Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!rutgers!sri-unix!sri-spam!ames!elroy!jplgodo!wlbr!scgvaxd!trwrb!cadovax!gryphon!richard From: richard@gryphon.CTS.COM (Richard Sexton) Newsgroups: talk.bizarre,comp.misc Subject: Re: What the world needs now...IBM 1130 nostalgia Message-ID: <892@gryphon.CTS.COM> Date: Tue, 7-Jul-87 00:33:20 EDT Article-I.D.: gryphon.892 Posted: Tue Jul 7 00:33:20 1987 Date-Received: Fri, 10-Jul-87 06:34:13 EDT References: <1240@ssc-vax.UUCP> <631@mapper.UUCP> Reply-To: richard@gryphon.CTS.COM (Richard Sexton) Followup-To: talk.bizzare Organization: Trailing Edge Technology, Redondo Beach, CA Lines: 68 Keywords: IBM 1130s Xref: mnetor talk.bizarre:2376 comp.misc:805 >I just wanted to put my $.02 memories on line also -- remember the printwheel >printer (I can't remember the model number)? When it did a line of The 1132 drum printer ? > >One of my compatriots signed some of his high-school yearbooks with a >five line assembler program to wipe the disk. This wasn't hard. Once, I filed the first 100 or so memory locations with zero, figuring I would see the Instruction Counter count up as it executed all these no-ops. I dont remember now if 0 was not a noop or not, but at any rate it wiped out the disk. Instant persona non grata. Guess this is a bit late to be reporting this bug. >I look at microprocessor specifications today (25MHz 68020, MIPS >chips, etc) and think back to 3 16-bit registers, LIBFs and CALLs, and >the everpopular XIO. Of course, booting was easy: turn the beast on, LIBF's, YEAH ! . . . LIBF ROUTINE . . . ROUTINE DC *-* <-- Wadda ya mean the RETURN ADDRESS get put here ?? . . Good stuff, Maynard ! (Background for you young pups) On the 1130 there was a button labeled 'Int Req' - interrupt request. When pressed it executed one of the five interrupts on the machine, supposidly to a routine that would flush to the next // JOB card. So why, oh why did IBM publish a program that showed you how to defeat this, by requiring a 16 bit code in the 'data-switches' to be present. Do you know what a 13 year old can do with this information ? Like empty the printer of all its paper. Or another one: there was a mode called 'Int Run' - Interrupt run. After every instruction a level 5 interrupt would occur. So we stuck a small loop and a return into memory with the switches and let 'er rip. When some luser, not in out good graces came along - poof! The mode dial got set to 'Int Run', and the poor bugger got to watch his program execute 10 times slower than everybody else. The real funny part would be when they would explain this to the teacher, and the teacher would do some song and dance about *why* the computer was doing this, all of it lies of course. He did'nt know a thing. Or how about the one where some &^*()@^ at IBM thought it would be a great trick to read stuff from the disk directly into location mumble-mumble, which served as index register 3. Do you have any idea what that does to a 13 year old mind ? No wonder we are all hacks. Cheers, -- Richard Sexton INTERNET: richard@gryphon.CTS.COM UUCP: {akgua, hplabs!hp-sdd, sdcsvax, ihnp4, nosc}!crash!gryphon!richard