Two decades ago, a team of employees at IBM Corp., nicknamed the ''Dirty Dozen,'' launched a raid on their own company's business practices, which the raiders saw as stodgy.
The commandos won, and their victory came close to destroying IBM. But the Dirty Dozen also gave the world the IBM 5150, one of the most significant technological developments of the 20th century.

Better known as the IBM Personal Computer, or simply the PC, it was the first in a line of machines that have sold by the hundreds of millions.
The 5150 and its descendants have transformed modern life. They're electronic test tubes for scientists, paintbrushes for artists, playthings for children. They run factories, supermarkets, and banks.
An industry researcher, Roger Kay of IDC Corp. in Framingham, said of the PC: ''It's changed everyone's life. I think it might be comparable to the automobile and the telephone.''
But like the automobile and telephone industries, the PC business has lost its youthful luster. According to IDC's figures, sales of PCs fell this year for the first time since they were introduced in August 1981, in part because of the economic slump, but also because nearly 60 percent of US homes and most businesses already have computers.
The excellent quality of new PCs has only compounded the problem: Early computers had to be replaced every couple of years to meet the demands of improved software; today's PCs will run just about any software on the market, meaning there is little incentive to upgrade.
Like cereal and laundry powder, the PC finds itself in a mature market.
''The PC itself is as important as always,'' said a Yale University computer scientist, David Gelernter. ''The industry is confused about how to use it.''
The PC has transcended its original use as a stand-alone number-cruncher for running business applications, storing small databases, and playing games.
Now, millions of PCs are gateways to corporate networks and the global Internet. Much of the information that people want is stored on the network, not on PCs. It's the network that matters, not the beige box plugged into it.
''Personal computing is no longer a personal computer,'' said an MIT computer scientist, John Ankcorn. ''It is computing that is personalized to the user.'' Whether the computer is on the user's dining room table or in a coin-operated Internet booth at the airport is immaterial.
The sheer power of modern electronics is transforming the size and shape of computing devices, and the result is that the traditional PC is morphing into other devices - wireless telephones and palmtops, among others.
Microsoft Corp. is banking on a new generation of portable computers without keyboards that will understand speech and handwriting. And large amounts of computing power are being built into many other common devices, including cars. All these gadgets are furthering the computerization of the planet, a process that began well before IBM got into the PC business.
Lost in the hoopla over the IBM PC is the fact that it was not the first personal computer. Forerunners appeared as early as 1971, and personal computing as a viable business began with the MITS Altair 8800, a build-it-yourself computer kit that went on sale in 1975.
It was a magazine article about the Altair that inspired Bill Gates to drop out of Harvard and go into the software business.
By 1977, anybody could walk into a retail store and buy a primitive PC. The Apple II, the Tandy Radio Shack TRS-80 and the Commodore Pet sold hundreds of thousands of units, long before IBM's PC came along.
So why remember the PC's birthday? For one thing, it's still alive. Apple IIs, Pets and ''Trash-80s'' are found only in museums and attics. But the vast majority of computers are still based on the PC standard.
The latest Pentium 4 desktop computer is just a vastly improved version of the original 1981 model.
More importantly, the PC was the machine that transformed desktop computing from a business tool or an elite hobby into a commonplace of modern life. Just as Henry Ford's Model T was the first automobile for ordinary people, so the IBM PC became the computer for the common man.
That was a suprise. The revolution was supposed to have been led by the long-haired upstarts at Apple Computer, not the stodgy corporate superpower that was IBM. This was a company that specialized in mainframes and minicomputers. It studied the PC market for three years before it dived in. In the process, its researchers learned a crucial lesson: hurry up.
''For IBM's history, if you were on a project, you usually took it from start to finish, and it usually took years,'' said an IBM engineer, Rob Baker, a veteran of the Dirty Dozen. ''In our case, we had one year to put out the project from start to finish. ... I guess somebody figured out that that was the longest you could take to put out a consumer product.''
The Dirty Dozen had no time to design custom chips and software from the ground up. Instead, IBM bought its processor chip from Intel Corp., and its operating system software, the core program that makes everything else work, from Gates at Microsoft. Both Intel and Microsoft were free to sell these products to anybody else.
At first, nobody at IBM cared, because the firm's top executives saw the PC as a minor sideline. ''We started out with an initial market assessment of 50,000 units over five years,'' Baker said. ''The people who were longtime IBMers dropped their jaws and said, `How can we ever sell that many machines?'''
IBM sold 35,000 machines in the first five months, and demand kept growing. Business was so good that firms like a Houston upstart, Compaq Computer Corp., bought Intel chips and Microsoft software, then built machines that were perfectly compatible with the original IBM PC. Soon there were ''clone'' PC makers popping up all over the world, and driving down PC prices. Meanwhile, customers bought fewer of IBM's high-profit mainframes, and moved the work onto cheap PCs instead. By the early 1990s, IBM was losing billions, and it has never regained its predominance in the computer industry.
But the system designed by the Dirty Dozen is still the dominant platform for desktop computing, although it is receding in importance with data networks taking center stage.
''I've often said it shouldn't be called a personal computer; ... the computational aspects of it are fairly unimportant,'' said Mike Winkler, senior vice president at Compaq. ''What it's become is largely a communications device and an information access device.''
Winkler foresees the home computer becoming the mediator that delivers and stores all manner of digital information, and that distributes it throughout the house. Already, people use their PCs to listen to Internet radio broadcasts and to download music; someday they may just as easily download TV programs, store them, and watch them anytime.
The TiVo home video recorder already works on this principle; the same software could be built into a high-powered central computer, a household server that would distribute music, video, and Internet data to every room in the house.
Such a master control system would make use of the wasted horsepower of today's muscular computers. A lot of that power will go toward making future PCs easier to use.
''The best mechanism for communications... is two-way spoken dialogue,'' said Michael Dertouzos, director of MIT's Laboratory for Computer Science. Today's speech recognition software is good for little more than dictating memos. Dertouzos says his colleagues are at work on software that will allow PC users to converse with the machine, which will respond in a natural-sounding human voice.
MIT's Ankcorn goes further. He's working on a computer system that can watch the user and his environment and tailor its actions accordingly, just as a human being can do. For instance, says Ankcorn, a computer could blank out a screen when someone looked over a user's shoulder, or stop saying ''You've got mail'' when a user is on the telephone.
''It's not about the ability to give commands,'' Ankcorn said. ''It's the ability for the computer to just know what's the right thing to do.''
Ankcorn's efforts are part of a project aimed at making the personal computer far more powerful than ever - by making individual computers nearly irrelevant. Project Oxygen is an effort to integrate computers and the Internet so completely that any computing device with network access is interchangeable with any other.
Information would still be stored on a home or office machine, but that data would be ''mirrored'' to remote servers and made available to a user on any networked device.
In an Oxygen world, losing a laptop full of business data would be no more than a costly nuisance.
Even so, networks break down or get overwhelmed by attacking vandals. And many people will always insist on the privacy and security of data stored on their own machines. Chances are, that machine will be some form of the old 20-year-old IBM PC.
''You can't keep the hardware down,'' said Yale's Gelernter. ''The hardware is too powerful; it's too cheap. It just keeps coming back, like dandelions on your lawn.''