The Altair 8800: Catalyst of the Microcomputer Revolution

The Altair 8800: Catalyst of the Microcomputer Revolution

 

The Altair 8800, designed by MITS (Micro Instrumentation and Telemetry Systems) in 1974, is a microcomputer that was based on the Intel 8080 CPU. Following its introduction on the cover of the January 1975 issue of Popular Electronics magazine, interest in the Altair 8800 surged, and it was sold via mail order through advertisements in Radio-Electronics and other hobbyist magazines. According to Harry Garland, the Altair 8800 sparked the microcomputer revolution of the 1970s. It became the first commercially successful personal computer, and the computer bus designed for the Altair became the S-100 bus, a de facto standard. The first programming language for the Altair was Altair BASIC, the inaugural product of Microsoft.

Since the Altair 8800 did not provide a built-in screen or video output, it had to be connected to a serial terminal, such as a VT100 compatible terminal, to be used as an output device. This required the installation of a serial interface card, and in the absence of a terminal, the Altair could be programmed using the switches on its front panel.

 

History

MITS's first kit was a "tracking device for model rockets" project that appeared in the September 1969 issue of Model Rocketry magazine. Ed Roberts and Forrest M. Mims III, while working at the Air Force Weapons Laboratory at Kirtland Air Force Base, decided to use their electronics expertise to create small kits for model rocket enthusiasts. In 1969, Roberts and Mims, along with Stan Cagle and Robert Zaller, founded Micro Instrumentation and Telemetry Systems (MITS) in Roberts's garage in Albuquerque, New Mexico, and began selling radio transmitters and instruments for model rockets.

 

Calculators

The model rocket kits saw some success, and MITS sought to try kits that would appeal to a broader range of hobbyists. The November 1970 issue of Popular Electronics featured Opticom, a kit made by MITS that transmitted sound via an LED beam. Mims and Cagle lost interest in the kit business, and Roberts, after buying out his colleagues' shares, began developing calculator kits. Electronic Arrays announced the EAS100, a set of six Large Scale Integrated (LSI) circuits that could be used to build a four-function calculator. The MITS 816 calculator kit was created using this chipset and appeared on the cover of the November 1971 issue of Popular Electronics. The kit sold for $175, with an assembled version priced at $275. Forrest Mims would go on to write assembly instructions for this kit, as well as many others over the next several years, often receiving a copy of the kit as compensation for his work.

The calculators were successful, and several improved models followed. The MITS 1440 calculator was featured in the July 1973 issue of Radio-Electronics. It featured a 14-digit display, memory, and square root functionality. The kit was priced at $200, with an assembled version selling for $250. MITS later developed a programmer unit that could connect to either the 816 or 1440 calculators to create programs up to 256 steps.

In 1972, Texas Instruments began producing its own calculator chips and started selling complete calculators for less than half the price of competing commercial models. This significantly impacted many companies, including MITS, and Roberts struggled to reduce the company's debt, which had grown to $250,000.

 

Test Equipment

In addition to calculators, MITS produced various test equipment kits, including an IC tester, waveform generator, digital voltmeter, and several other instruments. To meet the growing demand, MITS moved to a larger facility at 6328 Linn NE in Albuquerque in 1973, which included a wave soldering machine and an assembly line.

 

Popular Electronics

In January 1972, Popular Electronics merged with another Ziff-Davis magazine, Electronics World. Changes in the editorial team led many authors to write for the competing magazine, Radio-Electronics. Some of the best construction projects appeared in Radio-Electronics in 1972 and 1973.

In 1974, Art Salsberg became the editor of Popular Electronics. Salsberg wanted to regain the leading position in electronics projects. Impressed by Don Lancaster's TV Typewriter (featured in the September 1973 issue of Radio-Electronics), Salsberg wanted a computer project for Popular Electronics. Don Lancaster created an ASCII keyboard for the April 1974 issue of Popular Electronics. The editorial team was evaluating Jerry Ogden's computer trainer project when the Mark-8, an 8008-based computer by Jonathan Titus, appeared on the cover of the July 1974 issue of Radio-Electronics, causing the project to be put on hold. Popular Electronics assigned Jerry Ogden to write a column called "Computer Bits," which began in June 1975.

One of the editors, Les Solomon, knew that MITS was working on an Intel 8080-based computer project and thought Roberts could deliver the popular January issue project. Unlike the TV Typewriter and Mark-8 computer projects, which were essentially detailed schematics with bare printed circuit board sets, hobbyists faced the challenge of sourcing all the integrated circuits and other components. The Popular Electronics editorial team wanted a complete kit with a professional appearance.

Ed Roberts and his chief engineer, Bill Yates, completed the first prototype in October 1974 and shipped it via express rail to Popular Electronics in New York, but it failed to arrive due to a strike at the shipping company. Solomon, however, had several photographs of the machine, and the article was written based on them. Roberts began constructing a replacement. The computer shown on the magazine cover was an empty box with switches and LEDs on the front panel. The finished Altair computer featured a completely different circuit board layout than the prototype shown in the magazine. The January 1975 issue appeared on newsstands a week before Christmas 1974, and the kit was officially (though not yet practically) available for sale.

 

Origin of the Name

A typical MITS product had a generic name, like "Model 1440 Calculator" or "Model 1600 Digital Voltmeter." Ed Roberts, busy finalizing the design, left the naming of the computer to the editors of Popular Electronics.

One origin story, as Les Solomon later told an audience at the first Altair Computer Convention in March 1976, involved his 12-year-old daughter, Lauren. "She said, 'That's where the Enterprise is going tonight,'" referring to the Altair system mentioned in an episode of Star Trek. The episode is likely "Amok Time," the only episode in the original series where the Enterprise crew goes to Altair (Six).

Another explanation is that the computer was originally going to be named PE-8 (Popular Electronics 8-bit), but Les Solomon found it too boring, and along with Alexander Burawa (associate editor) and John McVeigh (technical editor), decided it should be named after a star, given the significance of the event. McVeigh had previously read about young astronauts on a mission to the Macedonia Kandeweller space station named after the star Altair A, located 16 light-years away, beyond the Sun. The trio decided that "Altair 8800" was the perfect name.

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This detailed history highlights the journey of the Altair 8800 from concept to market, showcasing its pivotal role in the birth of the personal computer industry and the microcomputer revolution.