An 8-tube module from a 1954 IBM mainframe examined: it's a key debouncer http://www.righto.com/2018/01/examining-1954-ibm-mainframes-pluggable.html
Still learning the Vim vocabulary. How to search for a particular word: To find the word duck, use :/duck. Then type n for the next occurrence. If you are already in your text on the word "duck," type # or ? in command mode to find the next occurrence.