In Europe, Digital Equipment corporation has introduced a redundant Micro-VAX II configuration, apparently setting its sights on the "fault-tolerant" computer equipment market--those users who never want a computer to go down. (Fault-tolerant refers to the computer, not to the user.) Libraries which want fault-tolerant systems only have had the option of Tandem-based systems from Eyring Research and UTLAS. If Digital brings its new product to the United States and extends the concept to other VAX machines, libraries will have several additional options for mounting patron access catalogs on systems with very high reliability.
The product as introduced in Europe consists of two MicroVAx Its in a single box, each with 5MB of main memory, one 70MB hard disk drive, and a 90MB streaming tape back-up device for just over $110,000. Larger disk storage options are available. Unlike the Tandem approach, the two processors don't work simultaneously on the same operations. Digital has hooked the two VAX IIs together and automatically switches from the primary processor to the secondary processor as needed. The secondary processor is assigned to lower priority tasks until it is needed. The system software provides automatic reconfiguration of the secondary processor. Digital representatives in the U. S. would not comment on the development.