I would never use zero as it is fraught with dangers. Key0 is much more dangerous than supervisor state. So I never thought of it.
So it looks like key 0 is a special case for a subtask. On Mon, 27 Jan 2025 11:15:58 +0000 Seymour J Metz <[email protected]> wrote: :>ATTACH KEY=PROP | ZERO :> :>Note the restrictions in MVS Programming: Authorized Assembler Services Reference, Volume 1 (ALE-DYN), SA23-1372-60, for the privileged options. :> :>-- :>Shmuel (Seymour J.) Metz :>http://mason.gmu.edu/~smetz3 :>??? ?????????? ??? :>?????? ??????????? ???? ?????????? :> :> :> :>________________________________________ :>From: IBM Mainframe Discussion List <[email protected]> on behalf of Binyamin Dissen <[email protected]> :>Sent: Monday, January 27, 2025 1:19 AM :>To: [email protected] :>Subject: Re: Explanation of TCBPFK :> :>External Message: Use Caution :> :> :>Well, the PSW at abend should show they key it was in. Does it show zero? :> :>A PSW with key 0 still can get PIC-4 in DAT mode if the page or segment is :>protected (for example LPA pages). :> :>A PSW with key 0 can get a PIC 4 in either mode if modifying low storage :>without disabling low storage protection. :> :>Finally, your best way to get the TCB key you want is to put the program in :>the PPT and invoke it as a job step task. Not at all trivial to change on the :>fly. :> :> :>On Sun, 26 Jan 2025 20:57:47 -0500 Joseph Reichman :><[email protected]> wrote: :> :>:>Hi :>:> :>:>I am trying to hunt down a S0C4 pic 4 :>:> :>:>So I did a MODESET MODE=SUP,KEY=ZERO :>:> :>:>I ended up with the ABEND I stated :>:> :>:>My first question what exactly is TCBPFK used in my situation with executing the modeset :>:>The value of TCBPFK was X'80' :>:> :>:>Which the documentation says is user key :>:> :>:>My guess the modeset changed the value of the RBOPSW is there any way besides actually changing storage value of TCBPFK :>:> :>:>To change TCB key or I guess TCBPFK to zero :>:> :>:>Thanks :>:>---------------------------------------------------------------------- :>:>For IBM-MAIN subscribe / signoff / archive access instructions, :>:>send email to [email protected] with the message: INFO IBM-MAIN -- Binyamin Dissen <[email protected]> http://www.dissensoftware.com Director, Dissen Software, Bar & Grill - Israel ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
