fceugx/source/fceultra/boards/50.cpp
2012-12-14 17:18:20 +00:00

85 lines
2.0 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
*
* FDS Conversion
*
*/
#include "mapinc.h"
static uint8 reg;
static uint32 IRQCount, IRQa;
static SFORMAT StateRegs[] =
{
{ &IRQCount, 4, "IRQC" },
{ &IRQa, 4, "IRQA" },
{ &reg, 1, "REG" },
{ 0 }
};
static void Sync(void) {
setprg8(0x6000, 0xF);
setprg8(0x8000, 0x8);
setprg8(0xa000, 0x9);
setprg8(0xc000, reg);
setprg8(0xe000, 0xB);
setchr8(0);
}
static DECLFW(M50Write) {
switch (A & 0xD160) {
case 0x4120: IRQa = V & 1; if (!IRQa) IRQCount = 0; X6502_IRQEnd(FCEU_IQEXT); break;
case 0x4020: reg = ((V & 1) << 2) | ((V & 2) >> 1) | ((V & 4) >> 1) | (V & 8); Sync(); break;
}
}
static void M50Power(void) {
reg = 0;
Sync();
SetReadHandler(0x6000, 0xffff, CartBR);
SetWriteHandler(0x4020, 0x5fff, M50Write);
}
static void M50Reset(void) {
}
static void M50IRQHook(int a) {
if (IRQa) {
if (IRQCount < 4096)
IRQCount += a;
else{
IRQa = 0;
X6502_IRQBegin(FCEU_IQEXT);
}
}
}
static void StateRestore(int version) {
Sync();
}
void Mapper50_Init(CartInfo *info) {
info->Reset = M50Reset;
info->Power = M50Power;
MapIRQHook = M50IRQHook;
GameStateRestore = StateRestore;
AddExState(&StateRegs, ~0, 0, 0);
}