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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
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