‘The Baby’ Computer Gets a Rebuild for 50th Birthday

“The Baby,” the world’s first programmable computer, was a cumbersome giant that occupied the space of a large room.

When its three inventors brought it to life at Manchester University in the north of England in 1948, they paved the way for the modern personal computer.

Baby, a tangle of wiring and crude electronic tubes, was gradually dismantled and forgotten as the silicon chip was developed, which enabled smaller, faster machines to be built. Now, determined to secure Baby a place in history, a team of computer enthusiasts has ventured back to the roots of computer science to reconstruct Baby in time for its 50th birthday next June.

“We’re plowing along and we’re well on schedule for the birthday party next year,” project leader Chris Burton said.

Large-scale celebrations are planned for June 21, 1998, marking the day the first program ran on the world’s first fully programmable electronic digital computer.

“Baby was a triumph of British innovation,” said Burton, a retired computer engineer. “Today’s computers are smaller, faster and much more powerful than Baby, but they work on exactly the same principle.”

Burton has had to rely on a 50-year-old notebook of scribbled circuit diagrams and a pile of yellowed photographs to piece together the replica. He spent months hunting down old electronic tubes in collectors’ attics across Britain and even tracked down the original metal racks, which had ended up propping up a flower bed in somebody’s garden.

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Baby’s memory was only 1,024 bits, much weaker than modern computers, which boast around 164 million bits.

“With a memory of that size, you couldn’t run any of today’s programs, except maybe a very basic version of a game like chess,” said Colin Wilson, applications development manager at software company Erdas UK.

Nevertheless, Baby had seven types of instruction loop, meaning that with a bigger memory it would have been capable of running the most sophisticated programs. Earlier computers like Colossus, the street-sized British code-cracking machine built around 1943, and ENIAC, the U.S. Army’s number-crunching computer in 1946, did not have Baby’s stored program facility. Both had to be reprogrammed manually before a new program could be executed.

Baby was not originally intended to rival these but was built by Tom Kilburn and Geoff Tootill to test out a stored memory being designed by the late British professor Freddie Williams.

“The interest was to build a digital memory that you could read and write electronically,” said Dai Edwards, who helped out with the project as a 20-year-old student. “Having designed the memory, we needed to test it. The idea was to build a machine in which you could input not just numbers but codes which could be interpreted as instructions.”

The memory used cathode ray tubes to store data as charged points on a screen. An electron beam scanned the points, allocated binary ones or zeros and could read the information back on demand. Tucked between huge racks of circuit wiring were a vertical keyboard for inputting instructions and a screen displaying the results as green dots.

As the inventors realized the importance of their creation, the pace intensified to run the first program.

“It was a moment to remember” is how Kilburn described producing the first set of results. Early trials produced a “random dance” of light points on the screen, but on June 21, 1948, something different happened.

“There, shining brightly in the expected place, was the expected answer,” he said. “Nothing was ever the same again.”

News of Baby’s premiere quickly hit the headlines. It was hailed as “a marvel of our time--the memory machine which can solve the most complex mathematical problems.”

Its inventors were bombarded with letters from DNA crystallographers, weather forecasters and atomic energy researchers who had mathematical calculations that were too lengthy to solve by hand. “They had problems to solve and we were interested in making computers. It was a meeting of two sets of enthusiasts,” Edwards said.

Ferranti Ltd. developed the Mark 1 computer on Baby’s design and sold it commercially. By 1951, the original machine had been taken apart as the university team moved on to further achievements.