Definition: Tandem

Tandem Computers was a major manufacturer of fault-tolerant computers founded in 1974 by James Treybig. It was the first company to address the transaction processing (OLTP) market for online reservations and financial transfers. Tandem computers were designed from the ground up for fault-tolerant operation in banks, stock exchanges, credit card companies and ATM machines. The company's most significant product was its MIPS-based Himalaya series that ran Tandem's Guardian OS and NonStop kernel.

In 1997, Compaq Computer acquired Tandem, and HP bought Compaq in 2002. After HP split into two companies, the Tandem technology lives on in the NonStop servers from HP Enterprise (HPE). See ServerNet and HP Enterprise.

James Treybig

Treybig founded Tandem and was at its helm for more than 20 years. (Image courtesy of Tandem Computers Incorporated.)

NonStop Processing

Tandem was the first company to build fault-tolerant systems for the OLTP market. At the top is Tandem's first NonStop system in 1976. At the bottom is the K10000, a massively parallel server that can scale up to 4,000 processors. See MPP. (Images courtesy of Tandem Computers Incorporated.)