I worked for a company called Telexpress. They has a terminal
emulater called Teleterm. The program was table driven, and
allowed you to create new terminal definitions.

A customer might buy a canned system from a vertical market
vendor that included a server (Unix, Pick, Vax, etc) and some
terminals. The terminal could be ANYTHING. In those
days, new ones were popping up all the time. They would want
to hook up their PCs (days of original PC and XT) to the
system.

So they would send us a terminal and the manual. I would
review the manual and create a termcap entry for the terminal
if it did not exist. I would then reverse that and create
the table entries that our software would use to create a
new terminal.

Was a great education. I owe them a lot for it.