Bell 101
(Redirected from Bell 101 modem)
The Bell 101 Data Set was the first commercial modem for computers, released by AT&T Corporation in September 25, 1958 for use by SAGE, and made commercially available in 1959, shortly after AT&T's Bell Labs announced their 110 baud modulation frequencies.[1][2] The Bell 101 allowed digital data to be transmitted over regular unconditioned telephone lines at a speed of 110 bits per second.
The Bell 101 modem used audio frequency-shift keying to encode data. Different pairs of audio frequencies were used by each station:[3]
- The originating station used a mark tone of 1,270 Hz and a space tone of 1,070 Hz.
- The answering station used a mark tone of 2,225 Hz and a space tone of 2,025 Hz.
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
[edit | edit source]References
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Further reading
[edit | edit source]- Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
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- Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
