Tandem Computers

Tandem Computers was an early manufacturer of fault tolerant computer systems, marketed to the growing number of transaction processing customers who used them for ATMs, banks, stock exchanges and other similar needs. Tandem systems used a number of redundant processors and storage devices to provide high-speed "failover" in the case of a hardware failure, an architecture that they called NonStop. Over the two decades from the 1970s into the mid-90s, Tandem systems evolved from custom hardware to commodity CPU designs. The company was eventually purchased by Compaq in 1997 in order to provide that company with more robust server offerings. Today it is still known as NonStop, as a separate product line offered by Hewlett-Packard, ironically the company that the original founders left to form Tandem in the first place.