Thank you, Bill Collier, for your note reminding me of the fun we had in those days (Summer 1968) when you taught and I attended hardware/software/architecture/programming classes.
From: William Collier<wwcollie...@gmail.com> Sent: Wednesday, November 2, 2022 11:27 AM To: Seymour J Metz Subject: BXLE instruction To: Seymour J Metz <sme...@gmu.edu<mailto:sme...@gmu.edu>> Hi, Last night I enjoyed reading your comment on the IBM-MAIN listserv: The slickest thing that I saw in OS/360 was code testing successive bits using BXH and BXLE. I would like to respond with the note below. I have followed (I believe) all the directions for creating a password in order to be allowed to post a note responding to your note. It hasn't worked (yet). Would you, in the interest of timeliness, be willing to post the note below on my behalf? If not, that's OK. I will figure it out. Bill Collier ============================== Re: End of several eras Back in 1965 IBM Poughkeepsie our job was to write an operating system for System/360 which would fit into 1K bytes (sic) of an 8k byte machine. I figured out how to use a BXLE instruction to both test and advance a bit string in a register. It saved us maybe 30-some bytes. I described this in IBM TR 00.1412-1, June 22, 1966. Thank you, Seymour Metz, for your note reminding us of the fun we had in those days. Bill Collier coll...@acm.org<mailto:coll...@acm.org> -- Gabriel Goldberg, Computers and Publishing, Inc. g...@gabegold.com 3401 Silver Maple Place, Falls Church, VA 22042 (703) 204-0433 LinkedIn: http://www.linkedin.com/in/gabegold Twitter: GabeG0 ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
