81 lines
2.2 KiB
C
81 lines
2.2 KiB
C
/* FCEUmm - NES/Famicom Emulator
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*
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* Copyright notice for this file:
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* Copyright (C) 2022 negativeExponent
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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 preg[4];
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static uint8 creg[8];
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static uint8 nt[4];
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static uint8 IRQa;
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static uint16 IRQCount;
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static SFORMAT StateRegs[] = {
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{ preg, 4, "PREG" },
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{ creg, 8, "CREG" },
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{ nt, 4, "NREG" },
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{ &IRQa, 1, "IRQA" },
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{ &IRQCount, 2, "IRQC" },
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{ 0 }
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};
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static void Sync(void) {
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int i;
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setprg8(0x8000, preg[0]);
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setprg8(0xA000, preg[1]);
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setprg8(0xC000, preg[2]);
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setprg8(0xE000, ~0);
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for (i = 0; i < 8; i++) setchr1(i << 10, creg[i]);
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setmirrorw(nt[0] & 1, nt[1] & 1, nt[2] & 1, nt[3] & 1);
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}
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static DECLFW(M417Write) {
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switch ((A >> 4) & 7) {
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case 0: preg[A & 3] = V; Sync(); break;
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case 1: creg[0 | (A & 3)] = V; Sync(); break;
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case 2: creg[4 | (A & 3)] = V; Sync(); break;break;
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case 3: IRQCount = 0; IRQa = 1; break;
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case 4: IRQa = 0; X6502_IRQEnd(FCEU_IQEXT); break;
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case 5: nt[A & 3] = V; Sync(); break;
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}
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}
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static void M417Power(void) {
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Sync();
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SetReadHandler(0x8000, 0xFFFF, CartBR);
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SetWriteHandler(0x8000, 0xFFFF, M417Write);
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}
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static void M417IRQHook(int a) {
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IRQCount += a;
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if (IRQa && IRQCount > 1024)
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X6502_IRQBegin(FCEU_IQEXT);
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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 Mapper417_Init(CartInfo *info) {
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info->Power = M417Power;
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MapIRQHook = M417IRQHook;
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GameStateRestore = StateRestore;
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AddExState(&StateRegs, ~0, 0, 0);
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}
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