BOSTON -- One of the true pioneers of the computer age never lived to see the light bulb, let alone a silicon chip.

Englishman Charles Babbage is credited with creating the first outline of what eventually became the modern computer. But hindered by 19th-century technology, his dream wasn't realized until some 70 years after his death.

Babbage is one of 34 computer industry founders profiled in the recently published "Portraits in Silicon" (The MIT Press, Cambridge, Mass., $24.95), a book by Time magazine reporter Robert Slater.

Slater discusses the obvious candidates for the computer hall of fame: Apple Computer cofounder Steven Jobs; Electronic Data Systems' H. Ross Perot. But he also sheds light on many of the lesser-knowns, such as Babbage.

The self-taught mathematician, who died in 1871, received recognition for his work only after the dawn of the computer age in the 1940s, according to Slater.

"Were he to visit our era, he would be startled to find computers so widely used," Slater writes.

"And yet, should he see the inside of any standard computer his shock would diminish. Though he might be taken aback by the use of electronic technology, the basic concepts of the central processing unit and memory would be strikingly familiar."

Babbage's "Analytical Engine" would have been programmed by punch cards, similar to the ones used by modern computers until the 1970s. His device, powered by a steam engine, would have contained a crude form of memory, and was designed to perform one arithmetical operation a second. However, he never managed to get the giant contraption constructed.

The modern computer age was launched by English mathematician Alan Turing, whose device, which also was never built, was described in a famous 1936 paper. The Turing Machine was designed to scan a paper tape for instructions and would have solved mathematical problems.

Turing later oversaw the construction of what is considered to be the first operational electronic digital computer, Slater said. Hired by the British government during World War II, Turing helped develop a series of computers to crack German codes.

"Decidedly limited, these special-purpose machines had the sole function of cracking ciphers," Slater writes. "Still, they were the first major computers to employ vacuum tubes -- 2,400 in each machine -- as digital on-off switches."

Turing's machines predated by two years the ENIAC, the room-size computer built at the University of Pennsylvania and often credited as the first electronic computer.

Slater said he became interested in computers after he began using one to write. While researching a possible book about the field he discovered a void.

"There were very few books that focused on the people behind the computers. Some had been mentioned here and there. But nobody had done a series of profiles," he recalled in an interview.

"I felt there was a very unique opportunity. This was a field in which you could still, in 1985 -- which is when I did it -- you could go out and talk to the pioneers. You can't go out and talk to Wilbur Wright."