As I recall, this dates back to the beginnings of TSO under MVT. As I recall the story, the original (perhaps unreleased) version of TSO did allow multiple signons to a single id. But there was some sort of problem having to do with how to CANCEL a given session, or how to SEND a message to a particular session. Back in the MVT days, the CANCEL command did not have a way to direct the CANCEL to a given region (as the A= does to a given address space today). So if you had an id signed on 3 times with only 1 of them "having a problem", then a CANCEL U=thisid would cancel all 3 sessions. The same happened with started tasks and batch jobs. Oh, and I think there was also a problem with the TIOC sending command output to the wrong terminal. I.e. enter the LISTALC command on terminal#1 and the results might go to terminal#2 instead. But I'm real vague on that last one.
This is likely not a problem in today's environment. But IBM is deprecating the use of interactive TSO for using PCs interacting with z/OS using RD/z. Why? Likely because it is more powerful and much more profitable. Fixing TSO is probably like trying to build a road through a mine field of unexploded ordinance. On Wed, Jan 29, 2014 at 3:44 PM, Frank Swarbrick <[email protected]>wrote: > Is there some actual technical reason why TSO cannot be made to allow one > user ID to log in multiple times to TSO within a single LPAR? > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN > -- Wasn't there something about a PASCAL programmer knowing the value of everything and the Wirth of nothing? Maranatha! <>< John McKown ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
