Defines a framework for 8-, 16-, 32-, and 64-bit parallel bus computer architectures that can implement single and multiprocessor systems. Based on the VMEbus specification released by the VMEbus Manufacturers Group (now VITA) in August 1982, this bus includes the initial four basic subbuses: (1) data transfer bus, (2) priority interrupt bus, (3) arbitration bus, and (4) utility bus. Other architectures with other subbuses are possible within this VME framework.