Recently we discussed, and hoglet and I played with, the Essex Tiny BASIC Computer Board. That board uses an INS8073 SC/MP microprocessor, with on-chip Basic ROM. Prior to that, the original SC/MP could run an earlier version of the Basic (NIBL) using a conventional ROM. It turns out there was a single board computer offering just that - very much a predecessor of the Essex.
Here it is, the Nibbler, from Digi-Key, and from 1978, in a series of 7 videos from Hello World. (Digi-Key is now known as Digikey.) Be sure to check the video descriptions for interesting links.
In the mid 1970s, National Semiconductor released the “Simple, Cost Effective, Micro Processor” (SC/MP), probably better known as the SCAMP. Digi-Key released a single board computer based on the SC/MP II (INS8060) which they offered for sale from June 1978 through June of 1979 and then it completely disappeared from the face of the earth.
You’ll notice 16 RAM chips are needed to supply that 2K of RAM - later boards used 2114 chips, which are 1k x 4bits. The Essex board uses a single 2k x 8 chip.
More on the Nibbler over on the Vintage Radio forums:
Thanks to @hoglet for the pointers to this.