"A simpler time"
That's because it wasn't complicated by today's "IP" fanaticism, which treats all computer users like dumb consumers, and prevents them gaining full and unrestricted access to their own legally purchased property, for educational or any other purposes, using both legal and technical measures.
And you expect a manual?
Pfft. Consider yourself lucky that you're even allowed to turn the damned thing on without being given a stiff rectal probing by the "IP" police.
Education is a crime, in the twisted world of "IP" racketeers. No schematics or source code for you, sonny.