Ohio Scientific Advert - July 1977

Ohio Scientific seemed to only ever advertise variations of its Challenger series of sometimes-fridge-sized microcomputers, however here is the exception that proves the rule - the Model 500.

It appears to be aimed at the student market, where it could be coupled with a terminal for "student instruction", but it was also pitched as a way of making a terminal intelligent by acting as a pass-though gateway where, if it was on, it could talk to incoming calls on a modem. Failing that, it could also be an "ultra-powerful scientific calculator".

The Model 500 was available as a bare board for $298, which is about £1,730, or as the pre-built 500-1 unit of the advert for $429, or about £2,480 now.