Dialup UK Article - The Evolution Of Dialup Modems
A modem is typically a device used to transmit data over
a phone line ina dialup internet connection. The word "modem"
is a retrenchment of the words modulator-demodulator. Its
main function is to transmit data to both the sides (computer
and phone line) in the form compatible to the concerned side.
The sending modem modulates the data into analog signal that
is compatible with the phone line, and the receiving modem
demodulates the signal back into digital data compatible to
Modems came into existence in the 1960s. The early modems
were exclusively used to allow dumb terminals to connect to
computers over the phone lines. That was the age of time-shared
computers. Hence, a business could buy computer time from
a time-share facility and connect to it via modem. These early
modem could transmit data at a speed of 300 bits per second.
In systems existed at that time, a dumb terminal consisted
simply a keyboard and a monitor. The most commonly used dumb
terminals could display 25 lines at a time and 80 characters
in each line on the monitor screen. When the user typed a
character on keyboard of the dumb terminal, the modem sent
the ASCII code for the character to the central computer.
The central computer then sent the character back to the computer
so it would appear on the screen. This mode of data transfer
was extensively used to enable dumb terminal at a remote site
to dial in to a large, central computer.
The use of the modems was further extended to home uses in
1970’s when personal computers started appearing. With
the modem technology available at that time, bulletin board
systems (BBS) became highly popular. A user could set up a
computer with a modem and BBS software and other people would
dial in to connect to the bulletin board. The users would
run terminal emulators on their computers to emulate a dumb
terminal. The bulletin boards became a popular source of sharing
information. The era of the 300 bps modems went on in this
time of character-based computers. The reason is that the
speed was sufficient to run the character based data transfers
as the modem could transfer about 30 characters per second.
This is a lot more characters per second than a person can
type or read.
The evolution of the modems went further with the introduction
of Internet and dial up Internet access in 1980’s. The
300 bps modems went out of use once the once GUI (graphical
user interface) was introduced. With advancement of internet,
people started transferring larger programs and images over
the Internet though next generation modems that were capable
of transferring data at 900 to 1200 bps. As the data transfer
over the Internet increased rapidly in 1990’s, modems
also improved on their speeds. Modems that could transfer
data from 9600 bps to 33.6 Kbps came into use and gone. The
most used modem in the mid 1990’s was the 33.6 Kbps
modems. The final step in the evolution came in 1998, when
56Kbps modems become standard. The 56kbps modems are now most
widely used modems in the world.