My feeling was that Andrew and SPICE were completely separate workstation projects at CMU, but only from using the software that came out of each of them.
Not completely, but it wasn't a huge place, and the communities overlapped, went to some of the same seminars, etc. It was all in Wean, pretty much clustered by floor. Andrew was very much about distributed computing ala Athena; SPICE was more along workstation lines (and what was then called AI). As I recall, internet access (IMP, when /etc/hosts was exhaustive) was only the Vaxen and maybe some TOPS systems.
I had access to a PERQ in about 1985, and it was running Pascal firmware - at the time, Pascal was the baseline language for CS courses. I seem to recall it had a tiling WM and a mouse about the size of a softball. There were Altos upstairs though I think they only acted as queues for the building's laser printers (which implemented some pre-PS page description language). But those were the days when 9600 baud was the norm...
They were; their main point of connection was at the OS level, as Accent on PERQ begat Mach, and Andrew originally ran atop CMU’s Mach+BSD environment (MK+UX). That let it take advantage of features such as Mach IPC and dynamic loading of shared libraries and plug-in modules. Later Andrew was ported to vendor operating systems, and then to run atop X11 instead of wm.
