diff --git a/src/boards/606.c b/src/boards/606.c
new file mode 100644
index 0000000..212b129
--- /dev/null
+++ b/src/boards/606.c
@@ -0,0 +1,61 @@
+/* FCE Ultra - NES/Famicom Emulator
+ *
+ * Copyright notice for this file:
+ *  Copyright (C) 2026 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 "asic_latch.h"
+
+static uint8 reg;
+
+static void sync () {
+	if (reg &0x80) { /* ANROM mode */
+		setprg32(0x8000, reg >>2 &0x08 | reg >>4 &0x04 | Latch_data &0x03);
+		setmirror(Latch_data &0x10? MI_1: MI_0);
+	} else { /* UNROM mode */
+		setprg16(0x8000, reg >>1 &0x10 | reg >>3 &0x08 | Latch_data &0x07);
+		setprg16(0xC000, reg >>1 &0x10 | reg >>3 &0x08 |             0x07);
+		setmirror(Latch_data &0x10? MI_H: MI_V);
+	}
+	setchr8(0);
+}
+
+static DECLFW (writeReg) {
+	if (~reg &0x10) {
+		reg = V;
+		sync();
+	}
+}
+
+static void reset () {
+	reg = 0;
+	Latch_clear();
+}
+
+static void power () {
+	Latch_power();
+	SetWriteHandler(0x6000, 0x7FFF, writeReg);
+	reset();
+}
+
+void Mapper606_Init (CartInfo *info) {
+	Latch_init(info, sync, 0x8000, 0xFFFF, NULL);
+	info->Power = power;
+	info->Reset = reset;
+	AddExState(&reg, 1, 0, "REGS");
+}
diff --git a/src/ines.c b/src/ines.c
index 9c9d21d..765ad71 100644
--- a/src/ines.c
+++ b/src/ines.c
@@ -1023,6 +1023,7 @@ INES_BOARD_BEGIN()
 	INES_BOARD( "ET-133A",                  599, Mapper599_Init         )
 	INES_BOARD( "J-2061",                   603, Mapper603_Init         )
 	INES_BOARD( "New Star TX5/8IN1",        605, Mapper605_Init         )
+	INES_BOARD( "New Star T4IN1",           606, Mapper606_Init         )
 INES_BOARD_END()
 
 static uint32 iNES_get_mapper_id(void)
diff --git a/src/ines.h b/src/ines.h
index 8234dc8..8fc9f6d 100644
--- a/src/ines.h
+++ b/src/ines.h
@@ -492,6 +492,7 @@ void Mapper598_Init(CartInfo *);
 void Mapper599_Init(CartInfo *);
 void Mapper603_Init(CartInfo *);
 void Mapper605_Init(CartInfo *);
+void Mapper606_Init(CartInfo *);
 void FFE_Init(CartInfo *);
 
 #endif