diff -up ./include/dos_inc.h.orig ./include/dos_inc.h
--- ./include/dos_inc.h.orig	2015-12-27 12:43:12.000000000 -0800
+++ ./include/dos_inc.h	2015-12-27 11:53:19.000000000 -0800
@@ -170,7 +170,7 @@ void DOS_BuildUMBChain(bool umb_active,b
 bool DOS_LinkUMBsToMemChain(Bit16u linkstate);
 
 /* FCB stuff */
-bool DOS_FCBOpen(Bit16u seg,Bit16u offset);
+Bit16u DOS_FCBOpen(Bit16u seg,Bit16u offset);
 bool DOS_FCBCreate(Bit16u seg,Bit16u offset);
 bool DOS_FCBClose(Bit16u seg,Bit16u offset);
 bool DOS_FCBFindFirst(Bit16u seg,Bit16u offset);
diff -up ./src/dos/dos_classes.cpp.orig ./src/dos/dos_classes.cpp
diff -up ./src/dos/dos_files.cpp.orig ./src/dos/dos_files.cpp
--- ./src/dos/dos_files.cpp.orig	2015-12-27 10:08:26.000000000 -0800
+++ ./src/dos/dos_files.cpp	2015-12-27 12:22:17.000000000 -0800
@@ -964,7 +964,7 @@ bool DOS_FCBCreate(Bit16u seg,Bit16u off
 	return true;
 }
 
-bool DOS_FCBOpen(Bit16u seg,Bit16u offset) { 
+Bit16u DOS_FCBOpen(Bit16u seg,Bit16u offset) { 
 	DOS_FCB fcb(seg,offset);
 	char shortname[DOS_FCBNAME];Bit16u handle;
 	fcb.GetName(shortname);
@@ -972,7 +972,7 @@ bool DOS_FCBOpen(Bit16u seg,Bit16u offse
 	/* First check if the name is correct */
 	Bit8u drive;
 	char fullname[DOS_PATHLENGTH];
-	if (!DOS_MakeName(shortname,fullname,&drive)) return false;
+	if (!DOS_MakeName(shortname,fullname,&drive)) return (Bit16u)false;
 	
 	/* Check, if file is already opened */
 	for (Bit8u i=0;i<DOS_FILES;i++) {
@@ -982,16 +982,16 @@ bool DOS_FCBOpen(Bit16u seg,Bit16u offse
 			if (handle==0xFF) {
 				// This shouldnt happen
 				LOG(LOG_FILES,LOG_ERROR)("DOS: File %s is opened but has no psp entry.",shortname);
-				return false;
+				return (Bit16u)false;
 			}
 			fcb.FileOpen((Bit8u)handle);
-			return true;
+			return handle;
 		}
 	}
 	
 	if (!DOS_OpenFile(shortname,OPEN_READWRITE,&handle)) return false;
 	fcb.FileOpen((Bit8u)handle);
-	return true;
+	return handle;
 }
 
 bool DOS_FCBClose(Bit16u seg,Bit16u offset) {
@@ -1181,11 +1181,12 @@ bool DOS_FCBGetFileSize(Bit16u seg,Bit16
 	char shortname[DOS_PATHLENGTH];Bit16u entry;Bit8u handle;Bit16u rec_size;
 	DOS_FCB fcb(seg,offset);
 	fcb.GetName(shortname);
-	if (!DOS_OpenFile(shortname,OPEN_READ,&entry)) return false;
+	if (!(entry = DOS_FCBOpen(seg, offset))) return false;
 	handle = RealHandle(entry);
 	Bit32u size = 0;
 	Files[handle]->Seek(&size,DOS_SEEK_END);
-	DOS_CloseFile(entry);fcb.GetSeqData(handle,rec_size);
+	fcb.GetSeqData(handle,rec_size);
+	DOS_CloseFile(entry);
 	Bit32u random=(size/rec_size);
 	if (size % rec_size) random++;
 	fcb.SetRandom(random);