Apple is said to have revolutionized the world of personal computing twenty years ago with the launch of the Mac. Tomorrow will see the company celebrate the Mac's twentieth anniversary.

Although Jobs is the joint founder of Apple, the Mac was not his brainchild. The man behind the Mac was actually employee 31, Jef Raskin.

Raskin's story is outlined in a chapter called the Making of Macintosh in Owen Linzmayer's Apple Confidential 2.0, the second edition of which has just been published.

In 1979 Raskin was approached by the then Apple chairman, Mike Markkula, to develop a low-cost game machine. But Raskin had other ideas. He recalls: "There was this thing that I'd been dreaming of for some time, which I called Macintosh. The biggest thing about it was that it would be designed from a human factors perspective, which at the time was totally incomprehensible."

Raskin envisioned a computer for the "Person in the Street," known as the PITS, for short. "There were to be no peripheral slots so that customers never had to see the inside of the machine (although external ports would be provided); there was a fixed memory size so that all applications would run on all Macintoshes; the screen, keyboard, and mass-storage device (and, we hoped a printer) were to be built-in so that we could control the appearance of characters and graphics."

The computer would be contained in an all-in-one case without cables, and portable. Raskin envisaged a weight of just under 20lbs and an internal battery providing up to two hours of operation. His wish list also included an 8-bit microprocessor with 64K of RAM, one serial port, a modem, real-time clock, printer, 4.5-inch diagonal screen with bitmapped graphics, and a 200k, 5.25 floppy-disk drive all built in.

Raskin also desired a new interface in which everything – writing, calculating, drafting and painting, would be accomplished in a graphical word processor-type environment with a few consistent and easily learned concepts.

While that may not sound like the Mac we know, Raskin's reasoning was that there should be no modes or levels, and this is a concept that has endured.

Jobs, however, was not so endeared to the concept. According to Raskin: "Jobs hated the idea. He ran around saying 'No! No! It'll never work.' He was one of the Macintosh's hardest critics, and was always putting it down at board meetings. He was dead set against the Macintosh for the first two years."

But Jobs did eventually become convinced that the Mac would work, and when he did, according to Raskin: "He started to take over."

Jobs takes over

Having taken over the management of the hardware development side of the project, Jobs underestimated the amount of work that needed to be done to complete the Mac, and the time it would take and the Mac missed its first deadline of 1982.

Eventually, to save time, the Mac ended up sharing the same microprocessor as the Lisa, and could therefore share some of the Lisa technologies and software, speeding up development. Jobs steadfastly refused to make the Mac compatible with the Lisa, or vice versa.

It soon became apparent that the Mac would share so much of the Lisa's interface that a mouse was a necessity, much to Raskin's dismay – he was leaning towards a lightpen or joystick as a graphical input device.

But Raskin was the one who opted for the one-button format – he felt that it would be much easier for novices.

Raskin resigned from the project in February 1982 after Jobs declared: "I'm taking over software, and you can run documentation."

Enter IBM

Jobs was hell-bent on proving that he could produce a better computer than the Lisa, but it was becoming apparent that the real competition was coming from IBM.

IBM introduced its Personal Computer on August 12, 1981. The market had responded favourably and the Mac team recognised that it had better get their product out the door quickly, so as not to miss the window of opportunity.

But the second deadline – May 1983 – came and went and the Mac still wasn't ready.

Finally, after spending $78 million in development costs, Apple introduced the Macintosh at the annual shareholders meeting on January 24, 1984.

The crowd went wild when a picture of the Mac appeared on screen.

The Mac took $500 to build and with Apple's standard mark-up the price should have been $1,995. But the then chairman, John Sculley, had spent so much on marketing the new product – including the 1984 commercial that would be broadcast in the Super Bowl – that the Mac was priced at $2,495 (£1,353).

This text is taken from Apple Confidential 2.0, the second edition of the essential Apple compendium costs £15.99 from Amazon. A fuller transcript appeared in the January edition of Macworld.