IIRC, the DIRF bit was implemented because of a problem in DADSM causing overlapping tracks on 2314 volumes in a shared DASD environment with 2 controllers (2314 & 2844). I was playing systems programmer at NIH in the late '60s thru the early '80s and we ran into the problem with horrific results. We were fortunate to have, as a result of a SEV-1 incident, some of the best DASDM folks on-site for several weeks trying to reproduce/trap the situation. These folks implemented the first version of DIRF, to serialize updating of the F5 stuff. I believe this was known as the "ping-pong" problem.
I have remained close friends with two of these folks (long since retired from IBM). On 5/11/07, Mark H. Young <[EMAIL PROTECTED]> wrote:
On Thu, 10 May 2007 10:42:18 -0400, John Eells <[EMAIL PROTECTED]> wrote: >The IBM Jargon Dictionary confirms my recollection that it came >from "Change Label Information Program." > >http://www.comlay.net/ibmjarg.pdf > >-- >John Eells >z/OS Technical Marketing >IBM Poughkeepsie >[EMAIL PROTECTED] > That IBM *jargon dictionary* is GREAT. But it lacks one important def from *back-in-the-day* ???? DIRF bit = DASDM Interrupt Recording Facility bit Anyone remember that one?! Looks like a revision is in order?! ...mhyI ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
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