They allowed users to interact directly with an IBM Mainframe using only a touch-tone telephone or a terminal which could generate tones.

They are notable for being part of a number of first of a kind IT solutions and also for enabling what is described as the "world's first talking computer".

The drum is designed to be interchanged if required, allowing the user to change the vocabulary.

The vocabulary was stored in a random access disk device in a digitally coded form.

[6] The 7772 is mentioned in online documents as early as 1964[6] and is listed as withdrawn in the 1979 IBM Sales Manual.

[19] The IBM 1001 Data Transmission terminal allows a user to dial into an Audio Response Unit and send characters entered either with a 10 digit keyboard or from the first 22 columns of a punched card.