MITS Altair 680 - The Small Wonder of the Micro-World

This advert for the Altair 680 from MITS (Micro Instrumentation and Telemetry Systems) appeared in Popular Electronics at the end of 1976, about a year after this computer was first announced back in November 1975[source: http://www.computercloset.org/MITSAltair680.htm].

The 680 was a small programmable computer, and was one of the first three based on the [!6800|Motorola 6800] CPU. 

It followed on from the Altair 8800 of January 1975 - a machine based on [!8080|Intel's 8080] CPU, and the machine which launched [@Microsoft].

However, unlike its predecessor, it only supported three expansion slots, and despite using the same edge connector it wasn't actually S-100 bus compatible, which meant none of the add-in cards launched on the market since the debut of the Altair 8800 would work. 

It's thought that only five boards were ever made, and for that reason, as well as its lack of memory - it shipped with 1K of RAM - its lack of keyboard or video output, and a general market shift towards Intel's 8080 or [!Z80|Zilog's Z80], the 680 did not sell very well[source: https://www.retrotechnology.com/restore/altair680.html].

That's despite the fact that it retailed for a not-unreasonable $625 plus tax - about [[420|1976]] in [[now]] money - although a version with extra memory and a copy of "680 BASIC" was just over double that at around [[875|1976]] in [[now]].

[@MOS Technology]'s 6501 - a relative of the 6502 - was pitched as a much cheaper, drop-in replacement for the 6800. 

Even though it had the same pin-out, it was not a copy (its internals were completely different), however its external similarities gave Motorola's lawyers cause to sue for intellectual property infringement - a situation not without merit as it had been developed by several ex-Motorola engineers including Bill Mensch and Chuck Peddle.

Luckily for MOS (and ultimately [@Commodore] and large chunks of the 1980s microcomputer industry), the settlement with Motorola involved it dropping the 6501, but keeping the 6502.

This didn't bother Peddle that much as he'd designed the 6501 as an "in your face" to Motorola, and hadn't really intended to sell it to anyone[source: https://www.commodore.ca/commodore-history/the-rise-of-mos-technology-the-6502/].
