ATARI 850 - Re
v 7

The Atari 850 is a port expander which includes four RS-232 ports and one Centronics parallel port.

It was marketed for use with the Atari 400 and 800 but could be used with pretty much any 8-Bit Atari microcomputer.

It is exceptionally boring visually but to its credit works a treat.

Atari 850
Atari 850 Motherboard
     
 
Unit pictured has been sold and its location is unknown.