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Teleprinters, one of the last gasps of the pre-computer digital network, took a long time to die.
Although they were limited in speed and scope — basically, electric typewriters that could talk to each other at around 10 characters a second — messages passed on the public Telex teleprinter network were legally considered to have their source and destination verified. This kept the network going as an important business tool long past the point where it was technologically obsolete.
Teleprinters live on in virtual form in shortwave radio, where radioteletype — RTTY — is still used by radio amateurs, for no particularly good reason.
Image credit: BT