Add mapper 504.

src/boards/504.c

@@ -0,0 +1,65 @@
+/* FCEUmm - NES/Famicom Emulator
+ *
+ * Copyright notice for this file:
+ *  Copyright (C) 2020
+ *
+ * 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"
+#include "asic_mmc3.h"
+
+static uint8 reg;
+
+static void sync() {
+	int prgAND = reg &0x02? 0x0F: 0x1F;
+	int chrAND = reg &0x02? 0x7F: 0xFF;
+	int prgOR = reg <<4;
+	int chrOR = reg <<7;
+	MMC3_syncPRG(prgAND, prgOR &~prgAND);
+	MMC3_syncCHR(chrAND, chrOR &~chrAND);
+	MMC3_syncMirror();
+}
+
+static int getPRGBank(uint8 bank) {
+	if ((reg &0x03) == 0x03 && ~reg &0x08)
+		return MMC3_getPRGBank(bank &1) &~1 | bank &1;
+	else
+		return MMC3_getPRGBank(bank);
+}
+
+static DECLFW(writeReg) {
+	reg = A &0xFF;
+	sync();
+}
+
+static void reset() {
+	reg = 0;
+	sync();
+}
+
+static void power() {
+	reg = 0;
+	MMC3_power();
+}
+
+void Mapper504_Init(CartInfo *info) {
+	MMC3_init(info, sync, MMC3_TYPE_AX5202P, getPRGBank, NULL, NULL, writeReg);
+	info->Power = power;
+	info->Reset = reset;
+	AddExState(&reg, 1, 0, "EXPR");
+}