Equinox/Parasitic Advert - October 1977

The Equinox 100 was a Zilog Z80 or Intel 8080-based system with an industry-standard S-100 bus - the most popular bus standard of the day.

It was built by Parasitic Engineering of Albany, California, which had started out as a supplier of "debugging kits" for the Altair 8800 - these were upgrade kits for the Altair's power supply which helped to reduce noise on its S-100 bus.

The company name came about because MITS - the manufacturer of the Altair - had built its business model on selling its micro at a break-even price, whilst hoping to make up the profit by selling plug-in boards and extras.

However, as other companies starting producing their own often-improved boards and upgrades, MITS came to consider them as "parasite companies", which Parasitic founder Howard Fullmer referenced when naming his company.

In early 1978 it was estimated that there were more than fifty manufacturers in the US producing all sorts of upgrades and plug-in cards for S-100 systems, from extra memory to laboratory interfaces and speech synthesizers.

The Equinox was launched in the UK at the Mini-Micro exhibition in early 1978, held at the US Government Trade Centre in London. The complete micro - including 32K RAM and dual floppy disks - retailed for just under £3,000, which is about £24,100 in 2026.

Previously available in the US as a "mainframe kit" for $799 - about £5,030 in 2026, the built version of the Equinox used the WünderBuss motherboard, designed by well-known electronics engineer George Morrow^[1]. Morrow also had a hand in the design of the actual Equinox 100 micro itself.

An advert for George Morrow's WünderBuss, from Morrow's Micro-Stuff, and sold via the Thinker Toys brand. From Byte, July 1977

George Morrow would later set up Morrow Designs, which produced the Decision series of micros in 1982.