The archives still available in 2020 with the software are in pretty bad shape.
Some are even corrupted, others had changes that made the software not
working on COHERENT.
I have fixed everything so that one can build the software again on a
COHERENT 4.0 box. I was careful to not interfere with the porting
for SunOS, Minix and Linux, but I don't know if it can be build on such
platforms from the sources.
So far I only tested with VGA graphics and Microsoft serial mouse,
don't know in which state the sources are for different graphics/mouse
hardware.
I have uploaded a source tarball with my current sources here, in case
someone wants to build boxes from scratch:
https://www.autometer.de/unix4fun/coherent/ftp/new/4.0/
<-> Udo >-<