Today we know of Micromat as the company that sells the TechTool Pro disk diagnostic and repair utility. What a few of us old-timers remember is that when Micromat started up in 1989, they were primarily a Mac repair shop that also sold kits of parts to hobbyists who were not afraid to delve into the guts of their machines on their own. When the analog board of our first hand-me-down Mac went bad, it was Micromat's little baggie of parts (and the instructions where they went) to the rescue!
Micromat's early parts catalogs were HyperCard stacks distributed on 3.5-inch floppy disks.
I found this old installation guide while I was out in the shed gathering tools and materials for a garden project.