diff --git a/tcp-api/non-os2-3.rkt b/tcp-api/non-os2-3.rkt
index 44da843..182f886 100644
--- a/tcp-api/non-os2-3.rkt
+++ b/tcp-api/non-os2-3.rkt
@@ -7,7 +7,7 @@
     (thread (connection-handler cin cout))
     (loop)))
 
-(define (connection-handler cin cout)
+(define ((connection-handler cin cout))
   (let connection-loop ()
     (define v (read-byte cin))
     (unless (or (eof-object? v) (equal? v #"\4"))
diff --git a/tcp-api/os2-tcp-test-echo-service-2.rkt b/tcp-api/os2-tcp-test-echo-service-2.rkt
index 70d6723..45c62eb 100644
--- a/tcp-api/os2-tcp-test-echo-service-2.rkt
+++ b/tcp-api/os2-tcp-test-echo-service-2.rkt
@@ -13,9 +13,9 @@
     (role/act in-topic
       [(tcp-channel _ _ (or (== #"\4") (? eof-object?)))
        (kill)]
-      [(tcp-channel _ _ (? bytes? line))
+      [(tcp-channel _ _ (? bytes? bytev))
        (list (cin (tcp-credit 1) #:mode 'feedback)
-	     (cout line))])))
+	     (cout bytev))])))
 
 (define (main port)
   (ground-vm
@@ -25,6 +25,24 @@
 
 (main 5999)
 
+(define (tcp-accept topic)
+  (match-define (topic (tcp-channel remote-addr local-addr _)) topic)
+  (values (match-lambda
+	    [(val #:mode 'feedback)
+	     (send-feedback (tcp-channel remote-addr local-addr val))])
+	  (match-lambda
+	    [(val)
+	     (send-message (tcp-channel local-addr remote-addr val))])
+	  (topic-subscriber (tcp-channel remote-addr local-addr (wild)))
+	  (topic-publisher (tcp-channel local-addr remote-addr (wild)))))
+
+
+(define (tcp-listener port)
+  (topic-subscriber (tcp-channel (wild)
+				 (tcp-local-endpoint port)
+				 (wild))
+		    #:monitor? #t))
+
 (require racket/string)
 (require racket/set)
 (require racket/match)