The History of Personal Computing

Cromemco Z-1

Cromemco was founded in Mountain View, CA by two Stanford Ph.D. students in 1974, Harry Garland and Roger Melen. It received its name in honor of their residence at Stanford University, Crothers Memorial, which was a dormitory reserved for engineering graduate students. The two had already been working together on a series of articles for Popular Electronics magazine.The articles were for non-computer electronic hobbyist projects. In late 1974, Roger Melen was visiting the New York editorial offices of Popular Electronics and he saw the prototype of the MITS Altair 8800. He was so impressed with it that he immediately changed his next flight to go to Albuquerque, NM. There he met with Ed Roberts, president of MITS, and Roberts encouraged Melen to develop add-on products for the Altair. Continue reading Cromemco Z-1…

Launched in 1976, the MOS Technology KIM-1 (KIM being short for Keyboard Input Monitor), was a small 6502-based single-board computer. MOS Technology was a semiconductor designer and manufacturer based in Norristown, Pennsylvania. It is most famous for the 6502 microprocessor. In late 1976, Commodore Business Machines (CBM) acquired MOS.

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The COSMAC ELF was an RCA 1802 microprocessor-based computer based on a series of construction articles in Popular Electronics magazine in 1976 and 1977. Through the back pages of electronics magazines, both Netronics and Quest Electronics offered low-priced kits that were based on this design. The system was a very early personal computer. It was operated without built-in ROMs and programs were entered directly with help of the CPU integrated DMA.

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Sol-20 with its distinctive blue color and wooden sides

The Altair, the IMSAI, and then later, many other microcomputers created a cottage industry. MITS and IMS Associates only offered a limited number of products and upgrades, if you could get them given the high demand for them at the time. Gary Ingram and Bob Marsh, two friends in Berkeley, California, saw this as a business opportunity. Marsh, an active member of the Homebrew Computer Club, would hear complaints about the Altair at every club meeting, so with Ingram, they decided to form a company called Processor Technology Inc. Their first product was a reliable, static 4 kB memory board for the Altair, as they knew that MITS was producing an unreliable dynamic version. Processor Technology’s 4KRA RAM board became an almost instant hit and launched the company into a thriving business. Ingram and Marsh were then able to move out of their garage workshop and into a large industrial facility.

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