The VMEbus specification defines an interfacing system used to interconnect microprocessors, data storage, and peripheral control devices in a closely coupled hardware configuration. The system has been conceived with the following objectives:

a) to allow communication between devices on the VMEbus without disturbing the internal activities of other devices interfaced to the VMEbus;

b) to specify the electrical and mechanical system characteristics required to design devices that will reliably and unambiguously communicate with other devices interfaced to the VMEbus;

c) to specify protocols that precisely define the interaction between the VMEbus and devices interfaced to it;

d) to provide terminology and definitions that describe the system protocol;

e) to allow a broad range of design latitude so that the designer can optimize cost and/or performance without affecting system compatibility;

f) to provide a system where performance is primarily device limited, rather than system interface limited.