Bell 101 modem
The Bell 101 modem, or Bell 101 Data Set, was the first commercial modem for computers, released by AT&T Corporation in 1958 for use by SAGE and in 1959 made commercially available shortly after AT&T's Bell Labs announced their 110 baud modulation frequencies. The Bell 101 modem allowed digital data to be transmitted over regular unconditioned telephone lines at a speed of 110 bits per second. Bell 101 modems are no longer in use and were quickly replaced by its successor the Bell 103 modem. SAGE modems were described by AT&T's Bell Labs as conforming to the Bell 101 data set standard. See also
 List of device bandwidths
 Bell 202 modem

References

Further reading
 
 
 
 

Modems
AT&T
Computer-related introductions in 1959
Telecommunications-related introductions in 1959