mirror of
https://github.com/dborth/fceugx.git
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92 lines
2.3 KiB
C++
92 lines
2.3 KiB
C++
/* FCE Ultra - NES/Famicom Emulator
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*
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* Copyright notice for this file:
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* Copyright (C) 2002 Xodnizel
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "mapinc.h"
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static uint8 prgreg[4], chrreg[8], mirror;
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static uint8 IRQa, IRQCount, IRQLatch;
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static SFORMAT StateRegs[] =
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{
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{ &IRQa, 1, "IRQA" },
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{ &IRQCount, 1, "IRQC" },
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{ &IRQLatch, 1, "IRQL" },
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{ prgreg, 4, "PREG" },
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{ chrreg, 8, "CREG" },
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{ &mirror, 1, "MREG" },
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{ 0 }
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};
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static void Sync(void) {
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setprg8(0x8000, prgreg[0]);
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setprg8(0xa000, prgreg[1]);
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setprg8(0xc000, prgreg[2]);
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setprg8(0xe000, prgreg[3]);
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int i;
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for (i = 0; i < 8; i++)
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setchr1(i << 10, chrreg[i]);
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setmirror(mirror ^ 1);
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}
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static DECLFW(M117Write) {
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if (A < 0x8004) {
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prgreg[A & 3] = V;
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Sync();
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} else if ((A >= 0xA000) && (A <= 0xA007)) {
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chrreg[A & 7] = V;
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Sync();
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} else switch (A) {
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case 0xc001: IRQLatch = V; break;
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case 0xc003: IRQCount = IRQLatch; IRQa |= 2; break;
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case 0xe000: IRQa &= ~1; IRQa |= V & 1; X6502_IRQEnd(FCEU_IQEXT); break;
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case 0xc002: X6502_IRQEnd(FCEU_IQEXT); break;
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case 0xd000: mirror = V & 1;
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}
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}
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static void M117Power(void) {
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prgreg[0] = ~3; prgreg[1] = ~2; prgreg[2] = ~1; prgreg[3] = ~0;
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Sync();
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SetReadHandler(0x8000, 0xFFFF, CartBR);
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SetWriteHandler(0x8000, 0xFFFF, M117Write);
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}
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static void M117IRQHook(void) {
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if (IRQa == 3 && IRQCount) {
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IRQCount--;
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if (!IRQCount) {
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IRQa &= 1;
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X6502_IRQBegin(FCEU_IQEXT);
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}
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}
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}
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static void StateRestore(int version) {
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Sync();
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}
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void Mapper117_Init(CartInfo *info) {
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info->Power = M117Power;
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GameHBIRQHook = M117IRQHook;
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GameStateRestore = StateRestore;
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AddExState(&StateRegs, ~0, 0, 0);
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}
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