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From: dougf@dougf.Caltech.Edu (Doug Freyburger)
Newsgroups: rec.humor,rec.humor.d,comp.misc
Subject: Re: Looking for Computer Folklore
Message-ID: <9463@cit-vax.Caltech.Edu>
Date: 8 Feb 89 23:48:08 GMT
References: <799@n8emr.UUCP> <6255@saturn.ucsc.edu>
Sender: news@cit-vax.Caltech.Edu
Reply-To: dougf@wega.caltech.edu (Doug Freyburger)
Organization: California Institute of Technology
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In article <6255@saturn.ucsc.edu> haynes@ucscc.UCSC.EDU (Jim Haynes) writes:
>
>I had occasion to look at the date routines in an early version of the
>operating system for the Burroughs 6500.  Not only did it take care of
>leap years every four years; it correctly handled the exceptions for
>centuries and millenia.  If you're going to write software that is
>correct, you might as well write it to be correct for the next few
>thousand years.  I guess you don't worry about the extra computation if
>it's only executed once a day.
>haynes@ucscc.ucsc.edu

	My office-mate years ago at JPL lived through this:
When the Viking Mars probes where launched, noone thought they'd
last very long in Mars oribt, so the programs saved a few bytes
by ignoring leap years and hardwiring 366 in (1976 was leap).
The next year everyone was called in to rewrite their systems
for downloading to Mars with a 365 day year.  Better yet, both
spacecraft were still going strong in 1980 and most of the crew
were long gone to other projects.  Everyone had to be called
back for another download to Mars.  It pays to include leap year
into your code.

	From personal experience:
I remember a Lunar-Lander game written in PDP-11 TECO that used
VT100 cursor keys.  The entire program looked like your terminal
was at the wrong baud rate (standard TECO programming form).  It
ran without change on the old PDP-10 still surviving at college
and later on the brand-new VAX as well as 3 different O/S versions
of PDP-11 without change.

	From rumors of ancient DEC history:
The system programmer group writing TOPS-10 used to love fancy
TECO programs and had a weekly contest for them.  One guru working
on ForTran compilers would read them carefully but never enter one.
They thought he was just concentrating on compilers.  Then one week
he submitted a macro that did ForTran compilation, complete with
optimization.  The TECO program took days to run, but it worked.
Apparently he had written a PDP-10 instruction set emulator in
TECO and feed the compiler to it!
dougf@wega.caltech.edu

Douglas J Freyburger
Caltech 206-49
Pasadena, CA 91125

(818)356-2913