Thanks, Bob. I haven't used WAKEUP for many years, so I'll try it. David Wakser
-----Original Message----- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Bob Bates Sent: Tuesday, July 01, 2008 10:21 AM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: Best method Absolutely, Use the WAKEUP module. I have a program that waits for reader files and messages. The waiting part looks like: do forever 'WAKEUP +30 (RDR IUCVMSG' saverc = rc select when saverc = 4 then "process reader file" when saverc = 5 then "process a message" You might want to change the +30 if all it does is wait for reader files. See HELP WAKEUP for details