BBC correspondent John Moylan reports on Baby's children

Baby, the world's first modern computer is celebrating its 50th birthday and to mark the occasion it is set to retrace its first steps.

Today there are computers which are 25 million times faster, but the start of the information age can be traced back to Baby's birth.

Baby took 25 minutes on some calculations

Built in 1948 at the University of Manchester, Baby was the first computer to be capable of storing a program in its own memory.

It was capable of only a few calculations and often did not work, but it was to become a model for the first commercially available computers built in the 1950s.

Brought back to life

To celebrate the anniversary Baby, which is kept at the Manchester Museum of Science and Industry, is being brought back to life.

Valves not chips were the order of the day in 1948

It will be turned back on Wednesday by Tom Kilburn, one of the engineers who first threw the switch in June 1948.

Mr Kilburn, 76 will be joined by Lady Williams, the widow of his late colleague Freddie Williams.

The original program that ran on Baby will be re-run on Sunday morning exactly 50 years after it was first used.

'It's exceeded our wildest dreams'

When Baby was born few people appreciated the impact that computers would have on modern life.

Tom Kilburn: "We knew it was important."

In 1945 the President of IBM predicted there would only ever need to be about five computers in the world.

Although today some people fear that we have become too reliant on computers, Mr Kilburn is proud of his creation's legacy.

Baby's control panel

"It's exceeded our wildest dreams," he said.

"I am quite sure there will be some misuse of computers as there is with any tool, but that doesn't mean that we have to pack in the whole business of trying to improve the quality of life."

Baby's rebirth is part of Digital Summer 98, a festival being held to celebrate Manchester's role in the early development of modern computing.