In the

computer hacking A hacker is a person skilled in information technology who uses their technical knowledge to achieve a goal or overcome an obstacle, within a computerized system by non-standard means. Though the term ''hacker'' has become associated in popu ...

scene of the 1980s, demon dialing was a technique by which a computer was used to repeatedly dial a number (usually to a crowded

modem A modulator-demodulator or modem is a computer hardware device that converts data from a digital format into a format suitable for an analog transmission medium such as telephone or radio. A modem transmits data by modulating one or more c ...

pool) in an attempt to gain access immediately after another user had hung up. The expansion of accessible

internet service provider An Internet service provider (ISP) is an organization that provides services for accessing, using, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, non-profit, or otherwise privatel ...

connectivity since that time has rendered the practice more or less obsolete. A similar technique was sometimes used to get the first call for prizes in radio "call-in" shows, thus leading to the adoption of random "fifth caller," "seventeenth caller" etc. by radio stations to circumvent this practice. The term "demon dialing" derives from the Demon Dialer product from

Zoom Telephonics Minim, Inc., formerly Zoom Telephonics, is an American networking company that develops software and designs hardware for Internet security. Headquartered in Manchester, New Hampshire, the company offers a mobile app, cable modems, gateways, WiFi ...

, Inc., a telephone device produced in the 1980s which repeatedly dialed busy telephone numbers under control of an extension phone. The emergence of affordable consumer telephony devices with advanced features such as last number redial and preprogrammed numbers paralleled phone industry deregulation and the

Breakup of the Bell System The breakup of the Bell System was mandated on January 8, 1982, by an agreed consent decree providing that AT&T Corporation would, as had been initially proposed by AT&T, relinquish control of the Bell Operating Companies, which had provided lo ...

in the early 1980s. While

Speed dial Speed dial is a function available on many telephone systems allowing the user to place a call by pressing a reduced number of keys. This function is particularly useful for phone users who dial certain numbers on a regular basis. In most case ...

technology had been invented nearly a decade earlier by Bell Labs, it did not become a consumer product until deregulation. Previously, connecting non-AT&T handsets was generally prohibited and most phones were leased devices (similar to residential broadband routers). By putting its functionally in a line-connected appliance rather than a handset, the Demon Dialer device could be configured to provide speed dialing to all extensions within a residence through touch tone control. "Demon dialing" was popularized by the movie ''

WarGames ''WarGames'' is a 1983 American science fiction techno-thriller film written by Lawrence Lasker and Walter F. Parkes and directed by John Badham. The film, which stars Matthew Broderick, Dabney Coleman, John Wood, and Ally Sheedy, foll ...

'', which demonstrates the hacking technique (the technique eventually evolves into a technique called "phreaking"). After giving the program an area code and 3 digit prefix, the program then serially dialed every phone number in that prefix in order, recording which phone numbers were answered by a computer modem. Soon after, most likely because it was popularized by the movie, serial dialing was outlawed. Hackers got around this by simply randomizing the order the program dialed all the numbers. Later the terms "demon dialing" and "

war dialing Wardialing (or war dialing) is a technique to automatically scan a list of telephone numbers, usually dialing every number in a local area code to search for modems, computers, bulletin board systems ( computer servers) and fax machines. Hacke ...

" became synonymous.

Similar technologies

Automatic redial In telecommunication, an automatic redial is a service feature that allows the user to dial, by depressing a single key or a few keys, the most recent telephone number dialed at that instrument. ''Note:'' Automatic redial is often associated w ...

is essentially exactly the same thing, but for modems, and included in most telecommunications programs that use modems, including all variants of

Dial-up networking 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 ...

ever included in the

Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for ...

operating system.

References

{{reflist Telephony