Twenty years ago next week, IBM unveiled the "IBM Personal Computer." The news was startling: Big Blue, the leading manufacture of pricey mainframes for large corporations, was entering a market generally regarded as a hobbyists' niche. And it would be selling these machines retail, straight from stores to small business users and home computing enthusiasts. The 1981 IBM PC, which began shipping two months after the company announced the machine on August 12, was built around a 4.77MHz Intel 8088 processor and other off-the-shelf parts. It had 16KB of RAM - expandable to 256KB - and no hard drive. It wasn't the first "micro" computer. Other manufacturers, including Apple, already had PC-like machines on the market. But IBM's PC was the first created by an established, blue-chip firm, and it was the first to use easily obtainable parts from third-party manufacturers - the architecture that quickly launched a thousand clones. IBM's sales team forecast demand for precisely 241,683 PCs within five years. That figure was surpassed within a month of the PC's debut, IBM said. By the time the five-year mark rolled around, IBM had shipped millions of PCs. "No one knew it was going to be big," recalls Dave Bradley, an original member of IBM's PC development team. He is still with IBM, currently working in the company's eServer xSeries architecture and design department in Research Triangle Park, North Carolina. "At least around here, it's not like those stories you read where [Apple co-founder] Steve Jobs has said, 'We're going to change the world.' " In September 1980, IBM assembled a group of 12 engineers who had previously worked on the company's System/23 Datamaster machine. Datamaster also used an Intel processor, and Bradley speculates that it was the engineers' familiarity with Intel processor architecture that made them attractive candidates for designing the PC. The group didn't stay small for long. Within a month, several dozen IBM workers were attached to the project; by April 1981, the number had ballooned to more than 150. The development cycle was brutally short: IBM wanted the PC ready to go within a year. The developers had tremendous leeway in designing the PC. An IBM task force had met in August 1980 and determined the machine's basic architecture - including the fateful decision to license Microsoft's MS-DOS (Disk Operating System) as the machine's operating system. "The task force had mapped out the boundaries of the continent. We knew where the coastline was. Everything else was terra incognita," Bradley said. Development moved quickly, and at the end of Thanksgiving weekend Bradley and two other engineers made the trip out to Bellevue, Washington, to deliver the first PC to Microsoft - then a fledgling startup inhabiting the eighth floor of a bank building. Bradley remembers reconstructing the disassembled PC - comprising nine boxes of components - in a shipping room turned secret lab. "We were in a room that we shared with shipping pellets - those little Styrofoam peanut things," he said. "When we set the PC up, the thing worked just fine. We didn't have to do even minor surgery. We were somewhat surprised at that." Bradley hopped back and forth between Bellevue and Boca Raton, Florida, the PC team's home base, many times over the next few months. On one of those airplane trips, he and several other developers hashed through what he cites as "one of my favourite examples of the stuff we got to define," the PC's character set. They chose the ASCII (American Standard Code for Information Interchange) set, then filled in the rest of their 256 available characters with characters they'd defined for the Datamaster and others they felt would be useful. The character set they defined has lingered through two decades of successive PC design. Bradley's main claim to fame is developing a key sequence popularized by crash-prone software: the control-alt-delete warm reboot. "Control-alt-delete" was never intended for public use, he said - it was created merely as an aid to programmers on the team. He choose the three keys, he said, because he wanted to pick keys spaced apart, so that users wouldn't accidentally crash programs they were running. The key sequence was only published in technical manuals because its necessity quickly became apparent. Other artifacts of ancestral PCs lurk, Easter-egg-like, within modern systems. By holding down the alt key while typing on a keyboard's number pad a three-digit numerical value for a character in the extended ASCII IBM PC character set, the character will be displayed when the "alt" key is released. Hold down the "alt" key and type 064, for example, and you'll have an @ sign. When the IBM PC went on sale, systems started at US$1,565 - without a monitor. Less than a dozen software programs were available for the machine, including the VisiCalc spreadsheet program, the EasyWriter word processor, Peachtree Software's General Ledger accounting program, and a version of Colossal Cave Adventure, a text-based exploration game. One big break for the IBM PC came in 1983, when Lotus 1-2-3 debuted and inherited the crown of spreadsheet supremacy from VisiCalc. "The PC was a nonentity until about 1983 or '84. Until Lotus 1-2-3 came out, the PC did nothing," said Joe Tartaglia, president and co-founder of New York-based computer services and software design shop High Caliber Systems. Tartaglia, who began programming using punch cards back in the 1970s, recalls buying his first computer in 1980 - an Apple II that cost over $7,000, including accessories. "I got that money back very quickly. I was used to timesharing," he said. "This guy said to me, 'You can actually get your own computer with your own compiler and everything.' I said, 'You're joking.' He said, 'No, really, you can. Your own computer.' It was a miracle." When the IBM PC debuted, "it was sort of an oddity. It was interesting that a company that size had gotten into the business. There was a lot of press about how Big Blue had gotten in and legitimized the market. The fact that they did get involved made it better for everyone, including Apple," he said. "But what people forget is that it didn't happen overnight. It's not like (IBM) released the PC and that was the end of everything else and everyone became a clone a day later. ... It was 1984 before the PC started to affect things." By then, in New York, Wall Streeters and others in the financial industry were clamoring for Lotus 1-2-3 - and for IBM PCs to run it on. 1984 was also when freelance Web producer Ari Feldman got his first computer, IBM's home-user-targeted PCjr. "It opened up an entire world for me," he wrote via e-mail. "On that beige beauty, I learned how to program, I learned DOS, I learned major applications like Lotus 1-2-3 ... and how to trouble-shoot and fix my own problems." A full, "advanced" set-up for the 1981 IBM PC cost $4,500, and included a system unit, monitor, keyboard, 256B of RAM, two disk drives, and a printer. Today that would buy you a full-spec Intellistation M-Pro workstation capable of working with professional 3D graphics. "(My first) machine has 128KB of RAM, was capable of displaying 16 colours in graphics mode, and could play sound in three voices with seven octaves of range. I look back in amazement as I type this e-mail on a 3-year-old iMac that has over 160 times the RAM, can display millions of colours, and can record and playback CD-quality digital sound," Feldman wrote.