diff --git a/sources/COREIO b/sources/COREIO
index 72ff5f56..be878489 100644
--- a/sources/COREIO
+++ b/sources/COREIO
@@ -1,12 +1,12 @@
-(DEFINE-FILE-INFO PACKAGE "INTERLISP" READTABLE "INTERLISP" BASE 10)
+(DEFINE-FILE-INFO :PACKAGE "INTERLISP" :READTABLE "INTERLISP" :BASE 10)
 
-(FILECREATED "11-Sep-2025 16:49:07" {WMEDLEY}<sources>COREIO.;18 56903  
+(FILECREATED "28-Feb-2026 12:09:38" {WMEDLEY}<sources>COREIO.;20 57201  
 
       :EDIT-BY rmk
 
       :CHANGES-TO (FNS \CORE.DIRECTORYNAMEP)
 
-      :PREVIOUS-DATE " 5-Jun-2022 00:14:07" {WMEDLEY}<sources>COREIO.;17)
+      :PREVIOUS-DATE "11-Sep-2025 16:49:07" {WMEDLEY}<sources>COREIO.;18)
 
 
 (PRETTYCOMPRINT COREIOCOMS)
@@ -89,6 +89,8 @@
 (\CORE.DIRECTORYNAMEP
   [LAMBDA (DIRNAME DEV)
 
+    (* ;; "Edited 28-Feb-2026 12:08 by rmk")
+
     (* ;; "Edited 11-Sep-2025 16:48 by rmk")
 
     (* ;; "Edited 18-Jan-2022 11:17 by rmk")
@@ -106,18 +108,21 @@
 
         (* ;; "Returns NIL for a DIRNAME of just {CORE},  or {CORE}xxx.  If the latter, then we want it to be a directory and not a file  (assuming that xxx and xxx> can't both exist.")
 
-        [LET [(DIR (FILENAMEFIELD DIRNAME 'DIRECTORY]
-             (CL:WHEN DIR
-                 (SETQ DIR (CONCAT DIR ">"))
+        (LET [(DIR (FILENAMEFIELD DIRNAME 'DIRECTORY]
+             (if DIR
+                 then (SETQ DIR (CONCAT DIR ">")) 
 
-                 (* ;; "DIRPOS because caller may not have stripped off the device. This will match the first < or / (or >)")
+                      (* ;; "DIRPOS because caller may not have stripped off the device. This will match the first < or / (or >)")
 
-                 (FOR ENTRY (DIRPOS _ (STRPOS "<" DIRNAME 1 NIL NIL NIL FILEDIRCASEARRAY))
-                    FIRST (CL:UNLESS (EQ DIRPOS 1)
-                              (SETQ DIRNAME (SUBSTRING DIRNAME DIRPOS)))
-                    IN (CDR (FETCH COREDIRECTORY OF DEV))
-                    WHEN (STRPOS DIRNAME (CAR ENTRY)
-                                1 NIL T NIL FILEDIRCASEARRAY) DO (RETURN T)))])])
+                      (FOR ENTRY (DIRPOS _ (STRPOS "<" DIRNAME 1 NIL NIL NIL FILEDIRCASEARRAY))
+                         FIRST (CL:UNLESS (EQ DIRPOS 1)
+                                   (SETQ DIRNAME (SUBSTRING DIRNAME DIRPOS)))
+                         IN (CDR (FETCH COREDIRECTORY OF DEV))
+                         WHEN (STRPOS DIRNAME (CAR ENTRY)
+                                     1 NIL T NIL FILEDIRCASEARRAY) DO (RETURN T))
+               else                                          (* ; 
+                                          "Top level: does the device exist at al. The cd {CORE}case")
+                    T)))])
 
 (\CORE.FINDPAGE
   [LAMBDA (STREAM PN)                                    (* bvm%: "20-Apr-85 13:32")
@@ -997,16 +1002,16 @@
 )
 )
 (DECLARE%: DONTCOPY
-  (FILEMAP (NIL (1572 46115 (\CORE.CLOSEFILE 1582 . 2355) (\CORE.DELETEFILE 2357 . 4343) (
-\CORE.DIRECTORYNAMEP 4345 . 5838) (\CORE.FINDPAGE 5840 . 9069) (\CORE.GENERATEFILES 9071 . 11658) (
-\CORE.NEXTFILEFN 11660 . 12159) (\CORE.FILEINFOFN 12161 . 12390) (\CORE.GETFILEHANDLE 12392 . 14546) (
-\CORE.GETFILEINFO 14548 . 15511) (\CORE.GETFILEINFO.FROM.INFOBLOCK 15513 . 17050) (\CORE.GETFILENAME 
-17052 . 19341) (\CORE.GETINFOBLOCK 19343 . 21966) (\CORE.NAMESCAN 21968 . 23515) (\CORE.NAMESEGMENT 
-23517 . 23954) (\CORE.OPENFILE 23956 . 27348) (\COREFILE.SETPARAMETERS 27350 . 29531) (
-\CORE.PACKFILENAME 29533 . 29928) (\CORE.RELEASEPAGES 29930 . 30531) (\CORE.SETFILEPTR 30533 . 31632) 
-(\CORE.UPDATEOF 31634 . 33263) (\CORE.BACKFILEPTR 33265 . 35473) (\CORE.SETEOFPTR 35475 . 37344) (
-\CORE.SETACCESSTIME 37346 . 37971) (\CORE.SETFILEINFO 37973 . 40275) (\CORE.GETNEXTBUFFER 40277 . 
-44233) (\CORE.UNPACKFILENAME 44235 . 46113)) (46116 49749 (COREDEVICE 46126 . 46297) (
-\CREATECOREDEVICE 46299 . 49747)) (49750 52164 (\NODIRCOREFDEV 49760 . 50357) (\NODIRCORE.OPENFILE 
-50359 . 52162)))))
+  (FILEMAP (NIL (1572 46413 (\CORE.CLOSEFILE 1582 . 2355) (\CORE.DELETEFILE 2357 . 4343) (
+\CORE.DIRECTORYNAMEP 4345 . 6136) (\CORE.FINDPAGE 6138 . 9367) (\CORE.GENERATEFILES 9369 . 11956) (
+\CORE.NEXTFILEFN 11958 . 12457) (\CORE.FILEINFOFN 12459 . 12688) (\CORE.GETFILEHANDLE 12690 . 14844) (
+\CORE.GETFILEINFO 14846 . 15809) (\CORE.GETFILEINFO.FROM.INFOBLOCK 15811 . 17348) (\CORE.GETFILENAME 
+17350 . 19639) (\CORE.GETINFOBLOCK 19641 . 22264) (\CORE.NAMESCAN 22266 . 23813) (\CORE.NAMESEGMENT 
+23815 . 24252) (\CORE.OPENFILE 24254 . 27646) (\COREFILE.SETPARAMETERS 27648 . 29829) (
+\CORE.PACKFILENAME 29831 . 30226) (\CORE.RELEASEPAGES 30228 . 30829) (\CORE.SETFILEPTR 30831 . 31930) 
+(\CORE.UPDATEOF 31932 . 33561) (\CORE.BACKFILEPTR 33563 . 35771) (\CORE.SETEOFPTR 35773 . 37642) (
+\CORE.SETACCESSTIME 37644 . 38269) (\CORE.SETFILEINFO 38271 . 40573) (\CORE.GETNEXTBUFFER 40575 . 
+44531) (\CORE.UNPACKFILENAME 44533 . 46411)) (46414 50047 (COREDEVICE 46424 . 46595) (
+\CREATECOREDEVICE 46597 . 50045)) (50048 52462 (\NODIRCOREFDEV 50058 . 50655) (\NODIRCORE.OPENFILE 
+50657 . 52460)))))
 STOP
diff --git a/sources/COREIO.LCOM b/sources/COREIO.LCOM
index f011a7be..5c3f58cc 100644
Binary files a/sources/COREIO.LCOM and b/sources/COREIO.LCOM differ
