OFFICE workers across the globe will today celebrate, or perhaps curse, the 25th anniversary of a device that changed the world: the mass- market personal computer, or PC.

On this day in 1981 — the year Ronald Reagan entered the White House and Margaret Thatcher stunned Britain by raising taxes — IBM launched the 5150, a machine boasting a 4.77Mhz processor (about 650 times slower than today’s PCs), up to 256kb of memory (about 8,000 times less than today’s PCs) and an optional floppy drive with 160kb of capacity (barely enough for a Word document).

The PC was priced at $1,565, about £2,500 in today’s money, and made its debut to a sceptical public. As one analyst joked: “IBM bringing out a personal computer would be like teaching an elephant to tap-dance.”

But the elephant did dance, and the 5150 was a huge success. It featured an enhanced version of Microsoft’s BASIC programing language, developed by a certain William Gates, and an 83-key adjustable keyboard. Unlike many other computers then, the keyboard and monitor were not built-in but attached — an industry standard that Apple has tried to counteract with its wireless Bluetooth iMacs.

The IBM PC was not the first personal computer: the Apple II came out in 1977 and the Atari 800 in 1979, but both used proprietary components and failed to develop sales into the mass market.

In contrast, IBM used an Intel processor and Microsoft software, essentially allowing rival companies to clone its product. This move was a result of IBM simply being in a hurry, rather than any grand strategy.

“The original desktop PC was a long way from the user-friendly devices we use today,” said Keith Jones, the managing director of PC World — citing research showing that about a third of Britons say that the PC is the one technological innovation that they could not live without, beating the mobile phone and the washing machine. “Compared with today’s models, the original PC had marginal productivity benefits. But those products sowed the seeds of a revolution,” he said.

But not everyone loves the PC — which, before the launch of the 5150, was known simply as the microprocessor. The 5150 began the era of Moore’s Law — or rapid obsolescence — along with repetitive strain injury, internet porn, timewasting viruses and countless other forms of PC frustration.

Even making PCs has also become a commodity business. In 2004 IBM sold its PC business to the Chinese — a fitting end, some believed, to a world-changing product that had largely been an accident. As The New York Times noted back in 1981: “The speed and extent to which IBM has been successful has surprised many people, including IBM itself.”

As the revolution rolls on, the one billionth computer was sold in 2002. The two billionth will be sold some time next year.

()

Why we love computers

1 You’ve got mail. OK, so half of it is offering you cheap Viagra and the other half is warning you about internet scams offering you cheap Viagra, but it’s nice to feel wanted

Times Recommends

• ‘Thousands of Tamils dying’ in Sri Lanka camp
• Jackson 'rebuilt his nose before he died'
• Tehran: militiamen attack protesters