Close, Sometimes Dry, Detail of Magic of 1st Internet ‘Wizards’ ’ : WHERE WIZARDS STAY UP LATE: THE ORIGINS OF THE INTERNET, By Katie Hafner and Matthew Lyon(Simon & Schuster; 304 pp., $24)

In the summer of 1969, the world watched in awe as America put the first man on the moon. It was the Space Age, after all, and just a few short years after mobilizing to meet the challenge of Sputnik, Neil Armstrong was up there on the lunar surface.

Hardly anyone back then had any idea that another group of gearheads, up in Cambridge, Mass., was doing something at the very same time that would come to seem even more important. They were inventing what we now know as the Internet.

Space exploration will resume in earnest sooner or later, but meanwhile we seem to be firmly stuck in the Information Age. The moon might as well be cheese these days, but the Internet--now there’s a happening place.

Just how the Internet did in fact happen is the subject of “Where Wizards Stay Up Late,” an important new book by Katie Hafner and Matthew Lyon that focuses narrowly on, as its subtitle puts it, “The Origins of the Internet.”

I’m sure there will be endless Internet debate over the extent to which the authors misallocated credit, misunderstood technology, missed shadings, nuances and so forth, but as far as I can tell their research is meticulous and their presentation admirably straightforward.

On the other hand, the book is somewhat frustrating for its limitations. The focus is heavily on Bolt Beranek & Newman, the extraordinary Cambridge consulting firm that carried out the original federal contract for the creation of what became known as ARPANet.

In fact, the authors disclose--in acknowledgments placed at the back of the book--that their volume “grew out of an idea that originated” with BBN, which wanted its role in founding the Internet to be recorded, and that BBN threw open its archives and even “helped fund the project as well, while agreeing to exercise no control over the content of the book.”

The result is a somewhat BBN-centric work that nevertheless provides an in-depth account of how the Internet was born. As it turns out, the toddler had many parents, all of them, it seems, frighteningly smart. There was, for instance, the psychologist J.C.R. Licklider, whose seminal paper “Man-Computer Symbiosis” in 1960 looked ahead to an era when people and computers would interact on a basis no one before had imagined.

More directly, the network we know today has its roots in an initiative undertaken by a single visionary at the Defense Department’s Advanced Research Projects Agency in 1966. The official, Bob Taylor, needed just 20 minutes to persuade his boss to pay for a project to try to connect some of the large, disparate computers used by the far-flung researchers Taylor’s wing of ARPA was funding.

Contrary to popular belief, the Internet wasn’t designed as it was just to be bomb-proof, although that seems to have been a side effect. Rather, such a network would permit more efficient use of computers, which were expensive in those days, and would facilitate sharing of resources at different locations, avoiding duplication. Hardly anyone thought much about e-mail, which later became the Internet’s killer application.

To make the new network happen, Taylor recruited a young MIT graduate named Larry Roberts, who could read so fast he was constrained only by how fast he could turn the pages of a book. Stopped by a traffic cop for speeding after merging onto a highway, the authors report that Roberts “went back to the scene and carefully measured off the distances. He gathered data on the engine output and weight of his VW bug, factored in Newton’s law of inertia and made a few other calculations, and was prepared to go before a judge” to prove he couldn’t have accelerated to the alleged speed in the given distance, until finally his friends talked him out of it.

If Roberts was the network’s principal architect, the brilliant young men at Bolt Beranek & Newman were the ones who actually built the thing. BBN in those days was sometimes called “the third university” around Cambridge because it was a refuge for so many thinkers that it seemed to rival nearby MIT and Harvard. Frank Heart, a BBN executive, supervised a team that conceived a network much faster than the one Roberts demanded, and despite some remarkable obstacles, created it on time. Almost as soon as the first two computers (at UCLA and SRI, a research center in Palo Alto) were hooked up, in autumn of 1969, the network worked.

Not everybody in this book was always so smart, of course. Among the classic bonehead decisions described here: AT&T; turning down a chance to own the whole incipient network, for instance, or BBN deciding not to get into the business of making routers (which enable local networks to connect to the Internet), a business now worth billions a year.

In detailing all this, Hafner and Lyon have written something of a bureaucratic history, and I must confess, as someone who is fascinated by the Internet, that I found it surprisingly dull in places. The writing lacks personality and sometimes I couldn’t follow the explanation of technical matters.

The authors’ focus is so extreme, moreover, that short shrift is given to such later developments as Usenet and the World Wide Web. Nor is much attention given to what the Internet may become--or what its inventors think or hope it may become.

Then again, this really is a book about the origins of the Internet, and on that account it performs well. The authors do an admirable job of showing how the characteristic Internet culture developed, and even the most hardened geeks may grow misty-eyed to read about how Telnet came into being, who chose the @ sign for e-mail addresses and where the domain name system comes from.

You can’t get “Where Wizards Stay Up Late” by e-mail or ftp, but anyone professionally or passionately involved with the Internet will want to read it anyway.

For More on the Internet

Preston Gralla’s “How the Internet Works” is a large-format, easy-to-follow guide to what the Internet looks like, depicting the Net graphically with colorful diagrams and straightforward text. This isn’t a how-to book. Instead, it helps you understand just what happens when, for instance, you write some e-mail and click “Send.” “How the Internet Works” ($25) is published by Ziff-Davis Press. Be sure you get the version that says “all new edition.”