fceugx/source/fceultra/boards/vrc1.cpp
2012-12-14 17:18:20 +00:00

71 lines
1.9 KiB
C++

/* FCE Ultra - NES/Famicom Emulator
*
* Copyright notice for this file:
* Copyright (C) 2012 CaH4e3
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* VRC-1
*
*/
#include "mapinc.h"
static uint8 preg[3], creg[2], mode;
static SFORMAT StateRegs[] =
{
{ &mode, 1, "MODE" },
{ creg, 2, "CREG" },
{ preg, 3, "PREG" },
{ 0 }
};
static void Sync(void) {
setprg8(0x8000, preg[0]);
setprg8(0xA000, preg[1]);
setprg8(0xC000, preg[2]);
setprg8(0xE000, ~0);
setchr4(0x0000, creg[0] | ((mode & 2) << 3));
setchr4(0x1000, creg[1] | ((mode & 4) << 2));
setmirror((mode & 1) ^ 1);
}
static DECLFW(M75Write) {
switch (A & 0xF000) {
case 0x8000: preg[0] = V; Sync(); break;
case 0x9000: mode = V; Sync(); break;
case 0xA000: preg[1] = V; Sync(); break;
case 0xC000: preg[2] = V; Sync(); break;
case 0xE000: creg[0] = V & 0xF; Sync(); break;
case 0xF000: creg[1] = V & 0xF; Sync(); break;
}
}
static void M75Power(void) {
Sync();
SetWriteHandler(0x8000, 0xFFFF, M75Write);
SetReadHandler(0x8000, 0xFFFF, CartBR);
}
static void StateRestore(int version) {
Sync();
}
void Mapper75_Init(CartInfo *info) {
info->Power = M75Power;
AddExState(&StateRegs, ~0, 0, 0);
GameStateRestore = StateRestore;
}