The original PC was an IBM attempt to get into the small computer market then dominated by the Commodore PET, Atari 8-bit family, Apple II and Tandy Corporation's TRS-80s, and various CP/M machines.[1] IBM's first desktop microcomputer was the IBM 5100 introduced in 1975, but its price was high compared to microprocessor-based computers.
Rather than going through the usual IBM design process, a special team was assembled with authorization to bypass normal company restrictions and get something to market rapidly. This project was given the code name Project Chess.
The team consisted of twelve people headed by Don Estridge and Chief Scientist Larry Potter. They developed the PC in about a year. To achieve this they first decided to build the machine with "off-the-shelf" parts from a variety of different original equipment manufacturers (OEMs) and countries. Previously IBM had developed their own components. Secondly, they decided on an open architecture so that other manufacturers could produce and sell peripheral components and compatible software. IBM also sold an IBM PC Technical Reference Manual which included a listing of the ROM BIOS source code.[2]
At the time, Don Estridge and his team considered using the IBM 801 processor and its operating system that had been developed at the Thomas J. Watson Research Center in Yorktown Heights, New York (The 801 is an early RISC microprocessor designed by John Cocke and his team at Yorktown Heights.) The 801 was at least an order of magnitude more powerful than the Intel 8088, and the operating system many years more advanced than the DOS operating system from Microsoft, that was finally selected. Ruling out an in-house solution made the team’s job much easier and may have avoided a delay in the schedule, but the ultimate consequences of this decision for IBM were far-reaching. IBM had recently developed the Datamaster business microcomputer which used an Intel processor and peripheral ICs; familiarity with these chips and the availability of the Intel 8088 processor was a deciding factor in the choice of processor for the new product. Even the 62-pin expansion bus slots were designed to be similar to the Datamaster slots. Delays due to in-house development of the Datamaster software also influenced the design team to a fast track development process for the PC, with publicly-available technical information to encourage third-party developers. [3]
Other manufacturers soon reverse engineered the BIOS to produce their own non-infringing functional copies. Columbia Data Products introduced the first IBM-PC compatible computer in June 1982. In November 1982, Compaq Computer Corporation announced the Compaq Portable, the first portable IBM PC compatible. The first models were shipped in March 1983.
Once the IBM PC became a commercial success the PC came back under the usual IBM management control, with the result that competitors had little trouble taking the lead from them. (In this regard, IBM's tradition of "rationalizing" their product lines—deliberately restricting the performance of lower-priced models in order to prevent them from "cannibalizing" profits from higher-priced models—worked against them).
Although IBM's launch of the Personal Computer (IBM 5150) in 1981 set the industry standard for personal computing, IBM had introduced a variety of small computers for individual users several years before that. So while now is certainly an appropriate moment to salute the legendary IBM PC on its 20th birthday, it's also a good time to take a brief look back at some of the pioneering IBM products that immediately preceded it.
Sources:
http://en.wikip edia.org/wiki/IBM_PC
Answered by
ayisha
at
4:36 PM on August 08, 2008
