diff --git a/include/dos_inc.h b/include/dos_inc.h
index b2d2b868..43ba1d15 100644
--- a/include/dos_inc.h
+++ b/include/dos_inc.h
@@ -97,6 +97,7 @@ bool DOS_GetFileDate(Bit16u entry, Bit16u* otime, Bit16u* odate);
 
 /* Routines for Drive Class */
 bool DOS_OpenFile(char * name,Bit8u flags,Bit16u * entry);
+bool DOS_OpenFileExtended(char *name, Bit16u flags, Bit16u createAttr, Bit16u action, Bit16u *entry, Bit16u* status);
 bool DOS_CreateFile(char * name,Bit16u attribute,Bit16u * entry);
 bool DOS_UnlinkFile(char * name);
 bool DOS_FindFirst(char *search,Bit16u attr);
diff --git a/src/dos/dos.cpp b/src/dos/dos.cpp
index c7c548a6..fc6da360 100644
--- a/src/dos/dos.cpp
+++ b/src/dos/dos.cpp
@@ -833,7 +833,13 @@ static Bitu DOS_21Handler(void) {
 			break;
 		} 
 	case 0x6c:					/* Extended Open/Create */
-		E_Exit("Unhandled Dos 21 call %02X",reg_ah);
+		MEM_StrCopy(SegPhys(ds)+reg_si,name1,DOSNAMEBUF);
+		if (DOS_OpenFileExtended(name1,reg_bx,reg_cx,reg_dx,&reg_ax,&reg_cx)) {
+			CALLBACK_SCF(false);
+		} else {
+			reg_ax=dos.errorcode;
+			CALLBACK_SCF(true);
+		}
 		break;
 	case 0x71:					/* Unknown probably 4dos detection */
 		reg_ax=0x7100;
diff --git a/src/dos/dos_files.cpp b/src/dos/dos_files.cpp
index a5babc4b..95f7ae07 100644
--- a/src/dos/dos_files.cpp
+++ b/src/dos/dos_files.cpp
@@ -370,6 +370,32 @@ bool DOS_OpenFile(char * name,Bit8u flags,Bit16u * entry) {
 	}
 }
 
+bool DOS_OpenFileExtended(char *name, Bit16u flags, Bit16u createAttr, Bit16u action, Bit16u *entry, Bit16u* status)
+// FIXME: Not yet supported : Bit 13 of flags (int 0x24 on critical error
+{
+	Bit16u result = 0;
+	if (DOS_OpenFile(name, flags, entry)) {
+		// File already exists
+		switch (action & 0x0f) {
+			case 0x00 : return false;			// failed
+			case 0x01 :	result = 1; break;		// file open (already done)
+			case 0x02 : DOS_CloseFile(*entry);	// replace
+						if (!DOS_CreateFile(name, flags, entry)) return false;
+						result = 3;
+						break;
+			default	  : E_Exit("DOS: OpenFileExtended: Unknown action.");
+		};
+	} else {
+		// File doesnt exist
+		if ((action & 0xf0)==0) return false;
+		// Create File
+		if (!DOS_CreateFile(name, flags, entry)) return false;
+		result = 2;
+	};
+	*status = result;
+	return true;
+};
+
 bool DOS_UnlinkFile(char * name) {
 	char fullname[DOS_PATHLENGTH];Bit8u drive;
 	if (!DOS_MakeName(name,fullname,&drive)) return false;