Founded in 1990 to supply a US Naval Research Laboratories request for development, FORE initially produced Asynchronous Transfer Mode (ATM) network interface cards for SBus- and TURBOchannel-based computers in addition to Silicon Graphics computers. FORE's first ATM Switch - the ASX-100 - connected 16 ATM ports each with a capacity of 155.52 Mbit/s. Later interface adapters for the follow-on ASX-200, ASX-1000, and ASX-4000 switches allowed connections up to 2.5 Gbit/s.
The company established a leading position in the market for ATM switching equipment. FORE created an advanced memory-based ATM switch that captured a strong portion of the ATM market. Other technologies include Internet Protocol, Gigabit Ethernet and Firewall switching. FORE Systems also supported advanced dynamic routing protocols such as the ForeThought Private Network Network Interface (PNNI) and the ATM Forum's PNNI protocol.
FORE was created by several Carnegie Mellon University professors in a Pittsburgh, Pennsylvania suburb. The name FORE was an acronym of the founders’ first names: Francois Bitz, Onat Menzilcioglu, Robert Sansom, and Eric Cooper.
GEC acquired FORE near the peak of the dot-com bubble. The £2.8bn (US$4.5bn) price tag for FORE Systems (and the £1.3n spent on Reltec a month earlier) took a heavy toll on Marconi following the “burst of the dot-com bubble” in 2000/2001. In July 2001 Marconi plc suffered a 54% drop in its share price following suspension of trading of its shares, a profits warning and redundancies. The company survived following a relaunch as Marconi Corporation plc in a debt-for-equity swap whereby the firm’s creditors received 99.5% of the new company’s shares.
In 2006, Ericsson purchased most of Marconi, including the part that used to be FORE Systems.
Berkeley Networks Inc. Fore Systems Inc. acquired the closely held Berkeley Networks Inc. for $250 million in stock and cash, acquiring equipment that speeds data on computer networks run by Microsoft's Windows NT software. Fore, the No. 7 maker of networking equipment, issued 8.48 million shares for all the shares of Berkeley Net.
Scalable Networks Inc. FORE Systems Inc. acquired Scalable Networks Inc., an O'Hara Township, Pennsylvania developer of high-performance technology used to access asynchronous transfer mode (ATM) networks for about $34 million. The deal adds a line of local area network (LAN) equipment to FORE's product line and is likely to enhance the company's position in the global ATM market.
Alantec Inc. FORE Systems Inc. acquired Alantec Inc. for about $768 million. Alantec, a San Jose, California manufacturer of Ethernet and FDDI switching hubs, provided IEEE 802 Ethernet to ATM aggregation.