Computers that are `never' down [fault-tolerant computers]

Fault-tolerant computers have caught up with the microprocessor revolution. A new approach to fault-tolerant computer design - systems based on multiple microprocessors - is winning followers and challenging the decade-old approach that relies on central processing units (CPUs) made up of medium- and large-scale integrated circuits. Like their predecessors, the multiple microprocessor systems trade throughput for reliability and are proving invaluable in financial transactions, telephony, and a number of other applications that demand high reliability.