"The Cavalry Comes Over the Hill"

I used to hang out at the Pocatello Public Library when I was a kid, because it was an entire building filled with books, and nice people who not only encouraged me to read these books, but also suggested books I might like to read. One day, when I was in the ninth grade (about age fourteen), I met Marty Welch, one of the nice people who had just started working there. Instead of working with all the books, Marty had his own room downstairs, a room filled with equipment of some sort.

( What was that equipment for? )

ETA:
( what others remember )