There entirety of the PC/GEOS operating system, it’s SDK and apparently, ALL of it’s software, have been posted up on Git for community availability and further development !
It appears to be at least PC/GEOS 2.0 and possibly newer. Many files are dated 1991 and many have additional revision dates of “97/04/04 NewDeal” which is at least version 2.5 I believe.
Most of the code is written in C and an updated (??) Watcom C compiler is also available from the author on his Git.
It was common to write GEOS software with “ObjectASM” in i386 assembly. Their object technology was a key advantage they had over other OSes at the time.
You can find the Git repo here:
Here is the Wikipedia page:
…and here is a link to a PDF of the “PC/GEOS System Software Overview”.
This document gives an overview of the system architecture and other details for developers.
The main reason I bring this to the Propeller community is that PC/GEOS could run quite well on an 8088 with 512KB of RAM !! I personally was installing PC/GEOS on these types of PC’s back in the day. One time in particular, I had installed PC/GEOS on an 8MHz 8086 with 640KB RAM and ran it side by side with a 16MHz 286 with 1MB of RAM running Win3.1 and GEOS ran circles around it !! It was ridiculous how much faster GEOS was !!