> ENQ (Enquiry), ACK (Acknowledge) In the days of hardware serial terminals, there was a convention that if a computer sent ENQ to a terminal, it should reply w

> ENQ (Enquiry), ACK (Acknowledge) In the days of hardware serial terminals, there was a convention that if a computer sent ENQ to a terminal, it should reply with terminal type identification followed by ACK. While this was not universal, it at least gave computers a fighting chance of autoconfiguring what capabilities it could assume the character to have. That's not quite right (the ACK part isn't right at all). See <https://en.wikipedia.org/wiki/Enquiry_character> https://en.wikipedia.org/wiki/Enquiry_character>.