Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!husc6!spdcc!merk!alliant!linus!mbunix!eachus
From: eachus@mbunix.mitre.org (Robert Eachus)
Newsgroups: comp.object
Subject: Re: OOD applied to interpreters and compilers
Summary: This has gone far enough....
Keywords: old times, Univac I, ENIAC
Message-ID: <74864@linus.UUCP>
Date: 20 Oct 89 23:28:35 GMT
References: <5226@cbnewsm.ATT.COM> <8721@goofy.megatest.UUCP> <15367@vlsisj.VLSI.COM>
Sender: news@linus.UUCP
Reply-To: eachus@mbunix.mitre.org (Robert I. Eachus)
Distribution: usa
Organization: The MITRE Corporation, Bedford, Mass.
Lines: 60

In article <15367@vlsisj.VLSI.COM> davidc@vlsisj.UUCP (David Chapman) writes:
>In article <8721@goofy.megatest.UUCP> djones@megatest.UUCP (Dave Jones) writes:
><From article <5226@cbnewsm.ATT.COM>, by nsw@cbnewsm.ATT.COM (Neil Weinstock):
><> Yeah, I once did something similar, but in Vax microcode.  The hard part was
><> typing it in hex...

><Typing it? TYPING IT? You kids got it too easy today. When I was your
><age, we used to enter the operating system into core each morning using
><the toggle switches on the front panel.

>You had an operating system?  Oh how I wished I could have one when I was
>younger...

>And just be glad you had core instead of mercury delay lines!
>-- 
>		David Chapman

     This has gone far enough (well almost :-)...

     Mercury delay lines? Sounds like a Univac I or EDVAC.  REAL old
timers can tell you about programming the ENIAC using rotary switches.
(Or programming an IBM 403 {Yetch! Acch! Pfft!} or a Burroughs E-101
using plugboards.)  The first time I saw RPG-II, it looked vaguely
familiar, I finally realized that it was originally designed to allow
reuse of old IBM 403 plugboard programs.  Or isn't that the kind of
software reuse you had in mind....

     Seriously, although I never programmed the ENIAC, when the HP-55
came out (yes, the handheld programmable calculator), my father and I
dug out some old ENIAC code, since the architectures were so similar,
and did some comparative benchmarks.  The HP-55 weighed in at 50 times
the speed of the ENIAC, cost a lot less, and was much more portable.

    The most smallest and most ancient machine for which I ever
attempted a parser and code generator was a Royal-McBee RPG 4000 with
24-bit words and a 8000-odd word drum memory.  (The last few tracks
stored eight words each but they came around eight times as fast due
to the creative use of additional read and write heads.)  Input-output
was paper tape and console switches and console switches ONLY.  (The
display was an oscilloscope trace for the register contents, no
blinking lights even.)  Made debugging real fun.  Code "patches to a
program were done by splicing or creative use of Scotch tape and a
hole punch, and when I was working on a bootstrap loader our
Frieden Flexowriter's punch was broken, so...

     I wrote a bootstrap loader for an RPG-4000...AND HAND PUNCHED IT
INTO THE PAPER TAPE!  (It was about fifty words long, written in hex
so that I could put key entry points in words with the "right"
address.  This allowed us to hook the Flexowriter up directly to the
machine and type things like LOAD PUNCH.  Woopie!)  We sure have it
easy nowadays.

     I would have directed followups to comp.history.ancient, but as
far as I know, those machines are not connected to Internet.

					Robert I. Eachus

with STANDARD_DISCLAIMER;
use  STANDARD_DISCLAIMER;
function MESSAGE (TEXT: in CLEVER_IDEAS) return BETTER_IDEAS is...