Processors investigate

Cray-1 supercomputer: How I discovered a dinosaur at the museum

A chance visit to a London museum uncovers a mythical beast from computing's past.

The other day I was in Exhibition Road in London, on my way back to the underground after a meeting. The Science Museum is next door and having not visited since my children were small, I decided I'd have a quick look around.

With the back panels removed, the Cray-1 reveals an unexpectedly vast quantity of wire. Photo: renaissancechambara/Flickr

I wandered in, thanking myself as a taxpayer for supporting the museum's free entrance policy and set off through the ground floor past the old steam engines, which will be familiar to many generations from school visits.

Past the space display and at the rear of the first floor was a section called Making the Modern World, comprising 150 of what have been judged the most significant items dating from 1750 to 2000 in the Science Museum's collections.

In the middle of this relatively interesting mishmash of items - which range from a V2 rocket to a Model T Ford - was a Cray-1 Supercomputer from 1976, decorated with bright red, blue and green panels.

Now it may be that I am of a certain age, but I was stunned to see this object, which I had regarded as almost a thing of legend. When I started my working life and began to learn about technology properly, the Cray was the fastest computer in the world.

It was familiar only from photos and notable for its sci-fi appearance. A tower of technology, available in various colour schemes, arranged in a C-shape, with an upholstered bench seat around the base that contained power supplies and refrigeration. Beyond that, I knew little more.

Face to face with a real Cray-1, I learned two things immediately. One: from looking at the museum exhibit where inside the C the backs are off the computer, there was a vast quantity of wire inside the Cray, which I was not really expecting.

Two: the museum's explanatory blurb said Seymour Cray, the eponymous designer, favoured simplicity in design right down to his preferred tools of pencils and squared paper.

When I got home I looked up a few things. When the Cray-1 launched in 1976, the first model sold for $8.8m. So yes, they were expensive. That's an equivalent of $35.5m in today's money. Cray sold more than 80 examples of that model, which made the company a success at that time.

Cray said: "Anyone can build a fast CPU. The trick is to build a fast system." He was a keen believer in keeping all data paths of equal length, so that data that was meant to arrive at the same time actually did so. None of the interconnects was longer than four feet.

So as well as being his initial, the C-shape of the computers processor cabinets came from keeping all the interconnects at the back of the circuit boards as close together as possible to keep the length of the wire down.

There it was in front of me - a real machine, but now 35 years old and no longer the fastest computer in the world. It felt in a way like looking at the dinosaur skeletons in the Natural History Museum next door - an echo of the past, no longer living.

I've always favoured simplicity and it's pleasing to learn that Seymour Cray did the same. Gordon Bell, the man who developed the DEC VAX - youngsters, look it up - said, "Seymour built simple machines. He knew that if each step was simple, it would be fast."

If you're in London, pop in to the Science Museum for a look at the Cray-1. Also in the building are other historical computing artefacts including the modern-built Babbage's Difference engine and Ernie, the Premium Bond random-number generator.

It's an eclectic collection - and probably more fascinating to us older IT pros than to the children.

So when was the last time you came across a piece of technology that set you musing about your earlier IT career? Why not share your reminiscences?

About

Nic Bellenberg is an interim CIO and former IT director at publishing house Hachette Filipacchi UK.

7 comments
Rodo1
Rodo1

"If youre in London, pop in to the Science Museum for a look at the Cray-1" Actually, I don't have to go more than a couple of miles. I'm in Boulder, CO, and the National Center for Atmospheric Research has their CRAY - 1 on display in the Mesa Lab. I worked there from 1982 to 1987 for Ampex Corp. maintaining a Terabit Memory System that provided the mass storage requirement of NCAR at the time. The CRAY - 1 was still in service as well as a CDC - 7600 which was also designed by Seymour Cray before he went off on his own. Thanks for the article!

Radar1751
Radar1751

Back then I was programming HP 2100s and DEC PDP-8s. I also did a lot of backplane wire wrapping on prototypes. Having been from Wisconsin, I followed the development of the CRAYs with a little more interest than the average geek, because the east and west coasts always depicted people from Wisconsin as hicks. It was a great source of pride that the fastest computers in the world, for some time, came from a little town in Wisconsin. Thanks for the blast from the past.

jcs.znet
jcs.znet

I went into the Jodrell Bank museum in the 1980s and recognised a computer that was on display. I designed it in 1963 and I personally commissioned that one. I wonder what has happened to it since the museum closed? Are there any more around? I have seen the one at Bletchley Park but I am certain it was never a working model.

theopaone
theopaone

I taught a class at Cray in Chippewa Falls, WI in the mid 80's. It is a small town in northern Wisconsin, also home of Leinenkugel's brewery. I was given a tour of the factory floor and was amazed to see the computers were created using wire wrapping rather than printed circuit boards. These computers were hand built, mostly by women. It was amazing to see the innards of the these machines and the people assembling them. The nickel Leinie's at the nearby bar were also a treat.

Rick in PA
Rick in PA

Thanks for the descriptive narrative on the Cray. I'm not an IT guy. I was interested in computers as a young man. I had a buddy that I ended-up steering into computer programming, and he in turn steered me into mechanical engineering. It worked-out for both of us. It's nice to see the old stuff appreciated. I always liked elegantly simple design myself...

steveshepherd
steveshepherd

It must be that time of year! I was thinking about the first computer that I worked on back in the late 60's early 70's a LEO III - Boy did that make me feel old - even the photo's were in black and white! It still managed to run the payroll, rents and rates and vaccination and immunisation systems for 4 London Boroughs though. 5bit baudot paper tape! Steve Shepherd

BALTHOR
BALTHOR

"After the Van de Graaf generator started up we knew that we had velocity of light electrons".