_byte;
zbank_memory_map[eeprom.type.sda_in_adr >> 16].read = eeprom_read_byte;
zbank_memory_map[eeprom.type.scl_adr >> 16].write = eeprom_write_byte;
}
else
{
/* Static RAM (64k max.) */
m68k_memory_map[sram.start >> 16].base = sram.sram;
m68k_memory_map[sram.start >> 16].read8 = NULL;
m68k_memory_map[sram.start >> 16].read16 = NULL;
m68k_memory_map[sram.start >> 16].write8 = NULL;
m68k_memory_map[sram.start >> 16].write16 = NULL;
zbank_memory_map[sram.start >> 16].read = NULL;
zbank_memory_map[sram.start >> 16].write = NULL;
}
}
/**********************************************
CARTRIDGE LOCK-ON
***********************************************/
switch (config.lock_on)
{
case GAME_GENIE:
ggenie_init();
break;
case ACTION_REPLAY:
datel_init();
break;
case SONIC_KNUCKLES:
break;
default:
break;
}
/**********************************************
SVP CHIP
***********************************************/
svp = NULL;
if (strstr(rominfo.international,"Virtua Racing") != NULL)
{
svp_init();
m68k_memory_map[0x30].base = svp->dram;
m68k_memory_map[0x30].read16 = NULL;
m68k_memory_map[0x30].write16 = svp_write_dram;
m68k_memory_map[0x31].base = svp->dram + 0x10000;
m68k_memory_map[0x31].read16 = NULL;
m68k_memory_map[0x31].write16 = svp_write_dram;
m68k_memory_map[0x39].read16 = svp_read_cell_1;
m68k_memory_map[0x3a].read16 = svp_read_cell_2;
}
/* default GUN settings */
input.x_offset = 0x00;
input.y_offset = 0x00;
/**********************************************
SEGA MENACER
***********************************************/
if (strstr(rominfo.international,"MENACER") != NULL)
{
/* save current setting */
if (old_system[0] == -1) old_system[0] = input.system[0];
if (old_system[1] == -1) old_system[1] = input.system[1];
input.system[0] = NO_SYSTEM;
input.system[1] = SYSTEM_MENACER;
input.x_offset = 0x52;
input.y_offset = 0x00;
}
else if (strstr(rominfo.international,"T2 ; THE ARCADE GAME") != NULL)
{
/* save current setting */
if (old_system[0] == -1) old_system[0] = input.system[0];
if (old_system[1] == -1) old_system[1] = input.system[1];
input.system[0] = SYSTEM_GAMEPAD;
input.system[1] = SYSTEM_MENACER;
input.x_offset = 0x84;
input.y_offset = 0x08;
}
else if (strstr(rominfo.international,"BODY COUNT") != NULL)
{
/* save current setting */
if (old_system[0] == -1) old_system[0] = input.system[0];
if (old_system[1] == -1) old_system[1] = input.system[1];
input.system[0] = SYSTEM_MOUSE;
input.system[1] = SYSTEM_MENACER;
input.x_offset = 0x44;
input.y_offset = 0x18;
}
/**********************************************
KONAMI JUSTIFIER
***********************************************/
else if (strstr(rominfo.international,"LETHAL ENFORCERSII") != NULL)
{
/* save current setting */
if (old_system[0] == -1) old_system[0] = input.system[0];
if (old_system[1] == -1) old_system[1] = input.system[1];
input.system[0] = SYSTEM_GAMEPAD;
input.system[1] = SYSTEM_JUSTIFIER;
input.x_offset = 0x18;
input.y_offset = 0x00;
}
else if (strstr(rominfo.international,"LETHAL ENFORCERS") != NULL)
{
/* save current setting */
if (old_system[0] == -1) old_system[0] = input.system[0];
if (old_system[1] == -1) old_system[1] = input.system[1];
input.system[0] = SYSTEM_GAMEPAD;
input.system[1] = SYSTEM_JUSTIFIER;
input.x_offset = 0x00;
input.y_offset = 0x00;
}
/**********************************************
J-CART
***********************************************/
j_cart = 0;
if (((strstr(rominfo.product,"00000000") != NULL) && (rominfo.checksum == 0x168b)) || /* Super Skidmarks, Micro Machines Military*/
((strstr(rominfo.product,"00000000") != NULL) && (rominfo.checksum == 0x165e)) || /* Pete Sampras Tennis (1991), Micro Machines 96 */
((strstr(rominfo.product,"00000000") != NULL) && (rominfo.checksum == 0xcee0)) || /* Micro Machines Military (bad) */
((strstr(rominfo.product,"00000000") != NULL) && (rominfo.checksum == 0x2c41)) || /* Micro Machines 96 (bad) */
((strstr(rominfo.product,"XXXXXXXX") != NULL) && (rominfo.checksum == 0xdf39)) || /* Sampras Tennis 96 */
((strstr(rominfo.product,"T-123456") != NULL) && (rominfo.checksum == 0x1eae)) || /* Sampras Tennis 96 */
((strstr(rominfo.product,"T-120066") != NULL) && (rominfo.checksum == 0x16a4)) || /* Pete Sampras Tennis (1994)*/
(strstr(rominfo.product,"T-120096") != NULL)) /* Micro Machines 2 */
{
if (genromsize <= 0x380000) /* just to be sure (checksum might not be enough) */
{
j_cart = 1;
m68k_memory_map[0x38].read16 = jcart_read;
m68k_memory_map[0x38].write16 = jcart_write;
m68k_memory_map[0x3f].read16 = jcart_read;
m68k_memory_map[0x3f].write16 = jcart_write;
/* save current setting */
if (old_system[0] == -1) old_system[0] = input.system[0];
if (old_system[1] == -1) old_system[1] = input.system[1];
/* PORT B by default */
input.system[0] = SYSTEM_GAMEPAD;
input.system[1] = SYSTEM_GAMEPAD;
}
}
/**********************************************
Mappers & HW registers
***********************************************/
memset(&cart_hw, 0, sizeof(cart_hw));
/* search for game into database */
for (i=0; i < CART_CNT + 1; i++)
{
/* known cart found ! */
if ((rominfo.checksum == rom_database[i].chk_1) &&
(realchecksum == rom_database[i].chk_2))
{
/* retrieve hardware information */
memcpy(&cart_hw, &(rom_database[i].cart_hw), sizeof(cart_hw));
/* initialize memory handlers for $400000-$7fffff region */
int j = rom_database[i].bank_start;
while (j <= rom_database[i].bank_end)
{
if (cart_hw.regs_r)
{
m68k_memory_map[j].read8 = cart_hw.regs_r;
m68k_memory_map[j].read16 = cart_hw.regs_r;
zbank_memory_map[j].read = cart_hw.regs_r;
}
if (cart_hw.regs_w)
{
m68k_memory_map[j].write8 = cart_hw.regs_w;
m68k_memory_map[j].write16 = cart_hw.regs_w;
zbank_memory_map[j].write = cart_hw.regs_w;
}
j++;
}
/* leave loop */
i = CART_CNT + 1;
}
}
#if M68K_EMULATE_ADDRESS_ERROR
/* default behavior */
emulate_address_error = config.addr_error;
#endif
/* detect ROM files larger than 4MB */
if (genromsize > 0x800000)
{
/* Ultimate MK3 (hack) */
for (i=0x40; i<0xA0; i++)
{
m68k_memory_map[i].base = cart_rom + (i<<16);
m68k_memory_map[i].read8 = NULL;
m68k_memory_map[i].read16 = NULL;
zbank_memory_map[i].read = NULL;
}
#if M68K_EMULATE_ADDRESS_ERROR
/* this game does not work properly on real hardware */
emulate_address_error = 0;
#endif
}
else if (genromsize > 0x400000)
{
/* assume SSF2 mapper */
cart_hw.bankshift = 1;
}
/* default write handler for !TIME signal */
/* TODO: handle Sonic & Knuckles + Sonic 2 case to prevent RAM activation */
if (!cart_hw.time_w) cart_hw.time_w = default_time_w;
}
/************************************************************
MAPPER handlers
*************************************************************/
/*
"official" ROM/RAM switch
*/
static inline void sega_mapper_w(uint32 address, uint32 data)
{
uint32 i,slot = (address >> 1) & 7;
uint8 *src;
switch (slot)
{
case 0:
/* ROM/SRAM switch (Phantasy Star IV, Story of Thor/Beyond Oasis, Sonic 3 & Knuckles) */
if (data & 1)
{
/* SRAM enabled */
m68k_memory_map[0x20].base = sram.sram;
if (data & 2)
{
/* SRAM write disabled */
m68k_memory_map[0x20].write8 = m68k_unused_8_w;
m68k_memory_map[0x20].write16 = m68k_unused_16_w;
zbank_memory_map[0x20].write = zbank_unused_w;
}
else
{
/* SRAM write enabled */
m68k_memory_map[0x20].write8 = NULL;
m68k_memory_map[0x20].write16 = NULL;
zbank_memory_map[0x20].write = NULL;
}
}
else
{
/* ROM enabled */
m68k_memory_map[0x20].base = cart_rom + 0x200000;
}
break;
default:
/* ROM Bankswitch (Super Street Fighter 2)
documented by Bart Trzynadlowski (http://www.trzy.org/files/ssf2.txt)
*/
slot = slot << 3; /* 8 x 512k banks */
src = cart_rom + (data << 19);
for (i=0; i<8; i++) m68k_memory_map[slot++].base = src + (i<<16);
break;
}
}
/*
custom ROM Bankswitch used by pirate "Multi-in-1" carts
*/
static inline void multi_mapper_w(uint32 address, uint32 data)
{
int i;
cart_hw.bankshift = 1;
/* 64 x 64k banks */
for (i=0; i<64; i++)
{
m68k_memory_map[i].base = &cart_rom[((address++) & 0x3f) << 16];
}
}
/*
Special ROM Bankswitch used for copy protection
Used by unlicensed cartridges (Lion King III, Super King Kong 99)
*/
void special_mapper_w(uint32 address, uint32 data)
{
/* 1 x 32k bank */
m68k_memory_map[0].base = mem_chunk;
memcpy(mem_chunk,&cart_rom[(data & 0x7f) << 15],0x8000);
memcpy(mem_chunk+0x8000,cart_rom + 0x8000,0x8000);
}
/*
Realtec ROM Bankswitch (Earth Defend, Balloon Boy & Funny World, Whac-A-Critter)
*/
void realtec_mapper_w(uint32 address, uint32 data)
{
int i;
uint32 base;
/* 32 x 128k banks */
switch (address)
{
case 0x404000: /* three lower bits of ROM base address */
cart_hw.regs[0] = data & 7;
base = ((data & 7) | (cart_hw.regs[1] << 2));
for (i=0; i<=cart_hw.regs[2]; i++)
{
m68k_memory_map[i*2].base = &cart_rom[((base + i)*2 & 0x3f) << 16];
m68k_memory_map[i*2+1].base = &cart_rom[(((base + i)*2 + 1) & 0x3f) << 16];
}
return;
case 0x400000: /* two higher bits of ROM base address */
cart_hw.regs[1] = data & 6;
base = cart_hw.regs[0] | ((data & 6) << 2);
for (i=0; i<=cart_hw.regs[2]; i++)
{
m68k_memory_map[i*2].base = &cart_rom[((base + i)*2 & 0x3f) << 16];
m68k_memory_map[i*2+1].base = &cart_rom[(((base + i)*2 + 1) & 0x3f) << 16];
}
return;
case 0x402000: /* number of 128k blocks to map */
cart_hw.regs[2] = data & 0x1f;
base = cart_hw.regs[0] | (cart_hw.regs[1] << 2);
for (i=0; i<=(data & 0x1f); i++)
{
m68k_memory_map[i*2].base = &cart_rom[((base + i)*2 & 0x3f) << 16];
m68k_memory_map[i*2+1].base = &cart_rom[(((base + i)*2 + 1) & 0x3f) << 16];
}
return;
}
}
/* Game no Kanzume Otokuyou ROM Mapper */
void seganet_mapper_w(uint32 address, uint32 data)
{
if ((address & 0xff) == 0xf1)
{
int i;
if (data & 1)
{
/* ROM Write protected */
for (i=0; i<0x40; i++)
{
m68k_memory_map[i].write8 = m68k_unused_8_w;
m68k_memory_map[i].write16 = m68k_unused_16_w;
zbank_memory_map[i].write = zbank_unused_w;
}
}
else
{
/* ROM Write enabled */
for (i=0; i<0x40; i++)
{
m68k_memory_map[i].write8 = NULL;
m68k_memory_map[i].write16 = NULL;
zbank_memory_map[i].write = NULL;
}
}
}
}
/*
RADICA ROM Bankswitch (use !TIME)
*/
uint32 radica_mapper_r(uint32 address)
{
int i = 0;
address = (address >> 1);
/* 64 x 64k banks */
for (i = 0; i < 64; i++)
{
m68k_memory_map[i].base = &cart_rom[((address++)& 0x3f)<< 16];
}
return 0xff;
}
/************************************************************
default !TIME signal handler
*************************************************************/
/* default ROM bankswitch */
void default_time_w(uint32 address, uint32 data)
{
if ((address & 0xf1) == 0xf1) sega_mapper_w(address, data);
else if (address < 0xa13040) multi_mapper_w(address, data);
}
/************************************************************
Internal register handlers
*************************************************************/
uint32 default_regs_r(uint32 address)
{
int i;
for (i=0; i<4; i++)
{
if ((address & cart_hw.mask[i]) == cart_hw.addr[i])
return cart_hw.regs[i];
}
/* unused */
return 0xffff;
}
void default_regs_w(uint32 address, uint32 data)
{
int i;
for (i=0; i<4; i++)
{
if ((address & cart_hw.mask[i]) == cart_hw.addr[i])
{
cart_hw.regs[i] = data;
}
}
}
/* special register behaviour (Lion King III, Super Donkey Kong 99) */
void special_regs_w(uint32 address, uint32 data)
{
/* ROM bankswitch */
if ((address >> 16) > 0x6f)
{
special_mapper_w(address, data);
return;
}
/* write regs */
default_regs_w(address, data);
/* bitswapping (documented by Haze) */
uint32 temp = cart_hw.regs[0];
switch (cart_hw.regs[1])
{
case 1:
cart_hw.regs[2] = (temp >> 1);
return;
case 2:
cart_hw.regs[2] = ((temp >> 4) | ((temp & 0x0F) << 4));
return;
default:
cart_hw.regs[2] = (((temp >> 7) & 0x01) | ((temp >> 5) & 0x02) |
((temp >> 3) & 0x04) | ((temp >> 1) & 0x08) |
((temp << 1) & 0x10) | ((temp << 3) & 0x20) |
((temp << 5) & 0x40) | ((temp << 7) & 0x80));
return;
}
}
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