VMEbus

related topics
{system, computer, user}
{work, book, publish}
{government, party, election}
{law, state, case}
{math, number, function}
{group, member, jewish}
{theory, work, human}

VMEbus is a computer bus standard, originally developed for the Motorola 68000 line of CPUs, but later widely used for many applications and standardized by the IEC as ANSI/IEEE 1014-1987. It is physically based on Eurocard sizes, mechanicals and connectors (DIN 41612), but uses its own signalling system, which Eurocard does not define. It was first developed in 1981 and continues to see widespread use today.

Contents

History

In 1979, Motorola was developing their new Motorola 68000 CPU and one of their engineers, Jack Kister, decided to set about creating a standardized bus system for 68000-based systems. The Motorola team brainstormed for days to select the name VERSAbus. Kister was later joined by John Black, who refined the specifications and created the VERSAmodule product concept. A young engineer working for Black, Julie Keahey designed the first VERSAmodule card the VERSAbus Adaptor Module used to run existing cards on the new VERSAbus. Sven Rau and Max Loesel of Motorola-Europe added a mechanical specification to the system, basing it on the Eurocard standard that was then late in the standardization process. The result was first known as VERSAbus-E but was later renamed to VMEbus, for VERSAmodule Eurocard bus (although some refer to it as Versa Module Europa). [1]

At this point, a number of other companies involved in the 68000's ecosystem agreed to use the standard, including Signetics, Philips, Thomson, and Mostek. Soon it was officially standardized by the IEC as the IEC 821 VMEbus and by ANSI and IEEE as ANSI/IEEE 1014-1987.

The original standard was a 16-bit bus, designed to fit within the existing Eurocard DIN connectors. However there have been several updates to the system to allow wider bus widths. The current VME64 includes a full 64-bit bus in 6U-sized cards and 32-bit in 3U cards. The VME64 protocol has a typical performance of 40 MB/s. Other associated standards have added hot-swapping (plug-and-play) in VME64x, smaller 'IP' cards that plug into a single VMEbus card, and various interconnect standards for linking VME systems together.

Full article ▸

related documents
Aster CT-80
Sinclair ZX Spectrum
Radioteletype
Commodore VIC-20
Debian
SCSI
Supercomputer
WordStar
FidoNet
Intel 8080
Super Audio CD
Programmable logic controller
Wavelength-division multiplexing
Modulation
ARM architecture
PDP-10
IBM POWER
Athlon
Atari 2600
Mac OS X
Audio crossover
History of operating systems
Direct memory access
Remote control
QuickTime
Iridium (satellite)
Audiophile
GIMP
Dynamic Host Configuration Protocol
Bus (computing)