diff --git a/src/boards/390.c b/src/boards/390.c
new file mode 100644
index 0000000..9b88a84
--- /dev/null
+++ b/src/boards/390.c
@@ -0,0 +1,92 @@
+/* FCEUmm - NES/Famicom Emulator
+ *
+ * Copyright notice for this file:
+ * Copyright (C) 2020 negativeExponent
+ *
+ * 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.
+ */
+
+/* NES 2.0 Mapper 390 - Realtec 8031 */
+
+#include "mapinc.h"
+
+static uint8 regs[2];
+static uint8 dipswitch;
+
+static SFORMAT StateRegs[] =
+{
+	{ &regs, 2, "REG" },
+    { &dipswitch, 1, "DPSW" },
+	{ 0 }
+};
+
+static void Sync(void) {
+    switch ((regs[1] >> 4) & 3) {
+    case 0:
+    case 1:
+        /* UNROM */
+        setprg16(0x8000, regs[1]);
+        setprg16(0xC000, regs[1] | 7);
+        break;
+    case 2:
+        /* Maybe unused, NROM-256? */
+        setprg32(0x8000, regs[1] >> 1); 
+        break;
+    case 3:
+        /* NROM-128 */
+        setprg16(0x8000, regs[1]);
+        setprg16(0xC000, regs[1]);
+        break;
+    }
+    setchr8(regs[0]);
+    setmirror(((regs[0] & 0x20) >> 5) ^ 1);
+}
+
+static DECLFR(M390Read) {
+    uint8 ret = CartBR(A);
+    if ((regs[1] & 0x30) == 0x10)
+        ret |= dipswitch;
+    return ret;
+}
+
+static DECLFW(M390Write) {
+    regs[(A >> 14) & 1] = A & 0x3F;
+    Sync();
+}
+
+static void M390Power(void) {
+    regs[0] = 0;
+    regs[1] = 0;
+    dipswitch = 11; /* hard-coded 150-in-1 menu */
+	Sync();
+	SetReadHandler(0x8000, 0xffff, M390Read);
+    SetWriteHandler(0x8000, 0xffff, M390Write);
+}
+
+static void M390Reset(void) {
+    dipswitch = 11; /* hard-coded 150-in-1 menu */
+    Sync();
+}
+
+static void StateRestore(int version) {
+	Sync();
+}
+
+void Mapper390_Init(CartInfo *info) {
+	info->Reset = M390Reset;
+	info->Power = M390Power;
+	GameStateRestore = StateRestore;
+	AddExState(&StateRegs, ~0, 0, 0);
+}
diff --git a/src/ines.c b/src/ines.c
index 9cfa5a3..10b5fff 100644
--- a/src/ines.c
+++ b/src/ines.c
@@ -665,6 +665,7 @@ static BMAPPINGLocal bmap[] = {
 	{(uint8_t*)"MMC3 PIRATE SFC-12",	372, Mapper372_Init },
 	{(uint8_t*)"95/96 Super HiK 4-in-1",	374, Mapper374_Init },
 	{(uint8_t*)"KN-42",					381, Mapper381_Init },
+	{(uint8_t*)"Realtec 8031",			390, Mapper390_Init },
 	{(uint8_t*)"60-1064-16L (FDS)",		538, Mapper538_Init },
 	{(uint8_t*)"LittleCom 160-in-1",	541, Mapper541_Init },
 
diff --git a/src/ines.h b/src/ines.h
index f9b8814..cb50850 100644
--- a/src/ines.h
+++ b/src/ines.h
@@ -248,6 +248,7 @@ void Mapper357_Init(CartInfo *);
 void Mapper372_Init(CartInfo *);
 void Mapper374_Init(CartInfo *);
 void Mapper381_Init(CartInfo *);
+void Mapper390_Init(CartInfo *);
 void Mapper538_Init(CartInfo *);
 void Mapper541_Init(CartInfo *);