This is the famous ELF II computer

The apparently-famous ELF II from Netronics Research and Development Limited of New Milford, Connecticut, was one of relatively few micros around which used RCA's COSMAC - COmplementary Symmetry Monolithic Array Computer - 1802 CPU, a chip which was aimed at the video developer market created by games like Atari's Pong.

Its name was apparently based on the previous COSMAC ELF - a similar RCA 1802 microcomputer built in parts via a series of articles which ran in Popular Electronics magazine in 1976 and '77[source: https://en.wikipedia.org/wiki/COSMAC_ELF].

The bare-board system - in an unusual cheese-wedge configuration - was available from the UK sole importer H. L. Audio Limited for £108, which is around [[108|1979]] in [[now]]. It came with 256 bytes - although that was expandable to 64K - plus a decent hexadecimal keyboard for input.

It was also fairly unusual for a bare-board in coming with a built-in expansion bus, offering five slots. However, the minimal system didn't actually come with any sockets soldered in, so that was a job left for the purchaser.

There might be other stuff mentioned in the advert, but it's in the tiniest text which is barely readable even in the original magazine.