IBM Personal Computer: Difference between revisions

 

Born in August 1981 due to the [[Apple II]]'s success, the IBM Personal Computer (dubbed the "5150" in IBM's internal numbering system) was IBM's official entry into the desktop computer system market, and by far their most successful. Earlier attempts, like the 5100 desktop APL machine and the DisplayWriter word-processing machine, hadn't taken off, and IBM needed something ''fast'' to compete with Apple. Bypassing the IBM bureaucracy, in 1980 they tasked a team of engineers in an IBM office in Florida with developing the new machine, and gave them unusual amounts of freedom in developing the new system. It was built almost completely out of off-the-shelf parts and had generous amounts of expansion capability. As for the processor, the team settled on Intel's 16-bit 8088. The 8088 was chosen mainly for cost and time-to-market reasons. To ensure a steady supply of 8088s, IBM and Intel recruited Advanced Micro Devices (AMD) to act as a second source, a decision that would have some importance later.

 

== History ==

The other big influence on the IBM PC's design was the world of ''S-100 machines'', which were based around the Intel 8080 (or, later the Zilog Z80) and the "S-100" bus that had been introduced in the pioneering Altair 8800. These machines ran an OS called ''CP/M'', which had been invented by a programmer named Gary Kildall in 1974 and was based indirectly on Digital Equipment Corp.'s ''RSX-11'' [[Operating System]] for the PDP-11. While they weren't nearly as slick as the [[Apple II]], S-100 machines were popular with hobbyists and businesses alike, and several CP/M applications for businesses, like ''WordStar'' and ''dBASE'' were making inroads.

 

 

=== The Rise of the Clones ===

At first, the IBM PC didn't have much to offer home users and gamers. It was new, expensive, not as good with graphics as the Apple II or the Atari 800, and was directed squarely at business users. However, IBM's name on the machine made it a safe buy for businesses that already used IBM hardware, and they ended up buying the machines in droves. The machine's open design sparked a huge third-party expansion market, with dozens of vendors selling memory expansion boards, hard drive upgrades and more. It wasn't long until other computer makers started examining the PC's design and figuring out how to make clones of the machine that could run PC software without issues. The one thing stopping them, however, was the ROM. IBM had a copyright on what they called the "ROM BIOS", and while cloning the hardware was easy, cloning the ROM would be much harder, with few vendors able to get it completely right. It wasn't until Compaq introduced the Portable in 1983 that a truly 100% IBM compatible PC was available, and after that, software houses such as Phoenix and AMI followed suit, opening the floodgates to an entire industry of low-priced PC compatibles.

 

 

=== IBM Tries to Win Back the Crowd ===

In 1986 Compaq beat IBM to the punch with the first PC to use the new, 32-bit 80386 processor. Between the clone armies and Compaq's meteoric rise, IBM decided that if it couldn't compete on price, it would compete on features, and introduce a new standard that they alone would control.

 

 

=== Wintel Comes And Wins ===

After years of being confined to what were basically fleet sales, IBM discontinued the PS/2 line and MCA in the mid-1990s, preferring instead to concentrate on the revived "IBM PC" brand (new, ISA/PCI-based machines sold as business desktops) and the highly successful ThinkPad line of notebooks, which was introduced in 1992. This marked the end of IBM's dominance of the PC clone market, with the balance of power now shifted to Microsoft, Intel and the clonemakers.

 

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[[Category:IBM Personal Computer]]