Some Centronics compatible printers did not have internal interface slots. This required me to design a version that was an external standalone version of my popular Centronics Printer Interface to ICL System Ten and ICL System 25 Mini-Computers.
This board/box plugged externally into various Centronics and compatible Printers such as the Centronics 1551S, Centronics Band Printers, and the Microline Series.
My board used a pair of Motorola MC68705P3S’s. Each microprocessor had 1.7KB of internal EPROM.
The first picture shows a pre-production version which used an external power-pack for power. The final version was powered from the Centronics Port and therefore did not require external power.
The second picture shows NL18’s in production at my home.