I happen to be in the process of inspecting the fire alarm system of a medium rise building with a Spectronics MX system -- it consists of many MXADM nodes networked to a central panel with MXLC8 display and a DOS-like terminal workstation. The MXADMs control ADS input/output modules and 641/IH-Ps which provides addressable SLC loops using System Sensor CLIP protocol. It's pretty sophisticated and parts of it date back to the 1980s.
What I'm looking for is any sort of documentation. Google turns up nothing. I do know the company that installed it, but since we are already treading on their turf, so to speak, I feel awkward asking them or writing to Spectronics. (They are still in business, not sure at what capacity however!)