
The Electronic Computers, Part 2: Colossus - Hooke
https://technicshistory.wordpress.com/2017/09/20/the-electronic-computers-part-2-colossus/
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Animats
Good article. It gives Tommy Flowers the credit. He doesn't get mentioned
much.

Colossus wasn't a computer as we think of one today. It was a key-tester, like
a Bitcoin ASIC. No memory, just a few registers. No stored program.

What we think of as a computer today is a general purpose, stored program,
digital machine. Colossus was a special-purpose, hard-wired program digital
machine. There were many such special-purpose machines before full-fledged
computers appeared.

Just before WWII, several groups were working on electronic arithmetic units.
A. Halsey Dickinson at IBM was working on vacuum tube arithmetic, and by 1942,
had an electronic multiplier.[1] Some of those circuits were used in the
ENIAC, and by 1946, IBM had an electronic multiplier as a product, the IBM
603.

IBM's 600 series machines somehow don't seem to be mentioned much in the
history of computing. They were commercial products, so they had to work
reliably and be cost-effective. The IBM 601 (1936) was the first fully
automatic multiplier - electomechanical, punch cards in and out, a few
registers of memory. The 602 and 602A added division. The 603 did the same job
as the 602, but using vacuum tubes. The 604 (1948) was plugboard programmable
with up to 40 program steps. There were more 600 series machines, up to the
IBM 650, on which Knuth learned to program. The 650 had a magnetic drum and
real stored programs.

The big problem in the early days was memory. It was clear by the mid-1930s
that electronic arithmetic was possible, but nobody had a good storage device
yet. The early approaches were recirculating delay lines (slow, sequential
access, not much capacity), magnetic drums (slower, sequential access, more
capacity), and Williams tubes (faster, expensive, not much capacity, but
random access). Core memory was the first technology that really worked well.
IBM developed automatic looms for weaving it, which made it sort of
affordable. Still, through the 1960s, memory was about a million dollars a
megabyte.

There was a whole sideline of special-purpose electronic computing devices in
the 1950s and 1960s, when general-purpose computers were too expensive.
Teleregister did special-purposes machines for stock markets and airline
reservations. American Totalizator did special purpose machines for
racetracks, and was an investor in Univac. There were cute little machines
such as the Mathatron (an early calculator the size of a desk) and Mem-O-Ree
(an inventory control system). These all had electronic computing components
but were not full general purpose computers.

[1]
[http://www-03.ibm.com/ibm/history/ibm100/us/en/icons/ibm603/...](http://www-03.ibm.com/ibm/history/ibm100/us/en/icons/ibm603/breakthroughs/)

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AndrewOMartin
There shouldn't be anyone reading this site who lives within an hour or so of
Milton Keynes that hasn't made pilgrimage to Bletchley Park.

The history of that site is remarkable and accessible, and on the same site is
The National Museum of Computing, which has pretty much one of everything
since the dawn of computing.

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KGIII
I did some work in the UK and was staying in London, not far from the bit they
call the City if London (I think they said it was just like a square mile, or
similar.)

Anyhow, one of the people I was there to work with brought me over to
Bletchley Park and to the museum. It was easy to spend the full day there
between the two.

So, even if you don't live there, I recommend visiting even if you're more
than an hour away. I seem to recall the drive taking about an hour and a half,
though my memory may be fuzzy. I was there in 2007 and I think they'd just
recently opened.

If I'm back in the area, I'll be sure to visit again.

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kar1181
There's a train out of London Euston that will get you there in ~ 30 minutes.

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KGIII
I'll have to try to remember that when I am back in the UK. I was in the other
guy's car and the trip was their idea. They wanted to see the computer museum
as it had just opened recently, at least that is how my memory indicates the
order of events.

Either way, it's well worth visiting. Given that it had just opened, and now
been more than a decade, I suspect they have all sorts of additional displays
these days. So, when I'm next in the general area, I will make it a point to
visit again.

Tangentially related: I also highly recommend the Natural History Museum. I
really enjoyed that. Though, I'd recommend setting aside a couple of days for
that one.

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chr15p
The Natural History is great, but can be horribly full during school holidays.
But if you cant get in just around the corner is the Science Museum which is
also excellent.

Especially relevant for this audience is its Information Age gallery which
covers "6 networks that changed the world", telegraph, broadcast radio and tv,
telephony, satellite (including GPS), the web, and cell phone networks.

Best of all both museums are free to get in (donations welcome).

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KGIII
Oh, yes! I should have mentioned how much I enjoyed the Science Museum. I
don't usually do a lot of touristy things, but I do love going to museums. The
Science Museum was excellent.

I also enjoyed the Brittish Museum, London Museum of Steam and Water (I think
that was the name), the Museum of London, and Clink Prison Museum, though that
was kind of small.

I also did a police museum but I can't remember the name of it.

London has some great museums and a fairly long history, so I highly recommend
anybody visiting make it a point to visit at least a few of them. They were
also inexpensive to visit, as I recall. I think some of them only required a
donation? I am not entirely sure, it has been quite a while since I have been
back. I've only had one post-retirement visit.

Hmm... I should go back. Maybe I'll go over the winter.

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roywiggins
The Museum of the History of Science in Oxford is also very, very good if you
like scientific artifacts. Not quite as overwhelming as the Science Museum,
and the building itself has history- the basement was probably an alchemical
laboratory however many years ago.

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KGIII
Duly noted, thanks. That is one that I haven't been to.

I was just talking with the missus and she's never been to the UK so we are
tentatively looking to go over the coming winter, probably after the new year.

I will put that one on my list of 'must do stuff.' I've seen the museum pop up
in documentaries and have just taken a peek online. It looks like it will be a
good time.

Seriously, thanks. I love the UK and museums. Being reminded of another one is
a good thing. I'd forgotten all about that one.

It's too bad that I can't time it to do one of the Royal Institution Christmas
Lectures. I have wanted to do one of those, in person, for a very long time.
Fortunately, I'll be able to watch them.

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wiz21c
This reminds me of this movie : Colossus The Forbin Project Ending. A really
good movie about AI.

(warning, spoiler)

[https://www.youtube.com/watch?v=iRq7Muf6CKg](https://www.youtube.com/watch?v=iRq7Muf6CKg)

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loudouncodes
That is one of my favorite movies. And while the computer in the movie is
named Colossus, it has nothing to do with this story. In fact, the real
Colossus was still classified at the time this movie was made; use of the name
is sheer coincidence.

If you liked the movie 'Trancendance' from a few years ago, check this out...
you'll see some awesome parallel storytelling.

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sleavey
"The leader of a team that rebuilt Colossus in the 1990s showed that, in its
wheelhouse, [Colossus Mark II] would still easily outperform a 1995-era
Pentium processor."

I find that utterly incredible. What a feat of engineering for the 1940s.

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1_2__4
THERE IS ANOTHER SYSTEM

