X circa 1992

[Geruva Publications]

Gentlemen,

I am looking at the adaptation of a fairly sizable software package to a 
more modern (Linux) environment. The package in it's present state is 
configured to use X for graphics, but it appears to date from about 1992.

In some of the release notes, it is stated that for the system will only 
work with "variants 31 - 39". Troubling, but I have no idea what this 
means, but one of you might. In any event, I would like to have some 
idea about what would be needed to move to contemporary X11. If you 
could provide some kind of guidance or starting point for my inquiry, I 
would be most appreciative.

Sincerely,

Arnold Kochman