Imagesource: Zilog, Inc.

Another piece of quite intriguing history emerged this week from the Z80 realm.

Did you know that Zilog, in the late 70s, developed not only CP/M but also another operating system called Z80-RIO for its in-house machines? And they did so quite seriously, complete with relocatable modules and I/O management and stuff... 😯

No? Neither did we!

However, writer Maya Posch aka @MayaPosch thankfully enlightened us recently, drawing attention to the preservation efforts of Ralf-Peter Nerlich aka @Zweieck2.

This dedicated individual is on a mission to preserve and gather as much information on RIO and PLZ, reflecting on his personal experiences working with them when they were brand new.

Although these machines and the OS itself faded into obscurity by the early 80s, the versatility of the expandable hardware paired with the CP/M alternative is quite remarkable for its time when viewed from a modern perspective.

Curious? Relevant reading material can be found in the form of the corresponding hackaday.com article here.