RS-232 OPEN/CLOSE connected to I/O stack

c64/kernal/iec/open_iec.s

@@ -9,6 +9,10 @@
 
 open_iec:
 
+	// Check for command to send
+	ldy FNLEN
+	beq open_iec_done
+
 	// We have a command to send to IEC device
 	jsr LISTEN
 	bcc !+
@@ -28,6 +32,8 @@ open_iec:
 	// Send command ('file name')
 	jsr lvs_send_file_name
 
+open_iec_done:
+
 	jmp open_done_success