IPSANET was a packet switching

Packet switching

Packet switching is a digital networking communications method that groups all transmitted data – regardless of content, type, or structure – into suitably sized blocks, called packets. Packet switching features delivery of variable-bit-rate data streams over a shared network...

 network

Computer network

A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....

 written by I. P. Sharp Associates

I. P. Sharp Associates

I. P. Sharp Associates, IPSA for short, was a major Canadian computer time sharing, consulting and services firm of the 1970s and 80s. IPSA is particularly well known for its work on the APL programming language, an early packet switching computer network known as IPSANET, and a powerful...

 (IPSA). Operation began in May 1976. It initially used IBM 3705

IBM 3705 Communications Controller

The IBM 3705 Communications Controller was a simple computer which attached to a IBM System/360 or System/370. Its purpose was to connect communication lines to the mainframe channel. It was a first communications controller of the popular IBM 37xx series. It was announced in March 1972...

s and Computer Automation

Computer Automation

Computer Automation Inc. was a computer manufacturer founded by David H Methvin in 1968, based originally in Irvine, California, USA.In 1981 they moved to Boulder, Colorado, and in 1985 moved back to Irvine, California...

 LSI-2 computers as node

Node (networking)

In communication networks, a node is a connection point, either a redistribution point or a communication endpoint . The definition of a node depends on the network and protocol layer referred to...

s. An Intel 80286

Intel 80286

The Intel 80286 , introduced on 1 February 1982, was a 16-bit x86 microprocessor with 134,000 transistors. Like its contemporary simpler cousin, the 80186, it could correctly execute most software written for the earlier Intel 8086 and 8088...

 based-node was added in 1987. It was called the Beta node.

The original purpose was to connect low-speed dumb terminals to a central time sharing host in Toronto. It was soon modified to allow a terminal to connect to an alternate host running the SHARP APL software under license. Terminals were initially either 2741

IBM 2741

The IBM 2741 was a printing computer terminal introduced in 1965.It combined a ruggedized Selectric typewriter mechanism with IBM SLT electronics and an RS-232-C serial interface. It operated at about 14.1 characters per second with a data rate of 134.5 bits/second...

-type machines based on the 14.8 characters/s IBM Selectric typewriter

IBM Selectric typewriter

The IBM Selectric typewriter was a highly successful model line of electric typewriters introduced by IBM on July 31, 1961.Instead of the "basket" of individual typebars that swung up to strike the ribbon and page in a traditional typewriter, the Selectric had a type element that rotated and...

 or 30 character/s ASCII machines. Link speed was limited to 9600 bit/s until about 1984.

Other services including 2780/3780 Bisync

Binary Synchronous Communications

Binary Synchronous Communication is an IBM link protocol, announced in 1967 after the introduction of System/360. It replaced the synchronous-transmit-receive protocol used with second generation computers. The intent was that common link management rules could be used with three different...

 support, remote printing, X.25

X.25

X.25 is an ITU-T standard protocol suite for packet switched wide area network communication. An X.25 WAN consists of packet-switching exchange nodes as the networking hardware, and leased lines, Plain old telephone service connections or ISDN connections as physical links...

 gateway and SDLC

Synchronous Data Link Control

Synchronous Data Link Control is a computer communications protocol. It is the layer 2 protocol for IBM's Systems Network Architecture . SDLC supports multipoint links as well as error correction. It also runs under the assumption that an SNA header is present after the SDLC header...

 pipe lines were added in the 1978 to 1984 era. There was no general purpose data transport facility until the introduction of Network Shared Variable Processor (NSVP) in 1984. This allowed APL programs running on different hosts to communicate via Shared Variables.

The Beta node improved performance and provided new services not tied to APL. An X.25

X.25

X.25 is an ITU-T standard protocol suite for packet switched wide area network communication. An X.25 WAN consists of packet-switching exchange nodes as the networking hardware, and leased lines, Plain old telephone service connections or ISDN connections as physical links...

 interface was the most important of these. It allowed connection to a host which was not running SHARP APL.

IPSANET allowed for the development of an early yet advanced e-mail

E-mail

Electronic mail, commonly known as email or e-mail, is a method of exchanging digital messages from an author to one or more recipients. Modern email operates across the Internet or other computer networks. Some early email systems required that the author and the recipient both be online at the...

service, 666 BOX, which also became a major product for some time, originally hosted on IPSA's system, and later sold to end users to run on their own machines. NSVP allowed these remote e-mail systems to exchange traffic.

The network reached its maximum size of about 300 nodes before it was shut down in 1993.