The IBM PC Network was

IBM International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...

PC's first LAN system. It consisted of

network card A network interface controller (NIC, also known as a network interface card, network adapter, LAN adapter and physical network interface) is a computer hardware component that connects a computer to a computer network. Early network interface ...

s, cables, and a small

device driver In the context of an operating system, a device driver is a computer program that operates or controls a particular type of device that is attached to a computer or automaton. A driver provides a software interface to hardware devices, enabli ...

known as

NetBIOS NetBIOS () is an acronym for Network Basic Input/Output System. It provides services related to the session layer of the OSI model allowing applications on separate computers to communicate over a local area network. As strictly an API, Net ...

(Network Basic Input/Output System). It used a data rate of and carrier-sense multiple access with collision detection.

was developed by Sytek Inc as an API for software communication over this IBM PC Network LAN technology; with Sytek networking protocols being used for communication over the wire. IBM's later

Token Ring Token Ring is a Physical layer, physical and data link layer computer networking technology used to build local area networks. It was introduced by IBM in 1984, and standardized in 1989 as IEEE Standards Association, IEEE 802.5. It uses a sp ...

network emulated the NetBIOS

application programming interface An application programming interface (API) is a connection between computers or between computer programs. It is a type of software Interface (computing), interface, offering a service to other pieces of software. A document or standard that des ...

, and it lived on in many later systems.

Broadband

The original

broadband In telecommunications, broadband or high speed is the wide-bandwidth (signal processing), bandwidth data transmission that exploits signals at a wide spread of frequencies or several different simultaneous frequencies, and is used in fast Inter ...

version in 1984 communicated over 75 Ω

cable television Cable television is a system of delivering television programming to consumers via radio frequency (RF) signals transmitted through coaxial cables, or in more recent systems, light pulses through fibre-optic cables. This contrasts with bro ...

compatible co-axial cable with each card connecting via a single

F connector F, or f, is the sixth letter of the Latin alphabet and many modern alphabets influenced by it, including the modern English alphabet and the alphabets of all other modern western European languages. Its name in English is ''ef'' (pronounc ...

. Separate transmit and receive frequencies were used. Cards could be ordered that used different frequencies so multiple cards could transmit simultaneously, at each. A Sytek head-end device was required to translate from each card's transmit frequency to the destination card's receive frequency.

Frequency-division multiplexing In telecommunications, frequency-division multiplexing (FDM) is a technique by which the total bandwidth (signal processing), bandwidth available in a communication channel, communication medium is divided into a series of non-overlapping freque ...

allowed the cable to be shared with other voice, video, and data traffic.

Baseband

Later, in 1987 a much cheaper

baseband In telecommunications and signal processing, baseband is the range of frequencies occupied by a signal that has not been modulated to higher frequencies. Baseband signals typically originate from transducers, converting some other variable into ...

version, also running at connected computers in daisy-chain style using twisted-pair cables with

6P2C A modular connector is a type of electrical connector for cords and cables of electronic devices and appliances, such as in computer networking, telecommunication equipment, and audio headsets. Modular connectors were originally developed for ...

modular telephone connectors. Interface cards had two 6P2C sockets for connecting to left and right neighbor nodes. The unused sockets at the ends of the network segment had to be fitted with a terminator on one end of the chain and a wrap plug on the other. A hybrid star topology was possible using a hub.

References

Local area networks PC Network {{Computer-stub

Broadband

Baseband

See also

References