diff --git a/c64/kernal/listen.s b/c64/kernal/listen.s
index 4fc90f42..53dbd21e 100644
--- a/c64/kernal/listen.s
+++ b/c64/kernal/listen.s
@@ -1,3 +1,7 @@
 ; Function defined on pp272-273 of C64 Programmers Reference Guide
+
 listen:
-	rts
+
+	;; This trivial routine is documented in 'Compute's Mapping the Commodore 64', page 223
+	ora $20
+	jmp iec_tx_byte
diff --git a/c64/kernal/talk.s b/c64/kernal/talk.s
index 48a341d6..a51faf8b 100644
--- a/c64/kernal/talk.s
+++ b/c64/kernal/talk.s
@@ -1,3 +1,7 @@
 ; Function defined on pp272-273 of C64 Programmers Reference Guide
+
 talk:
-	rts
+
+	;; This trivial routine is documented in 'Compute's Mapping the Commodore 64', page 223
+	ora $40
+	jmp iec_tx_byte
diff --git a/c64/kernal/unlsn.s b/c64/kernal/unlsn.s
index 31a35a40..c3854f7c 100644
--- a/c64/kernal/unlsn.s
+++ b/c64/kernal/unlsn.s
@@ -1,3 +1,7 @@
 ; Function defined on pp272-273 of C64 Programmers Reference Guide
+
 unlsn:
-	rts
+
+	;; This trivial routine is documented in 'Compute's Mapping the Commodore 64', page 224
+	lda $5F
+	jmp iec_tx_byte
diff --git a/c64/kernal/untlk.s b/c64/kernal/untlk.s
index 30a018a4..275adbaa 100644
--- a/c64/kernal/untlk.s
+++ b/c64/kernal/untlk.s
@@ -1,3 +1,7 @@
 ; Function defined on pp272-273 of C64 Programmers Reference Guide
+
 untlk:
-	rts
+
+	;; This trivial routine is documented in 'Compute's Mapping the Commodore 64', page 224
+	lda $5F
+	jmp iec_tx_byte