fceugx/source/fceultra/boards/tf-1201.cpp
2012-12-14 17:43:51 +00:00

110 lines
2.9 KiB
C++

/* FCE Ultra - NES/Famicom Emulator
*
* Copyright notice for this file:
* Copyright (C) 2005 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
*
* Lethal Weapon (VRC4 mapper)
*/
#include "mapinc.h"
static uint8 prg0, prg1, mirr, swap;
static uint8 chr[8];
static uint8 IRQCount;
static uint8 IRQPre;
static uint8 IRQa;
static SFORMAT StateRegs[] =
{
{ &prg0, 1, "PRG0" },
{ &prg0, 1, "PRG1" },
{ &mirr, 1, "MIRR" },
{ &swap, 1, "SWAP" },
{ chr, 8, "CHR" },
{ &IRQCount, 1, "IRQC" },
{ &IRQPre, 1, "IRQP" },
{ &IRQa, 1, "IRQA" },
{ 0 }
};
static void SyncPrg(void) {
if (swap & 3) {
setprg8(0x8000, ~1);
setprg8(0xC000, prg0);
} else {
setprg8(0x8000, prg0);
setprg8(0xC000, ~1);
}
setprg8(0xA000, prg1);
setprg8(0xE000, ~0);
}
static void SyncChr(void) {
int i;
for (i = 0; i < 8; i++)
setchr1(i << 10, chr[i]);
setmirror(mirr ^ 1);
}
static void StateRestore(int version) {
SyncPrg();
SyncChr();
}
static DECLFW(UNLTF1201Write) {
A = (A & 0xF003) | ((A & 0xC) >> 2);
if ((A >= 0xB000) && (A <= 0xE003)) {
int ind = (((A >> 11) - 6) | (A & 1)) & 7;
int sar = ((A & 2) << 1);
chr[ind] = (chr[ind] & (0xF0 >> sar)) | ((V & 0x0F) << sar);
SyncChr();
} else switch (A & 0xF003) {
case 0x8000: prg0 = V; SyncPrg(); break;
case 0xA000: prg1 = V; SyncPrg(); break;
case 0x9000: mirr = V & 1; SyncChr(); break;
case 0x9001: swap = V & 3; SyncPrg(); break;
case 0xF000: IRQCount = ((IRQCount & 0xF0) | (V & 0xF)); break;
case 0xF002: IRQCount = ((IRQCount & 0x0F) | ((V & 0xF) << 4)); break;
case 0xF001:
case 0xF003: IRQa = V & 2; X6502_IRQEnd(FCEU_IQEXT); if (scanline < 240) IRQCount -= 8; break;
}
}
static void UNLTF1201IRQCounter(void) {
if (IRQa) {
IRQCount++;
if (IRQCount == 237) {
X6502_IRQBegin(FCEU_IQEXT);
}
}
}
static void UNLTF1201Power(void) {
IRQPre = IRQCount = IRQa = 0;
SetReadHandler(0x8000, 0xFFFF, CartBR);
SetWriteHandler(0x8000, 0xFFFF, UNLTF1201Write);
SyncPrg();
SyncChr();
}
void UNLTF1201_Init(CartInfo *info) {
info->Power = UNLTF1201Power;
GameHBIRQHook = UNLTF1201IRQCounter;
GameStateRestore = StateRestore;
AddExState(&StateRegs, ~0, 0, 0);
}