Cosma / Communication / Media / Communications / Hardware / Modem

If you need to swap faxes, relax.
Most computers have modems that fax.
They don’t cost very much
And can add a nice touch
For both Windows computers and Macs. —
Skip Jordan, fax modem, OEDILF




modem : a device that converts signals produced by one type of device (such as a computer) to a form compatible with another (such as a telephone) and that is used especially to transmit and receive information between computers via landlines — Webster   See also OneLook

Modem (FOLDOC: Free Online Dictionary of Computing)


Modem (portmanteau of modulator-demodulator) is a hardware device that converts data into a format suitable for a transmission medium so that it can be transmitted from computer to computer (historically over telephone wires). A modem modulates one or more carrier wave signals to encode digital information for transmission and demodulates signals to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded reliably to reproduce the original digital data. Modems can be used with almost any means of transmitting analog signals from light-emitting diodes to radio. A common type of modem is one that turns the digital data of a computer into modulated electrical signal for transmission over telephone lines and demodulated by another modem at the receiver side to recover the digital data.

Modems are generally classified by the maximum amount of data they can send in a given unit of time, usually expressed in bits per second (symbol bit(s), sometimes abbreviated “bps”) or rarely in bytes per second (symbol B(s)). Modems can also be classified by their symbol rate, measured in baud. The baud unit denotes symbols per second, or the number of times per second the modem sends a new signal. For example, the ITU V.21 standard used audio frequency-shift keying with two possible frequencies, corresponding to two distinct symbols (or one bit per symbol), to carry 300 bits per second using 300 baud. By contrast, the original ITU V.22 standard, which could transmit and receive four distinct symbols (two bits per symbol), transmitted 1,200 bits by sending 600 symbols per second (600 baud) using phase-shift keying. — Wikipedia

Modem (Encyclopædia Britannica)


Modem (WolframAlpha)




The bases of the digital computers, Modem (History of Computers and Computing)
History of Modems (Wikipedia)


WorldCat, Library of Congress, UPenn Online Books, Open Library




MERLOT: Multimedia Educational Resource for Learning and Online Teaching
OER Commons: Open Educational Resources


NPR Archives









OEDILF: The Omnificent English Dictionary In Limerick Form




Here are links to pages about closely related subjects.


Function Communications Computation Storage Creation Simulation
Analog Mail Device Paper Type, Print Automaton
Electronic Network Calculator Tape Record Elektro
Digital Internet Computer
Hardware Modem Microprocessor Memory Peripheral Robot, XR
Software Service (Web) Program (OS, SS) Database Application AI, VW

Format Multimedia (Video, Animation) Image (Object) Scent, Flavor, Audio (Text) Haptic, “Other



1.   The resources on this page are are organized by a classification scheme developed exclusively for Cosma.