Compucorp Advert - May 1979

Compucorp Limited was the UK offshoot of Compucorp Inc, a California-based calculator manufacturer which was a division of Computer Design Corporation, a company which itself was a spin-out from Wyle Laboratories.

Formed in 1968, when Computer mostly meant a person who does calculations, Computer Design Corporation's giant desktop calculators, which were produced as OEM products for other companies such as Monroe, Ricoh and the UK's Sumlock, were so successful that by 1971 the company decided it was going to start selling its calculators under its own name.

However, it, like many other calculator companies of the day, suffered during the "Calculator Wars" of the mid 1970s, a process of company attrition and price-wars caused by improving technology, the introduction of cheap four-function calculators, and the killer blow, which was delivered when Texas Instruments - a major supplier of calculator chips - entered the market and started selling its own calculators for less than the cost of the parts supplied to its competitors.

Like Commodore, another company which itself had been producing calculators since it launched the Commodore C110 - a re-branded Bowmar - in 1971, Compucorp decided to branch out into the burgeoning business microcomputer market, and launched a range of machines actually based on its calculator hardware.

The company struggled financially and by late 1975 had entered Chapter 11 bankruptcy protection, however its association with the Diablo - a company co-founded by George Comstock who would later go on to set up Durango - led it towards building word processing systems, which in turn led to some additional investment in the company^[1].

This, along with its on-going OEM calculator business, was enough to keep it afloat long enough to launch its 600 range in 1979, which included the 610 and 625 - both of which were Z80-based micros with an S-100 bus, and which clearly show a direct lineage in form-factor back to Compucorp's desktop calculators^[2].

The entry-level 610, which came with 48K RAM, a 150K floppy disk drive, and a tiny built-in VDU retailed for £3,890 plus VAT, which is about £31,900 in 2026.

The company didn't last much longer though. The arrival of the IBM PC in 1981, combined with Compucorp's dwindling calculator sales, saw the end of its operations in 1984, coincidentally the same year that Texas Instruments - the architect of the destruction of many calculator companies before - also exited the microcomputer business.