Bell 101
Encyclopedia
The Bell 101 dataset or Bell 101 modem was the first commercial modem
for computers, released by AT&T
in 1958 for use by SAGE
and in 1959 made commercial 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 dataset standard.
The Bell 101 modems were the first commercial equipment to use ASCII
, which was called "four row", as opposed to the Baudot
"three row" 6-bit/character code which was predominate from 1908-1962, prior to the rise of EBCDIC.
Modem
A modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...
for computers, released by AT&T
AT&T
AT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...
in 1958 for use by SAGE
Semi Automatic Ground Environment
The Semi-Automatic Ground Environment was an automated control system for tracking and intercepting enemy bomber aircraft used by NORAD from the late 1950s into the 1980s...
and in 1959 made commercial shortly after AT&T's Bell Labs
Bell Labs
Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...
announced their 110 baud modulation frequencies. The Bell 101 modem allowed digital
Digital
A digital system is a data technology that uses discrete values. By contrast, non-digital systems use a continuous range of values to represent information...
data
Data
The term data refers to qualitative or quantitative attributes of a variable or set of variables. Data are typically the results of measurements and can be the basis of graphs, images, or observations of a set of variables. Data are often viewed as the lowest level of abstraction from which...
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
Bell 103 modem
The Bell 103 modem or Bell 103 dataset was the second commercial modem for computers, released by AT&T in 1962. It allowed digital data to be transmitted over regular unconditioned telephone lines at a speed of 300 bits per second. It followed the introduction of the 110 baud Bell 101 dataset in...
. SAGE
Semi Automatic Ground Environment
The Semi-Automatic Ground Environment was an automated control system for tracking and intercepting enemy bomber aircraft used by NORAD from the late 1950s into the 1980s...
modems were described by AT&T's Bell Labs
Bell Labs
Bell Laboratories is the research and development subsidiary of the French-owned Alcatel-Lucent and previously of the American Telephone & Telegraph Company , half-owned through its Western Electric manufacturing subsidiary.Bell Laboratories operates its...
as conforming to the Bell 101 dataset standard.
The Bell 101 modems were the first commercial equipment to use ASCII
ASCII
The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
, which was called "four row", as opposed to the Baudot
Baudot code
The Baudot code, invented by Émile Baudot, is a character set predating EBCDIC and ASCII. It was the predecessor to the International Telegraph Alphabet No 2 , the teleprinter code in use until the advent of ASCII. Each character in the alphabet is represented by a series of bits, sent over a...
"three row" 6-bit/character code which was predominate from 1908-1962, prior to the rise of EBCDIC.