Teletypewriter is a synonym of teleprinter.

Teleprinter is a see also of teletypewriter.

As nouns the difference between teleprinter and teletypewriter

is that teleprinter is (dated) a combined electromechanical typewriter and printer, often with an integrated paper tape reader/printer, connected to others or to a computer via the telephone system while teletypewriter is an electromechanical communications device consisting of a typewriter keyboard and printer together with a punched paper tape reader/writer and connection to a modem so that information may be sent and received over a telephone system.