This standard specifies a high-performance backplane bus for use in microcomputer systems that employ single or multiple microprocessors. It is based on the VMEbus specification, released by the VME Manufacturers' Group in August of 1982. The bus includes four subbuses: data transfer bus, priority interrupt bus, arbitration bus, and utility bus. The data transfer bus supports 8-, 16-, and 32-bit transfers over a non-multiplexed 32-bit data and address highway.