DS/EN 60821 - IEC 821 VMEBUS - MICROPROCESSOR SYSTEM BUS FOR 1 BYTE TO 4 BYTE DATA Organization: DS Date: 1997-03-12 Description: It is based on the VMEbus specification, released by the VME Manufacturers Group in August of 1982. The bus includes four sub-buses: the Data Transfer Bus, the Priority Interrupt Bus, the Arbitration Bus and the Utility Bus.