

61-year-old computer springs back to life - brequinn
http://edition.cnn.com/2012/11/21/tech/innovation/witch-computer-restoration/index.html?hpt=hp_t3

======
Peroni
"Springs back to life"... talk about sensationalism.

It 'sprung' back to life after a three year restoration project.

The original article is a much more appropriate read:
[http://www.tnmoc.org/news/news-releases/worlds-oldest-
origin...](http://www.tnmoc.org/news/news-releases/worlds-oldest-original-
working-digital-computer)

The tech spec is brilliant:

    
    
        Power Consumption: 1.5kW
        Size 2m high x 6m wide x 1m deep
        Weight: 2.5 tonnes
        Number of Dekatron counter tubes: 828
        Number of other valves: 131
        Number of relays: 480
        Number of contacts or relay switches: 7073
        Number of high speed relays: 26
        Number of lamps: 199
        Number of switches: 18

~~~
DanBC
>"Springs back to life"... talk about sensationalism.

[...]

>The original article is a much more appropriate read

From your the first line (in bold) of your link:

> _The world's oldest original digital computer springs back into action at
> TNMOC_

~~~
Peroni
The original shares the same ridiculous title but the article itself is a much
better read.

~~~
inopinatus
It's only ridiculous if you are a literal-minded pedant without a shred of
poetry in your soul.

~~~
lostnet
Is the poetry of talking of systems that spring back to life without a focus
on the 3 years of human effort all that different from the poetry of cat walk
models, photoshop body images, etc?

Poetry can be great, but not when it enforces unrealistic expectations. In
technology we are not above the limerick.

------
shawn-butler
I found it interesting that they compare the ouput to a man with a pocket
calculator when the people these devices replaced were overwhelmingly female.
I can remember reading respected mathematicians approximating the problem-
solving power of early computing machines in “girl-years” and describing
machine labor in “kilo-girl” units.

------
jgrahamc
The BBC has a video of it in operation. Wonderful to hear the sounds of this
machine: <http://www.bbc.co.uk/news/technology-20395212>

~~~
mhurron
The sound is great. Its a shame when you walk into a server room now you don't
hear anything except the AC running. It just doesn't have the same feel.

------
brudgers
_"At a time when iPhones are swapped out every 12 months, the TI-83 calculator
and this computer are among the only pieces of technological machinery that
have survived for decades."_

The TI-83 with a graphic display is recent by comparison to the venerable
HP12C.

[http://www.amazon.com/s?ie=UTF8&keywords=hp12c&page=...](http://www.amazon.com/s?ie=UTF8&keywords=hp12c&page=1&rh=i%3Aaps%2Ck%3Ahp12c)

------
Luyt
I found some manuals on how to program this computer:

Programming manual:

<http://www.computerconservationsociety.org/Wolv-Manual.pdf>

Example programs:

<http://www.computerconservationsociety.org/witch4.htm>
<http://www.computerconservationsociety.org/witch14.htm>

Source: <http://www.computerconservationsociety.org/witch.htm>

~~~
Luyt
It had a built-in watchdog with automatic restart of the program: _"The normal
alarm gives a warning if the computer is inactive for 30-60 seconds. The
delayed alarm returns the computer to the beginning of the programme when a
period of inactivity is detected if the inactivity is not due to either Signal
order._ "

Rudimentary 'stack trace': _"When the computer stops owing to a programme
error on a faulty tape it is useful to know what order is stored in the
control section of the computer or the address from which an order is being
read. Five keys on the Control racks switch in a lamp display showing this
information."_

Programs were written, debugged and staged on paper tape, then went into
production: " _The normal procedure is to make a paper original using the
keyboard perforator. From this a printed slip is produced and checked against
the manuscript programme. Any errors are marked up and if necessary a
corrected paper copy is made. The paper original or copy may then be proved in
the computer and any further corrections inserted. Where the final loops of
tape are required to pass through the computer more than a few dozen times
linen copies are made from the paper originals._ "

Typing errors on the tape were corrected by backspacing over the error, then
punching all holes open. I guess the reading unit recognized this as a NOP or
NULL character.

Deployment of programs were done by glueing both ends of the tape together, so
it formed a loop: " _Splice the tape into loops by cutting the ends to a blunt
point, allowing an overlap of two or three rows. Coat both ends sparingly with
thick paste on one side and join, with the leading end on top. The joint
should be lined up carefully to ensure that there is no discontinuity at the
edges and that the feed holes are clear. Press the joint together firmly and
dry thoroughly before use. Avoid excess paste on the linen tape as the starch
impregnation is easily removed by moisture._ "

------
hayksaakian
Its crazy that calculators have essentially been immune to the turbulence of
the mobile industry of the past several years.

~~~
Jach
The chief reason (at least in the US) is probably due to standardized testing
having a white-list of allowed calculators. Your phone can emulate the TI-89
just fine (and run other tools like LAPACK, PARI, Octave, etc.) but good luck
getting it approved for a test.

~~~
hayksaakian
Just goes to show that the US government is not the only organization capable
of crippling progress.

------
perssontm
Anyone know how this really could be useful? If it took the thing 5-10 seconds
to multiply two numbers, and it also needed input as of punch cards. How could
it at any point be faster than doing calculations manually? I'm genuinely
interested in how it was really used, any hints?

~~~
anonymouz
The BBC article claims that its advantages over humans were that it didn't
make mistakes and would happily churn on for quite a while, with a running
time of up to about 80 hours per week.

I don't know how large the numbers were that needed 10 seconds to multiply,
but even if it is not much faster (or even if it is slower) than a human for a
single operation, a human won't be able to reliably do arithmetic over any
comparable time frame.

~~~
im3w1l
How often would you need to feed it new cards?

~~~
anvandare
It didn't use cards, but paper tape (as seen in the BBC clip). So I guess, in
theory, it could have gone on forever if you just glued a fresh tape to the
end of the old one.

>"It was, of course, slow, not much faster than hand calculation on single
operations, but fully automatic, extremely reliable and utterly relentless. It
took little power and could be left unattended for long periods; I think the
record was over one Christmas-New Year holiday when it was all by itself, with
miles of input data on punched tape to keep it happy, for at least ten days
and was still ticking away when we came back."

[http://www.chilton-
computing.org.uk/acl/literature/reports/p...](http://www.chilton-
computing.org.uk/acl/literature/reports/p009.htm)

------
gldnspud
I went looking for more footage of this computer, sans commentary and heavy
editing, and found this gem: <http://youtube.com/watch?v=OmNRl9hydmw>

