diff --git a/src/boards/jyasic.c b/src/boards/jyasic.c
index 0d1cdf1..cfc1b3b 100644
--- a/src/boards/jyasic.c
+++ b/src/boards/jyasic.c
@@ -21,6 +21,7 @@
  */
 
 #include "mapinc.h"
+#include "mmc3.h"
 
 void 	(*sync)(void);
 static uint8	allowExtendedMirroring;
@@ -45,6 +46,7 @@ static uint8	adder;
 static uint8	test;
 static uint8    dipSwitch;
 
+static uint8 cpuWriteHandlersSet;
 static writefunc cpuWriteHandlers[0x10000]; /* Actual write handlers for CPU write trapping as a method fo IRQ clocking */
 
 static SFORMAT JYASIC_stateRegs[] = {
@@ -373,6 +375,16 @@ static DECLFW(writeMode)
 	sync();
 }
 
+static void JYASIC_restoreWriteHandlers(void)
+{
+   int i;
+   if (cpuWriteHandlersSet) 
+   {
+	   for (i =0; i <0x10000; i++) SetWriteHandler(i, i, cpuWriteHandlers[i]);
+	   cpuWriteHandlersSet =0;
+   }
+}
+
 static void JYASIC_power(void)
 {
    unsigned int i;
@@ -386,8 +398,10 @@ static void JYASIC_power(void)
    SetWriteHandler(0xC000, 0xCFFF, writeIRQ);
    SetWriteHandler(0xD000, 0xD7FF, writeMode);    /* D800-DFFF ignored */
 
+   JYASIC_restoreWriteHandlers();
    for (i =0; i <0x10000; i++) cpuWriteHandlers[i] =GetWriteHandler(i);
    SetWriteHandler(0x0000, 0xFFFF, trapCPUWrite); /* Trap all CPU writes for IRQ clocking purposes */
+   cpuWriteHandlersSet =1;
 
    SetReadHandler(0x5000, 0x5FFF, readALU_DIP);
    SetReadHandler(0x6000, 0xFFFF, CartBR);
@@ -423,6 +437,7 @@ static void JYASIC_restore (int version)
 
 void JYASIC_init (CartInfo *info)
 {
+   cpuWriteHandlersSet =0;
    info->Reset = JYASIC_reset;
    info->Power = JYASIC_power;
    info->Close = JYASIC_close;
@@ -669,3 +684,114 @@ void Mapper421_Init(CartInfo *info)
 	sync =sync421;
 	JYASIC_init(info);
 }
+
+/* Mapper 394: HSK007 circuit board that can simulate J.Y. ASIC, MMC3, and NROM. */
+static uint8 HSK007Reg[4];
+void sync394 (void) /* Called when J.Y. ASIC is active */
+{
+	int prgAND =HSK007Reg[3] &0x10? 0x1F: 0x0F;
+	int chrAND =HSK007Reg[3] &0x80? 0xFF: 0x7F;
+	int prgOR  =HSK007Reg[3] <<1 &0x010 | HSK007Reg[1] <<5 &0x020;
+	int chrOR  =HSK007Reg[3] <<1 &0x080 | HSK007Reg[1] <<8 &0x100;
+	syncPRG(0x1F, prgOR);
+	syncCHR(0xFF, chrOR);
+	syncNT (0xFF, chrOR);	
+}
+static void Mapper394_PWrap(uint32 A, uint8 V)
+{
+	int prgAND =HSK007Reg[3] &0x10? 0x1F: 0x0F;
+	int prgOR  =HSK007Reg[3] <<1 &0x010 | HSK007Reg[1] <<5 &0x020;
+	if (HSK007Reg[1] &0x08)
+		setprg8(A, V &prgAND | prgOR &~prgAND);
+	else
+	if (A ==0x8000)
+		setprg32(A, (prgOR | HSK007Reg[3] <<1 &0x0F) >>2);
+	
+}
+static void Mapper394_CWrap(uint32 A, uint8 V)
+{
+	int chrAND =HSK007Reg[3] &0x80? 0xFF: 0x7F;
+	int chrOR  =HSK007Reg[3] <<1 &0x080 | HSK007Reg[1] <<8 &0x100;
+	setchr1(A, V &chrAND | chrOR &~chrAND);
+}
+static DECLFW(Mapper394_Write)
+{
+	uint8 oldMode =HSK007Reg[1];
+	A &=3;
+	HSK007Reg[A] =V;
+	if (A ==1)
+	{		
+		if (~oldMode &0x10 &&  V &0x10) JYASIC_power();
+		if ( oldMode &0x10 && ~V &0x10)
+		{
+			JYASIC_restoreWriteHandlers();
+			GenMMC3Power();
+		}
+	}
+	else
+	{
+		if (HSK007Reg[1] &0x10)
+			sync();
+		else
+		{
+			FixMMC3PRG(MMC3_cmd);
+			FixMMC3CHR(MMC3_cmd);
+		}
+			
+	}
+}
+static void Mapper394_restore (int version)
+{
+	int i;
+	JYASIC_restoreWriteHandlers();
+	if (HSK007Reg[1] &0x10)
+	{		
+		SetWriteHandler(0x5000, 0x5FFF, writeALU);
+		SetWriteHandler(0x6000, 0x7fff, CartBW);
+		SetWriteHandler(0x8000, 0x87FF, writePRG);     /* 8800-8FFF ignored */
+		SetWriteHandler(0x9000, 0x97FF, writeCHRLow);  /* 9800-9FFF ignored */
+		SetWriteHandler(0xA000, 0xA7FF, writeCHRHigh); /* A800-AFFF ignored */
+		SetWriteHandler(0xB000, 0xB7FF, writeNT);      /* B800-BFFF ignored */
+		SetWriteHandler(0xC000, 0xCFFF, writeIRQ);
+		SetWriteHandler(0xD000, 0xD7FF, writeMode);    /* D800-DFFF ignored */
+		
+		for (i =0; i <0x10000; i++) cpuWriteHandlers[i] =GetWriteHandler(i);
+		SetWriteHandler(0x0000, 0xFFFF, trapCPUWrite); /* Trap all CPU writes for IRQ clocking purposes */
+		cpuWriteHandlersSet =1;
+		
+		SetReadHandler(0x5000, 0x5FFF, readALU_DIP);
+		SetReadHandler(0x6000, 0xFFFF, CartBR);
+		sync();
+	}
+	else
+	{
+		SetWriteHandler(0x8000, 0xBFFF, MMC3_CMDWrite);
+		SetWriteHandler(0xC000, 0xFFFF, MMC3_IRQWrite);
+		SetReadHandler(0x8000, 0xFFFF, CartBR);
+		FixMMC3PRG(MMC3_cmd);
+		FixMMC3CHR(MMC3_cmd);
+	}
+}
+static void Mapper394_power(void)
+{
+	HSK007Reg[0] =0x00;
+	HSK007Reg[1] =0x0F;
+	HSK007Reg[2] =0x00;
+	HSK007Reg[3] =0x10;
+	GenMMC3Power();
+	SetWriteHandler(0x5000, 0x5FFF, Mapper394_Write);
+}
+
+void Mapper394_Init(CartInfo *info)
+{
+	allowExtendedMirroring =1;
+	sync =sync394;
+	JYASIC_init(info);
+	GenMMC3_Init(info, 128, 128, 0, 0);
+	pwrap =Mapper394_PWrap;
+	cwrap =Mapper394_CWrap;
+	info->Reset = Mapper394_power;
+	info->Power = Mapper394_power;
+	AddExState(HSK007Reg, 4, 0, "HSK ");
+	GameStateRestore = Mapper394_restore;
+}
diff --git a/src/ines.c b/src/ines.c
index 97ddef7..bdd384a 100644
--- a/src/ines.c
+++ b/src/ines.c
@@ -784,10 +784,11 @@ INES_BOARD_BEGIN()
 	INES_BOARD( "Realtec 8031",             390, Mapper390_Init         )
 	INES_BOARD( "BS-110",                   391, Mapper391_Init         )
 	INES_BOARD( "820720C",                  393, Mapper393_Init         )
+	INES_BOARD( "HSK007",                   394, Mapper394_Init         )
 	INES_BOARD( "Realtec 8210",             395, Mapper395_Init         )
-    INES_BOARD( "YY850437C",                396, Mapper396_Init         )
+	INES_BOARD( "YY850437C",                396, Mapper396_Init         )
 	INES_BOARD( "YY850439C",                397, Mapper397_Init         )
-	INES_BOARD( "BMC Super 19-in-1 (VIP19)", 401, Mapper401_Init         )
+	INES_BOARD( "BMC Super 19-in-1 (VIP19)",401, Mapper401_Init         )
 	INES_BOARD( "831019C J-2282",           402, J2282_Init             )
 	INES_BOARD( "89433",                    403, Mapper403_Init         )
 	INES_BOARD( "JY012005",                 404, Mapper404_Init         )
diff --git a/src/ines.h b/src/ines.h
index 7a568dd..e6ed97b 100644
--- a/src/ines.h
+++ b/src/ines.h
@@ -294,6 +294,7 @@ void Mapper389_Init(CartInfo *);
 void Mapper390_Init(CartInfo *);
 void Mapper391_Init(CartInfo *);
 void Mapper393_Init(CartInfo *);
+void Mapper394_Init(CartInfo *);
 void Mapper395_Init(CartInfo *);
 void Mapper396_Init(CartInfo *);
 void Mapper397_Init(CartInfo *);