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

140 lines
3.1 KiB
C++

/* FCE Ultra - NES/Famicom Emulator
*
* Copyright notice for this file:
* Copyright (C) 2002 Xodnizel
*
* 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
*/
#include "mapinc.h"
static uint8 cmd, mirr, regs[11];
static uint8 rmode, IRQmode, IRQCount, IRQa, IRQLatch;
static SFORMAT StateRegs[] = {
{ regs, 11, "REGS" },
{ &cmd, 1, "CMDR" },
{ &mirr, 1, "MIRR" },
{ &rmode, 1, "RMOD" },
{ &IRQmode, 1, "IRQM" },
{ &IRQCount, 1, "IRQC" },
{ &IRQa, 1, "IRQA" },
{ &IRQLatch, 1, "IRQL" },
{ 0 }
};
static void M64IRQHook(int a) {
static int32 smallcount;
if (IRQmode) {
smallcount += a;
while (smallcount >= 4) {
smallcount -= 4;
IRQCount--;
if (IRQCount == 0xFF)
if (IRQa) X6502_IRQBegin(FCEU_IQEXT);
}
}
}
static void M64HBHook(void) {
if ((!IRQmode) && (scanline != 240)) {
rmode = 0;
IRQCount--;
if (IRQCount == 0xFF) {
if (IRQa) {
rmode = 1;
X6502_IRQBegin(FCEU_IQEXT);
}
}
}
}
static void Sync(void) {
if (cmd & 0x20) {
setchr1(0x0000, regs[0]);
setchr1(0x0400, regs[8]);
setchr1(0x0800, regs[1]);
setchr1(0x0C00, regs[9]);
} else {
setchr2(0x0000, regs[0] >> 1);
setchr2(0x0800, regs[1] >> 1);
}
setchr1(0x1000, regs[2]);
setchr1(0x1400, regs[3]);
setchr1(0x1800, regs[4]);
setchr1(0x1C00, regs[5]);
setprg8(0x8000, regs[6]);
setprg8(0xA000, regs[7]);
setprg8(0xC000, regs[10]);
setprg8(0xE000, ~0);
setmirror(mirr);
}
static DECLFW(M64Write) {
switch (A & 0xF001) {
case 0xA000: mirr = (V & 1) ^ 1; Sync(); break;\
case 0x8000: cmd = V; break;
case 0x8001:
if ((cmd & 0xF) < 10)
regs[cmd & 0xF] = V;
else if ((cmd & 0xF) == 0xF)
regs[10] = V;
Sync();
break;
case 0xC000:
IRQLatch = V;
if (rmode == 1)
IRQCount = IRQLatch;
break;
case 0xC001:
rmode = 1;
IRQCount = IRQLatch;
IRQmode = V & 1;
break;
case 0xE000:
IRQa = 0;
X6502_IRQEnd(FCEU_IQEXT);
if (rmode == 1)
IRQCount = IRQLatch;
break;
case 0xE001:
IRQa = 1;
if (rmode == 1)
IRQCount = IRQLatch;
break;
}
}
static void M64Power(void) {
cmd = mirr = 0;
regs[0] = regs[1] = regs[2] = regs[3] = regs[4] = regs[5] = ~0;
regs[6] = regs[7] = regs[8] = regs[9] = regs[10] = ~0;
Sync();
SetReadHandler(0x8000, 0xFFFF, CartBR);
SetWriteHandler(0x8000, 0xFFFF, M64Write);
}
static void StateRestore(int version) {
Sync();
}
void Mapper64_Init(CartInfo *info) {
info->Power = M64Power;
GameHBIRQHook = M64HBHook;
MapIRQHook = M64IRQHook;
GameStateRestore = StateRestore;
AddExState(&StateRegs, ~0, 0, 0);
}