How to Use a Mod 26 Keypunch
Purdue University had a dwindling number of publicly accessible card punch machines into the mid 1980s. The legends said that one or two were kept running for several more years, to support old projects, run by old professors, who every so often somehow needed to run their card stack one more time.
A 6-page manual was available for users. Behold:
For more computer ancient history,
here's is IBM's 49-page manual for their model 29 card punch.
Reference Manual: IBM 29 Card Punch