Tandem Computers

Tandem Computers, Inc. was the dominant manufacturer of fault-tolerant computer systems for ATM networks, banks, regulated international markets, telephone switching centers, emergency telephone number systems and other transaction processing applications that need maximum uptime and no data loss. Jimmy Treybig, who had run marketing for the HP 3000 division of Hewlett-Packard, founded the company in 1974 in Cupertino, California, with Mike Green, James Katzman and Jack Loustaunou, after Hewlett-Packard declined to develop for this niche. Its NonStop systems use several independent identical processors, redundant storage and redundant controllers that share nothing, not even main memory, and cooperate by exchanging messages, so a hardware or software failure triggers automatic failover and capacity scales with the number of processors. In 2002 about 95 percent of worldwide stock transactions and two thirds of credit card transactions were handled by NonStop computers. The first release of its T/16 had a single programming language, Transaction Application Language. Tandem remained independent until 1997, when it became a server division within Compaq, and it is now a server division within Hewlett Packard Enterprise.