Adding software-selectable mirroring to mapper 166/167. Rewrite mapper 518.

2025-09-13 12:31:58 +02:00
parent 29a0caf61b
commit 5d88968cf9
6 changed files with 99 additions and 115 deletions
--- a/src/boards/518.c
+++ b/src/boards/518.c
@@ -0,0 +1,95 @@
+/* FCE Ultra - NES/Famicom Emulator
+ *
+ * Copyright notice for this file:
+ *  Copyright (C) 2025 NewRisingSun
+ *
+ * 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 "cartram.h"
+
+static uint8 reg[2];
+static uint8 chr;
+
+static void sync () {
+	setprg8r(0x10, 0x6000, 0);
+	if (reg[1] &0x04)
+		setprg32(0x8000, reg[0]);
+	else {
+		setprg16(0x8000, reg[0]);
+		setprg16(0xC000, 0);
+	}
+	setchr4(0x0000, reg[1] &0x02? chr: 0);
+	setchr4(0x1000, 1);
+	setmirror(reg[1] &0x01? MI_H: MI_V);
+}
+
+static void FP_FASTAPASS(1) trapPPUAddressChange (uint32 A) {
+	if (A &0x2000 && (A &0x23C0) < 0x23C0) {
+		chr = A >>(10 +(reg[1] &0x01? 1: 0)) &1;
+		setchr4(0x0000, reg[1] &0x02? chr: 0);
+	}
+}
+
+static DECLFR (readReg) {
+	switch(A >>8 &7) {
+		case 3: /* LPC state */
+			return 0x8F;
+		case 6: /* FDC */
+			return 0x00;
+		default:
+			return X.DB;
+	}
+}
+
+static DECLFW (writeReg) {
+	switch(A >>8 &7) {
+		case 0: case 2:
+			reg[A >>9 &1] = V;
+			sync();
+			break;
+		case 3: /* LPC data */
+			break;
+		case 5: /* FDC */
+			break;
+	}
+}
+
+static void reset () {
+	reg[0] = reg[1] = chr = 0;
+	sync();
+}
+
+static void power () {
+	SetReadHandler(0x5000, 0x5FFF, readReg);
+	SetReadHandler(0x6000, 0xFFFF, CartBR);
+	SetWriteHandler(0x5000, 0x5FFF, writeReg);
+	SetWriteHandler(0x6000, 0xFFFF, CartBW);
+	reset();
+}
+
+static void restore (int version) {
+	sync();
+}
+
+void Mapper518_Init (CartInfo *info) {
+	WRAM_init(info, 8);
+	info->Power = power;
+	info->Reset = reset;
+	GameStateRestore = restore;
+	PPU_hook = trapPPUAddressChange;
+	AddExState(&chr, 1, 0, "CHRB");
+}