The World of Computer Software/World_Of_Computer_Software-02-387-Vol-3of3.iso/0/0393afc.zip/AFC-FAQ.1

Text File | 1993-03-10 | 21KB | 495 lines

Article #38859 (38954 is last):
From: [e-mail] (Wilson Roberto Afonso)
Newsgroups: alt.folklore.computers
Subject: alt.folklore.computers FAQ - Part 01
Date: Tue Mar  9 09:41:40 1993


Archive-name: afc-faq-1
Last-modified: 04-Mar-1993

This is the alt.folklore.computers list of Frequently Asked Questions
(FAQ).  It is maintained by Wilson Afonso ([e-mail])  All
contributions and corrections are welcome, but I'm ultimately
responsible for what appears here.  Contributors are acknowledged, if
possible.

This is a three-part file.  The first part contains mostly generic questions.
The second is a small hitory of computers, and the third is a list of books
which are more or less related to computer folklore.

File 1 (this file):
I   - Introduction
II  - Generic questions
III - General folklore
IV  - Origins
V   - Firsts
VI  - Jokes
VII - Net Resources
VIII- Acknowledgement
IX  - Things I am looking for

File 2:
X   - A Chronology of Digital Computing Machines (to 1952)

File 3:
XI  - List of computer-folklore related books


 -------------------------------------------------------------------------

I - Introduction

1 - What is folklore ?

According to Webster's:
               Folklore: 1. Traditional customs, tales, or sayings
                 preserved orally among a people. 2. A comparative
                 science that investigates the life and spirit  of
                 a people as revealed in their folklore [recursive
                 definition?] 3. A widely held unsupported specious
                 notion or body of notions

In this newsgroup, all of the definitions above seem to be supported.
One can say that discussions in this group approach discussion about
history of computation, but that is not quite right.  Ultimately, the
difference between history and folklore is that history deals with
great and important facts and folklore deals with minor, day-to-day
facts.  We obviously discuss facts that fit in "History", too, but
that is a side-effect of the overall discussion.


II - Generic questions

II.1 - What is the origin of the term XXX ?  What does XXX mean ?

Answer to questions like this can be found in a big (I mean it!) file
called The Jargon File.  This file contains, among other things, the
meaning of thousands of words used by computers people.  If you ever
heard of a computer-related word, it is probably in this file.  Be
aware, however, that this file is not a lexicon of technical terms.
It mostly contains words that you _don't_ find in computer dictionaries.
You can get it by anonymous ftp, in prep.ai.mit.edu (18.71.0.38), in
directory pub/gnu, as the file named jargon2911.ascii.Z  Its size is 507845
bytes (compressed), and uncompresses to a file with 1125880 bytes.  It is
also a published book, _The New Hacker's Dictionary_ (see below, question II.3).


II.2 - Is {famous person} on the net?

There is also a file with information on it.  It was posted to a.f.c
in Feb. 26th, 1993.  As far as I know, it is not in any FTP site, and
I don't know if it is being updated.  More information on it as soon as
I get it.


II.3 - What are some good books on computer folklore?

Look at the third file of this FAQ.  It contains a large list of such books.


II.4 - Where can I find {interesting file} ?

Try archie.  But, sometimes it is really difficult to know the name of
the file, even if you know the title of the article.  I include a small
list below:

- 'Why Pascal is Not My Favorite Programming Language', by Brian Kernighan :
it was posted to a.f.c. as ASCII.  It is also available as a PostScript file
in research.att.com:netlib/toms/100.Z

- 'Real Programmers don't use Pascal', by Ed Post: it was posted to a.f.c, too.
It is available via FTP from leif.thep.lu.se (130.235.92.55) as
pub/Misc/realprog

- 'The Tao of Programming': it is copyrighted material, so it cannot be
distributed via FTP.  Anyway, it was posted to a.f.c in Feb. 1993.

- This FAQ: by now, nowhere.  I will see to it.



III - General folklore

III.1 - I heard that one of the NASA space probes went off course and
        had to be destroyed because of a typo in a FORTRAN DO loop.
        Is there any truth to this rumor?

The probe was Mariner I.  Intended to be the first US spacecraft to visit
another planet, it was destroyed by a range officer on 22 July 1962 when
it behaved erratically four minutes after launch.  But the problem was not
a DO loop.  This is what happened:

| #  During the launch the Atlas booster rocket was guided with the help
| #  of two radar systems.  One, the Rate System, measured the velocity of
| #  the rocket as it ascended through the atmosphere.  The other, the
| #  Track System, measured its distance and angle from a tracking
| #  antenna near the launch site.  At the Cape a guidance computer
| #  processed these signals and sent control signals back to the
| #  tracking system, which in turn sent signals to the rocket.  Its
| #  primary function was to ensure a proper separation from the Atlas
| #  booster and ignition of the Agena upper stage, which was to carry
| #  the Mariner Spacecraft to Venus.
| #
| #  Timing for the two radar systems was separated by a difference of
| #  forty-three milliseconds.  To compensate, the computer was instructed
| #  to add forty-three milliseconds to the data from the Rate System
| #  during the launch.  This action, which set both systems to the same
| #  sampling time base, required smoothed, or averaged, track data,
| #  obtained by an earlier computation, not the raw velocity data
| #  relayed directly from the track radar.  The symbol for this smoothed
| #  data was ... `R dot bar n' [R overstruck `.' and `_' and subscript n],
| #  where R stands for the radius, the dot for the first derivative
| #  (i.e., the velocity), the bar for smoothed data, and n for the
| #  increment.
| #
| #  The bar was left out of the hand-written guidance equations.  [A
| #  footnote cites interviews with John Norton and General Jack Albert.]
| #  Then during launch the on-board Rate System hardware failed.  That in
| #  itself should not have jeopardized the mission, as the Track System
| #  radar was working and could have handled the ascent.  But because of
| #  the missing bar in the guidance equations, the computer was
| #  processing the track data incorrectly.  [Paul's EndNote amplifies:
| #  The Mariner I failure was thus a {\it combination} of a hardware
| #  failure and the software bug.  The same flawed program had been used
| #  in several earlier Ranger launches with no ill effects.]  The result
| #  was erroneous information that velocity was fluctuating in an
| #  erratic and unpredictable manner, for which the computer tried to
| #  compensate by sending correction signals back to the rocket.  In fact
| #  the rocket was ascending smoothly and needed no such correction.  The
| #  result was {\it genuine} instead of phantom erratic behavior, which
| #  led the range safety officer to destroy the missile, and with it the
| #  Mariner spacecraft.  Mariner I, its systems functioning normally,
| #  plunged into the Atlantic.

But there was also a problem with a DO loop.  This is the history, as told by
Fred Webb in alt.folklore.computers in 1990:

|  I worked at Nasa during the summer of 1963.  The group I was working
|  in was doing preliminary work on the Mission Control Center computer
|  systems and programs.  My office mate had the job of testing out an
|  orbit computation program which had been used during the Mercury
|  flights.  Running some test data with known answers through it, he was
|  getting answers that were close, but not accurate enough.  So, he
|  started looking for numerical problems in the algorithm, checking to
|  make sure his tests data was really correct, etc.
|
|  After a couple of weeks with no results, he came across a DO
|  statement, in the form:
|       DO 10 I=1.10
|  This statement was interpreted by the compiler (correctly) as:
|       DO10I = 1.10
|  The programmer had clearly intended:
|       DO 10 I = 1, 10
|
|  After changing the `.' to a `,' the program results were correct to
|  the desired accuracy.  Apparently, the program's answers had been
|  "good enough" for the sub-orbital Mercury flights, so no one suspected
|  a bug until they tried to get greater accuracy, in anticipation of
|  later orbital and moon flights.  As far as I know, this particular bug
|  was never blamed for any actual failure of a space flight, but the
|  other details here seem close enough that I'm sure this incident is the
|  source of the DO story.




III.2 - I heard that Gary Kildall missed the chance to make CP/M the
        IBM PC operating system because he decided to go flying on
        the day the IBM reps had an appointment.  Is this true?

I am not sure by now.  I am waiting for somebody who seems to know the
history to tell me.


III.3 - Is there really a coke machine attached to the Internet?

They say so.  Actually, it's address is coke.elab.cs.cmu.edu (128.2.209.43).
It cannot be fingered every time (sometimes it refuses connection, and
sometimes it answers an empty line).  They seem to be still working in the
software, and the format of the information is probable to change.  But, if
you finger it today, the information you get back is something like this :

wilson@tatu 21 % finger @coke.elab.cs.cmu.edu
[coke.elab.cs.cmu.edu]
WARNING: This software still contains at least one bug!
Coke Server Ver 0.99 2-26-93
Information may not be correct, use at your own risk.
Coke:           Cold:  10   Warm:   0          Buttons
Diet coke:      Cold:   6   Warm:   0        C: EMPTY
Sprite:         Cold:   2   Warm:   0    C: COLD    D: EMPTY
                                         C: COLD    D: COLD
                                         C: EMPTY   D: COLD
                                                    C: COLD
                                                    S: COLD

wilson@tatu 22 % finger [e-mail]
[coke.elab.cs.cmu.edu]
WARNING: This software still contains at least one bug!
Coke Server Ver 0.99 2-26-93
    M & M                      Buttons
   /-----\          C: CCCCCCCCCC................
   |*****|        C: CCCCCCCCC....  D: CCCCCCCC.....
   |*****|        C: CCCCCCCCC....  D: CCCCCCCCCC...
   |*****|        C: CCCCCCCCCC...  D: CCCCCCCCCCC..
   |*****|                          C: CCCCCCCCCCCC.
   \-----/                     S: CCCCCCC......
      |        Key:
      |          0 = warm;  9 = 90% cold;  C = cold;  . = empty
      |          Leftmost soda/pop will be dispensed next
   ---^---


And, in RFC1288 (The Finger User Information Protocol), the use of vending
machines on the net is supported :

#2.5.5.  Vending machines
#
#   Vending machines SHOULD respond to a {C} request with a list of all
#   items currently available for purchase and possible consumption.
#   Vending machines SHOULD respond to a {U}{C} request with a detailed
#   count or list of the particular product or product slot.  Vending
#   machines should NEVER NEVER EVER eat money.
#



III.4 - I heard there was a POKE command on the {your computer here}
        that would physically damage the hardware.  Is this true?

For those not used to it, a POKE command put some value in some position in
memory.  Thus, POKE 16510,0 changes the number of the first line of a BASIC
program in a Sinclair ZX81 to 0 by overwriting the real number in that
position.

About physical damage: apparently, you could make the monitor of a PET computer
catch fire with a POKE.  The poke controlled the size of the screen for the
electron beam (which was under computer control).  The idea was that you could
change the screen size if you wanted to get around variations on the screen.
Anyway, setting to Zero meant the computer would try to paint the entire
screen in the center of the screen, thus burning out the phosphor on the
monitor.

Also, in some IBM PC hardware you could burn the flyback transformer inside
the monitor with an OUT, reprogramming the MGA video card.

Finally, I heard a story about a virus that actually changed something in
the monitor of the infected computers, and caused them to explode (or burn).
Does somebody know something about it ?



III.5 - What should I do to an old CD ?

Microwave it.  Put in in the microwave oven, above a cup turned upside
down (the cup, not the disk), set the power to HIGH, the timer to 5 seconds,
turn off all the lights, and make sure you watch.  You will never use this
CD again.  The microwave oven is left apparently intact.



III.6 - Is it true that there is a cat printed on the motherboard of
        Sun SPARCStations IPX ?  Why ?

Yes, it is true (don't believe me ? open yours !).  It is supposed to
be the comic strip caracter "Hobbes" (from Calvin and Hobbes).  The Sun
internal name for the IPX is "Hobbes" (the SparcStation 2 is Calvin).



III.7 - Why did IBM choose the 8088 rather than the 68000 as the processor for
        their first PC?

The IBM PC was supposed to be a low-end model machine that would compete
with CP/M machines and the Apple II, but not with IBM's planned larger
"PC's" (which never left the ground). For that reason, it needed a 16-bit
CPU, but not too much memory.

With its 8-bit data bus, the 8088 would lead to cheaper hardware
than a 68000-based machine. The limited address space (1MB, further
reduced by IBM's designers to 640 KB) wasn't perceived as a problem
since nobody could imagine anyone needing so much RAM in a PC
anyway.

Also, the 8088 has the advantage of allowing easy proting of 8080/Z80
code. This meant that lots of software could be produced very quickly
by porting existing CP/M programs (such as Microsoft Basic and the
WordStar word processor).



III.8 -  What does VAX mean? Why did early VAXen have model numbers starting
         with "11",like 11/780, 11/750, and so on?

Rumour has it that the 11/780 was originally intended as the PDP 11/78 with
"Virtual Address eXtension" (i.e. virtual memory), but Digital choose
to present their new 32-bit line of computers under the name "VAX"
rather than "PDP".

The 11/xxx series of VAX machines all had a special "compatibility mode"
in which they can run PDP-11 code.



IV - Origins

IV.1 - What are the origins of Usenet ?

Read the FAQs :-).  Actually, it is posted to news.answers, with
the subject "USENET software: History and Sources".


IV.2 - ... C ?

Quoted from _The_Secret_Guide_To_Computers (a GREAT book, by the way),
(c) 1991 by Russ Walter (15th edition):

   In 1963 at England's Cambridge University and the University of London,
researchers developed a ``practical'' version of ALGOL and called it the
Combined Programming Language (CPL). In 1967 at Cambridge University, Martin
Richards invented a simpler, stripped-down version of CPL and called it Basic
CPL (BCPL). In 1970 at Bell Labs, Ken Thompson developed a version that was
even more stripped-down and simpler; since it included just the most critical
part of BCPL, he called it B.
   Ken had stripped down the language _too_ much. It no longer contained
enough commands to do practical programming. In 1972, his colleague Dennis
Ritchie added a few commands to B, to form a more extensive language. Since
that language came after B, it was called C.
   So C is a souped-up version of B, which is a stripped-down version of BCPL,
which is a stripped-down version of CPL, which is a ``practical'' version of
ALGOL.



IV.3 - ... Unix ?


IV.4 - ... structured programming ?

Not sure, but this must have originated at the end of the '50s,
probably connected with the Algol 58 report.



V - Firsts

V.1 - When/what/where/who/... was the first {something} ?

It is usually a controversal issue.  Many many times the first {something}
wasn't documented, or is poorly documented, and nobody knows anything
about it except from hearsay.  Anyway, here goes a small list:

- Computer:  look at the second file of this FAQ.  It contains a little
history of computers.

- Computer programmer: Lady Ada Lovelace was one of Lord Byron's daughters,
and a friend of Charles Babbage.  She wrote numerous programs for the Analytical
Engine, and so qualifies as the world's first computer programmer.

- Stored program to run: The Manchester Mark-I-Prototype ran the first stored
program in the world (a program to find greatest common factors) on 21st June
1948.

- E-mail message: probably internal messages were around for as long as there
was systems providing it.  It can be probably by 1963 or 1964.

- Computer game:  people have been programming games for as long as there
have been computers. There was research in getting computers to play
Tic-Tac-Toe, chess and checkers going on already in the early 1950's.  Also,
the following quotation sheds some light in the issue:

        "...The Mark I's random number generator ... supplied some fun
        and games.  F.C. Williams ... wrote a little gambling program
        that counted the number of times a given digit, from 0 to 9, was
        produced by a run of the generator.  But Williams adjusted the
        generator to lean toward his favorite number, and he enjoyed
        betting against unsuspecting visitors.  The beginnings of
        computer crime!"

                -Bit by Bit, Stan Augarten p. 212, ISBN 0-89919-302-1

- "Adventure" game: ADVENT, also known as Colossal Cave, by Crowther and Woods
(see the rec.{games,art}.int-fiction FAQ's for more info). There was an
earlier precursor, though: "Hunt the Wumpus", which is not an adventure game
as we know it, but it is the first game with a stored map. See the Jargon File
under "Wumpus".

- Graphics computer game:

- Use of microprogramming:  Maurice Wilkes on the EDSAC.

- Use of virtual memory: Atlas at Manchester University.

- High level language : Fortran, designed at IBM in 195?.



VI - Jokes

I am not sure of what sort of thing could be put here.  We may even do it
in another file, and post it less frequently to the net.  I accept any
suggestion.


VII - Net resources

VII.1 - Who do I call if I have a problem with <something> ?

[The suggestion of this question came from [e-mail] (Peter da Silva)
and I don't have any idea of what to put here.  Should it stay here, I would
need information.  Somebody ?]

VIII - Acknowledgement

Contributions were received from :

bryan o'connor <[e-mail]>
[e-mail] (Daniel Edward Lovinger)
[e-mail] (Scott Forbes)
Malcolm Shute <[e-mail]>
[e-mail] (Nelson Bishop)
Dave ([e-mail])
[e-mail] (Thomas Koenig)
"T.G.A." Rushton <[e-mail]>
Mark Harrison <[e-mail]>
[e-mail] (Danny R. Faught)
[e-mail] (Fernando da Silveira Montenegro)
[e-mail] (Jeremy Elson)
[e-mail] (Mark Brader)
[e-mail] (M. Knell)
[e-mail] (Jeff Weisberg)
Peter Neumann <[e-mail]>



IX - Things I am looking for

IX.1 - The real story of why IBM couldn't reach Gary Kildall in 1981.

IX.2 - Suggestions on what to do to sections VI and VII

IX.3 - Origins of Unix

IX.4 - The old story about viruses in printers (Gulf War, Iraq, etc.)

IX.5 - Interesting stories that fit (anything !)

IX.6 - Should I put the answer to question II.2 (famous persons in the net) as
a 4th separate file ?  If the original mantainer of that list can't keep
doing it (I am trying to contact him; the last information is that he is on
vacations in Brazil), I can take the job.

IX.7 - First graphics computer game

IX.8 - Virus that exploded monitors (see III.4)

Thanks to everybody.
--
Wilson Roberto Afonso  | Instituto de Informatica - UFRGS
[e-mail]    | Porto Alegre  -  RS  -  Brasil
"..If you own a machine, you are in turn owned by it, and spend your time
serving it...."    The Forbidden Tower, Marion Zimmer Bradle