From f56be8ce5e5c379c0ae12d64107744aee769592a Mon Sep 17 00:00:00 2001
From: NewRisingSun <8vytz1+dhp372pv94ebg@sharklasers.com>
Date: Fri, 12 Sep 2025 01:25:50 +0200
Subject: [PATCH] Add mapper 548.

---
 src/boards/548.c | 107 +++++++++++++++++++++++++++++++++++++++++++++++
 src/ines.c       |   1 +
 src/ines.h       |   1 +
 3 files changed, 109 insertions(+)
 create mode 100644 src/boards/548.c

diff --git a/src/boards/548.c b/src/boards/548.c
new file mode 100644
index 0000000..0ca04ca
--- /dev/null
+++ b/src/boards/548.c
@@ -0,0 +1,107 @@
+/* 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
+ *
+ *
+ */
+
+/* The UNIF dump of "(JY-103) 3-in-1" (JY4M4 MAPR) has a strange bank order and will not run with this emulation. */
+
+#include "mapinc.h"
+#include "wram.h"
+#include "../fds_apu.h"
+
+static uint8 reg;
+static uint8 latch;
+static uint8 counting;
+static uint16 counter;
+
+static SFORMAT stateRegs[] ={
+	{ &reg, 1, "REGM" },
+	{ &latch, 1, "LATC" },
+	{ &counting, 1, "IRQA" },
+	{ &counter, 2, "IRQC" },
+        { 0 }
+};
+
+static void sync () {
+	setprg8r(0x10, 0x6000, 0);
+	setprg16(0x8000, reg);
+	setprg16(0xC000, 3);
+	setchr8(0);
+}
+
+static DECLFW (writeLatch) {
+	latch = A >>2 &0x03 | A >>3 &0x04;
+	if (A &4) {
+		counting = 0;
+		counter = 0;
+		X6502_IRQEnd(FCEU_IQEXT);
+	} else
+		counting = 1;
+}
+
+static DECLFW (writeReg) {
+	reg = latch ^0x05;
+	sync();
+}
+
+static void FP_FASTAPASS(1) cpuCycle (int a) {
+	while (a--) {
+		if (counting) {
+			if (counter == 23680)
+				X6502_IRQBegin(FCEU_IQEXT);
+			else
+			if (counter == 24320)
+				X6502_IRQEnd(FCEU_IQEXT);
+			counter++;
+		}
+	}
+}
+
+static void reset() {
+	FDSSoundReset();
+	X6502_IRQEnd(FCEU_IQEXT);
+	latch = 0x07;
+	reg = latch ^0x05;
+	counting = 0;
+	counter = 0;
+	sync();
+}
+
+static void power() {
+	FDSSoundPower();
+	SetReadHandler(0x6000, 0xFFFF, CartBR);
+	SetWriteHandler(0x4800, 0x4FFF, writeLatch);
+	SetWriteHandler(0x5000, 0x57FF, writeReg);
+	SetWriteHandler(0x6000, 0x7FFF, CartBW);
+	reset();
+}
+
+static void stateRestore(int version) {
+	sync();
+}
+
+void Mapper548_Init (CartInfo *info) {
+	WRAM_init(info, 8);
+	info->Power = power;
+	info->Reset = reset;
+	MapIRQHook = cpuCycle;
+	GameStateRestore = stateRestore;
+	AddExState(stateRegs, ~0, 0, 0);
+}
diff --git a/src/ines.c b/src/ines.c
index 51df3dd..ae50efc 100644
--- a/src/ines.c
+++ b/src/ines.c
@@ -971,6 +971,7 @@ INES_BOARD_BEGIN()
 	INES_BOARD( "WAIXING FS306",            544, Mapper544_Init         )
 	INES_BOARD( "ST-80",                    545, Mapper545_Init         )
 	INES_BOARD( "03-101",                   546, Mapper546_Init         )
+	INES_BOARD( "CTC-15",                   548, Mapper548_Init         )
 	INES_BOARD( "Kaiser KS-7016B",          549, Mapper549_Init         )
 	INES_BOARD( "",                         550, Mapper550_Init         )
 	INES_BOARD( "",              		551, Mapper178_Init         )
diff --git a/src/ines.h b/src/ines.h
index a7b1b53..a56fd6b 100644
--- a/src/ines.h
+++ b/src/ines.h
@@ -439,6 +439,7 @@ void Mapper543_Init(CartInfo *);
 void Mapper544_Init(CartInfo *);
 void Mapper545_Init(CartInfo *);
 void Mapper546_Init(CartInfo *);
+void Mapper548_Init(CartInfo *);
 void Mapper549_Init(CartInfo *);
 void Mapper550_Init(CartInfo *);
 void Mapper552_Init(CartInfo *);