The Altair 8800: The Kit Computer That Sparked the Personal Computer Revolution

The January 1975 issue of Popular Electronics featured a microcomputer on its cover with the headline "World's First Minicomputer Kit to Rival Commercial Models." The machine was the MITS Altair 8800, built around the Intel 8080 microprocessor and offered as a kit for $397 — equivalent to about $2,300 in 2026 dollars. In a more assembled form it cost $439. Either way, you got a metal box with row after row of toggle switches on the front panel, blinking lights, and absolutely nothing else. No keyboard. No screen. No way to store programs. No software.

What You Got for $397

The Altair 8800 was, in most practical senses, barely a computer. To program it, you toggled binary code — the raw machine language of the Intel 8080 — directly into its memory using the front panel switches, one byte at a time. You could tell whether your program had run correctly by reading the pattern of lights on the front panel. If you turned off the machine, your program was gone. The process was tedious enough that most users spent more time loading programs than running them.

And yet it sold out instantly. MITS, a small calculator company in Albuquerque, New Mexico, had ordered 200 units from its manufacturer and received over 2,000 orders within the first month of the magazine appearing on newsstands. By the end of 1975, MITS had sold tens of thousands of Altairs. The demand revealed something the computing establishment had completely missed: hobbyists, hackers, and enthusiasts were desperate for their own machines, and they were willing to work through extraordinary inconveniences to have them.

Two Harvard Students Take Notice

Two of the people who saw the Popular Electronics cover were Bill Gates and Paul Allen, students at Harvard. Allen burst into Gates's dorm room with the magazine, and both men immediately recognized the significance. The Altair needed software — specifically, it needed a programming language that would make it programmable without toggling in binary code switch by switch.

Gates and Allen called MITS and told them they had written a BASIC interpreter for the Altair. They had not, but they needed the contract to exist before they could justify writing it. MITS agreed, and Gates and Allen spent the following weeks frantically writing Altair BASIC, an interpreter for the BASIC programming language, on a Harvard mainframe using an Intel 8080 simulator they wrote themselves — without ever touching an actual Altair until the day Allen flew to Albuquerque to demonstrate it.

The demonstration worked. MITS agreed to license and distribute Altair BASIC. Gates dropped out of Harvard. Allen left Honeywell, where he had been working. They formed a company called Micro-Soft — later Microsoft — in 1975, initially located in Albuquerque near MITS. Altair BASIC became the foundation of the software that eventually powered the IBM PC and, through it, the entire PC industry.

From Kit to Industry

The Altair's commercial success convinced other entrepreneurs that there was a real consumer market for personal computers. In 1976, Steve Wozniak and Steve Jobs introduced the Apple I at the Homebrew Computer Club, a Bay Area hobbyist group that had formed partly in response to the Altair. The Apple I was a fully assembled circuit board — a step beyond the Altair's kit form — and the Apple II, released in 1977, added a keyboard, color graphics, and expansion slots. It became the first genuinely mass-market personal computer.

The IBM PC arrived in 1981, using Microsoft's operating system (MS-DOS) on Intel processors — a direct lineage from the Altair, whose Intel 8080 processor was the ancestor of the 8086 in the IBM PC. The architecture that IBM standardized became the dominant computing platform for decades, spawning the "IBM compatible" or "PC" standard that still defines most of the world's computers.

The Altair 8800 was not a very good computer. It was difficult to program, limited in capability, and required significant technical sophistication just to do anything with it. But it was available, it was affordable, and it came first — and in technology, as in many domains, arriving first with a working product at the right moment is often what shapes the future that follows.