ASR-33 with Bell 101 Modem


Who Teletype Corporation
What ASR-33
When 1959 / 1963
Why 1960s terminal with interesting options

An ASR-33 Teletype with external answerback unit and Bell 101C modem.

The answerback unit electro-mechanically transmits 20 bytes encoded on a plastic drum. The ASR-33 has this functionality builtin, so this is a rare combination. It was more often found with earlier Teletype models.

The Bell 101 modem was introduced in 1958 for the SAGE defense system. In 1959 it was offered to the public, becoming the very first commercially available modem.

The modem functionality is split across seven boards:

There's a lot of wire wrap & relays:

An example of one of the boards: