Short for MODulator/DEModulator, the first Modem known as the Dataphone, which was first released by AT&T in 1960. It later became more common for home users when Dennis Hayes and Dale Heatherington released the 80-103A Modem in 1977.The Modem is a hardware device that enables a computer to send and receive information over telephone lines by converting the digital data used by your computer into an analog signal used on phone lines and then converting it back once received on the other end. In the picture below, is an example of an internal expansion card modem.
Modems are referred to as an asynchronous device, meaning that the device transmits data in an intermittent stream of small packets. Once received, the receiving system then takes the data in the packets and reassembles it into a form the computer can use.
Types of Computer Modems
Below are the four versions of a computer Modem found in computers:
Onboard Modem is a Modem that is built onto the computer motherboard. These Modems cannot be removed, but can be disabled through a Jumper or CMOS Setup.
Internal Modem connects to a PCI slot inside a newer desktop computer or ISA slot on an older computer. The Internal Modem shown at the beginning of this document is an example of a PCI modem.
External Modem is located within a box and is hooked up externally to the computer, usually the Serial Ports or USB port. The picture is an example of
an externalUSRobotics Modem.
Removable Modem that is used with olderlaptops PCMCIA slot and is removed when you need the PCMCIA slot for another device, but are not planning on using the modem.
A Modem or Broadband Modem is also used to refer to the hardware device that connects a computer or router to a broadband network. For example, a Cable Modem and DSL Modem are two examples of these types of Modems.
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