The Bell 212A modulation scheme defined a standard method of transmitting
full-duplex asynchronous
Asynchrony is the state of not being in synchronization.
Asynchrony or asynchronous may refer to:
Electronics and computing
* Asynchrony (computer programming), the occurrence of events independent of the main program flow, and ways to deal with ...
serial data at 1.2 kbit/s over analogue transmission lines. The equivalent, but incompatible
ITU-T standard is
V.22.
Device
The Bell 212 Dataset is a 1979-vintage
modem used for communicating over telephone lines at 300 or 1200 bits per second.
The 212A standard provides for the ability of a modem to auto-answer a ringing phone.
[
]
Usage
The Bell 212A scheme was the most common standard used for 1200 bps transmission on US data networks such as CompuServe
CompuServe (CompuServe Information Service, also known by its initialism CIS) was an American online service provider, the first major commercial one in the world – described in 1994 as "the oldest of the Big Three information services (the oth ...
during the period that dial-up Internet access
Dial-up Internet access is a form of Internet access that uses the facilities of the public switched telephone network (PSTN) to establish a connection to an Internet service provider (ISP) by dialing a telephone number on a conventional telepho ...
was the norm (1980s and 1990s).[Frank J. Derfler Jr.]
"Selecting the right modem"
''PC Magazine'', pp. 224-233, January 1983.[Frank J. Derfler]
"The Universal Data Systems' 212 LP modem"
''InfoWorld'', pp. 52-53, 9 August 1982.
See also
*List of device bandwidths
This is a list of interface bit rates, is a measure of information transfer rates, or digital bandwidth capacity, at which digital interfaces in a computer or network can communicate over various kinds of buses and channels. The distinction can ...
References
Data transmission
{{Telecomm-stub
Telecommunications-related introductions in 1979