The Altair 8800 — The Personal Computer That Started on a Magazine Cover

The Altair 8800 was a microcomputer built around the Intel 8080 by MITS (Micro Instrumentation and Telemetry Systems), a small company in Albuquerque, New Mexico. It was introduced in the January 1975 issue of Popular Electronics, which put it on the cover and carried a construction article by MITS's H. Edward Roberts and William Yates. Most buyers got it as a kit of parts and soldered it together themselves. It had no keyboard and no screen: programs went in through a row of switches on the front panel and results came out as patterns of LEDs. Even so, it caused a sensation for one reason — an individual could own a computer.

The January 1975 issue

The cover line read "PROJECT BREAKTHROUGH!", followed by "World's First Minicomputer Kit to Rival Commercial Models..." — the magazine's own billing. The editorial in the same issue was headed "THE HOME COMPUTER IS HERE!" and announced, with evident pride, a minicomputer project priced within reach of many households.

According to that editorial, the magazine had already turned down three computer project proposals because they would have been little more than demonstrators with blinking LEDs. The breakthrough, it said, was the availability of the Intel 8080, which it described as the highest-performance single-chip processor then available.

The construction article, "Altair 8800 Minicomputer, Part I", gave these specifications:

This was Part I; the second part was promised for the following month's issue.

The price

Postage was extra, and orders went to MITS's Albuquerque address. The article put the complete kit in a colour-TV receiver's price class, under $400. Later references also give $439 for the kit and $621 assembled, but the January 1975 article itself lists the prices above.

The machine on the cover

According to the Computer History Museum, the computer had not been finished, or even named, when the editor Les Solomon solicited the article; the magazine photographed an empty box and chose the name "Altair." The Centre for Computing History in the UK says the first prototype was lost in transit during a strike at the shipping company, so the machine on the cover was a hastily assembled replacement. The same organisation says the issue went on sale in the week before Christmas 1974.

The flood of orders

The Computer History Museum says that an avalanche of orders followed the cover. Its 1995 oral history with Ed Roberts covers the challenge of responding to thousands of unforeseen orders as the Altair sold far beyond projections. The Centre for Computing History reports that Roberts had originally forecast total sales of 800 machines, but that MITS received 1,000 orders in February 1975 alone.

In the same interview Roberts describes the Altair "ecosystem": the large network of people and companies who created add-on products for the computer. Memory, input/output and disk boards were built to plug into its bus, and the Altair became less a single product than a platform for peripherals.

What started with the Altair

The best-known consequence was in software. Bill Gates and Paul Allen wrote a BASIC for this machine, and that led to the founding of Microsoft; the story is told there. It was also the moment when BASIC, born at Dartmouth in 1964, began running on a machine an individual could own.

In hardware, two years later in 1977, the Apple II arrived as a finished machine that worked without opening the case and displayed colour on a television. From a box of switches and LEDs to a machine you could use as soon as you bought it — the shape of the personal computer changed from there.

MITS itself did not last. The Computer History Museum's catalogue entry says MITS was sold to Pertec in 1977, so the Altair line was short-lived. The same entry calls the Altair widely credited with sparking the personal computer revolution, while noting that home-brew experimental systems existed well before it; none had the Altair's wide-reaching popularity. The accurate claim is therefore not "the first personal computer" but the first computer kit to reach a wide public.

For the microprocessors that led to the 8080, see the Intel 4004; for the companies, Intel and Microsoft; for the person, Bill Gates; and for the period as a whole, the hardware timeline and the overview timeline.