diff --git a/scsh/rdelim.scm b/scsh/rdelim.scm
index 3fddd6d..af5751d 100644
--- a/scsh/rdelim.scm
+++ b/scsh/rdelim.scm
@@ -155,13 +155,16 @@
 
 
 (define (port-buffer-read-delimited delims buf gobble? port start end)
+  (obtain-port-lock port)
   (let ((the-port-limit (port-limit port)))
     (let lp ((i start) (lp-port-index (port-index port))) 
       (cond ((port-pending-eof? port)
 	     (set-port-index! port lp-port-index)
-	     (values (eof-object) i))
+	     (release-port-lock port)
+	     (values (eof-object) (- i start)))
 	    ((>= i end)
 	     (set-port-index! port lp-port-index)
+	     (release-port-lock port)
 	     (values #f (- i start)))
 	    ((< lp-port-index the-port-limit)
 	     (let ((the-read-char 
@@ -172,13 +175,15 @@
 		     (if gobble? 
 			 (set-port-index! port (+ lp-port-index 1))
 			 (set-port-index! port lp-port-index))
+		     (release-port-lock port)
 		     (values the-read-char (- i start)))
 		   (begin
 		     (string-set! buf i the-read-char)
 		     (lp (+ i 1) (+ lp-port-index 1))))))
 	    (else  (set-port-index! port 0)
 		   (set-port-limit! port 0)
-		   (values 'port-buffer-exhausted i))))))
+		   (release-port-lock port)
+		   (values 'port-buffer-exhausted (- i start)))))))
 		 
 
 
@@ -195,44 +200,15 @@
 
     (let* ((delims (->char-set delims))
 	   (sdelims (char-set:s delims)))
-      
+      (let lp ((start start) (total 0))
       (receive (terminator num-read) 
 	       (port-buffer-read-delimited delims buf gobble? port start end)
 	       (if (not (eq? terminator 'port-buffer-exhausted))
-		   (values terminator num-read)
-		   (begin (set! start (+ start num-read))
-			  (if (fdport? port)
-	  ;; Direct C support for Unix file ports -- zippy quick.
-	  (let lp ((start start) (total num-read))
-	    (let ((fd (fdport-data:fd (fdport-data port))))
-	      (receive (terminator num-read)
-		       (%read-delimited-fd!/errno sdelims buf 
-						  fd start end)
-	        (let ((total (+ num-read total)))
-		  (cond ((char? terminator)
-			 (if (not gobble?) (push-back port terminator))
-			 (values terminator total))
-			((not (integer? terminator)) (values terminator total))
-			((= terminator errno/intr) 
-			 (lp (+ start num-read) total))
-			(else (errno-error terminator %read-delimited!
-					   num-read total
-					   delims buf gobble? port start end)))))))
+		   (values terminator (+ num-read total))
+		   (begin (peek-char port)  ; kludge to fill the buffer
+			  (lp (+ start num-read) (+ total num-read)))))))))
+			  
 
-	  ;; This is the code for other kinds of ports.
-	  ;; Mighty slow -- we read each char twice (peek first, then read).
-	  (let lp ((i start))
-	    (let ((c (peek-char port)))
-	      (cond ((or (eof-object? c)	; Found terminating char or eof
-			 (char-set-contains? delims c))
-		     (if gobble? (read-char port))
-		     (values c (- i start)))
-		    
-		    ((>= i end)			; Filled the buffer.
-		     (values #f (- i start)))
-		    
-		    (else (string-set! buf i (read-char port))
-			  (lp (+ i 1)))))))))))))
 
 ; overwrites port-index :-(
 (define (push-back port char)