Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!ll-xn!ames!oliveb!felix!martin From: martin@felix.UUCP (Martin McKendry) Newsgroups: comp.unix.wizards,comp.arch Subject: Re: *Why* do modern machines mostly have 8-bit bytes? Message-ID: <3766@felix.UUCP> Date: Thu, 23-Jul-87 17:00:15 EDT Article-I.D.: felix.3766 Posted: Thu Jul 23 17:00:15 1987 Date-Received: Sat, 25-Jul-87 15:27:41 EDT References: <142700010@tiger.UUCP> <2792@phri.UUCP> <8315@utzoo.UUCP> <2807@phri.UUCP> Sender: daemon@felix.UUCP Reply-To: martin@felix.UUCP (Martin McKendry) Organization: FileNet Corp., Costa Mesa, CA Lines: 24 Xref: mnetor comp.unix.wizards:3415 comp.arch:1685 In article <2807@phri.UUCP> roy@phri.UUCP (Roy Smith) writes: > > First, why did older machines have all sorts of strange word >lengths -- 12, 36, and 60 being sizes that I know of, but I'm sure there >were others. >-- >Roy Smith, {allegra,cmcl2,philabs}!phri!roy >System Administrator, Public Health Research Institute >455 First Avenue, New York, NY 10016 Last year I was with Burroughs, doing a little work on the history of the A-series (B5500, etc). This machine has a 48-bit word. Turns out that it was set to 48 because at that time they thought characters were going to be 6 bits (we're talking 1957 here, folks), and they wanted a power-of-2 wordsize. Of course now they do these wonderful divide-by-3's to do character addressing (its word addressed). And, naturally, no true Burroughs hackers believe that there is any advantage to having a power-of-2 number of characters in a word. You ought to see the code and microcode executed to do Cobol! -- Martin S. McKendry FileNet Corp {hplabs,trwrb}!felix!martin