In 1981 the VMEbus architecture was created. The new design combined the VERSAbus electrical specification, which was based on microprocessor technology, with the rugged and modular Eurocard packaging system. Both were proven, off-the-shelf technologies. The resulting combination was successful because it solved the durability problem and could be easily adapted to a wide variety of applications.
The original planners had the foresight to place the VMEbus specification into the public domain. This not only meant that everybody had to conform to the same technical standard, it also meant that they had to compete directly on the basis of price, performance, quality and time-to-market. It was a buyers market that meant lower margins for the suppliers, but also lower costs for the consumer The adoption of VMEbus as a public domain standard was a shrewd political move because it was easier to accept by a group of competitors. The new market also had low barriers to entry which meant that third parties could enter the marketplace with less difficulty.
From the forward of ANSI/IEEE Std 1014-1987 and ANSI/VITA 1-1994
The architectural concepts of the VMEbus are based on the VERSAbus, developed in the late 1970’s by Motorola. Motorola’s European Microsystems group in Munich, West Germany proposed the development of a VERSAbus-like product line based on the Eurocard mechanical standard. To demonstrate the concept, Max Loesel and Sven Rau developed three prototype boards: (1) a 68000 CPU board, (2) a dynamic memory board, and (3) a static memory board. They named the new bus VERSAbus-E, which was later renamed “VME” by Lyman (Lym) Hevle, then VP with the Motorola Microsystems Operation (and later the founder of the VME Marketing Group which was renamed VME International Trade Association (VITA)). VME is the acronym for VERSA-module Europe. Motorola, Mostek, and Signetics agreed to jointly develop and support the new bus architecture in early 1981. These companies were all early supporters of the 68000 microprocessor family.
John Black of Motorola, Craig McKenna of Mostek, and Cecil Kaplinsky of Signetics developed the first draft of the VMEbus specification. In October of 1981, at the System ’81 trade show in Munich, West Germany, Motorola, Mostek, Signetics/Phillips, and Thomson CSF announced their joint support of the VMEbus, and placed Revision A of the specification in the public domain. In August of 1982, Revision B of the VMEbus specification was published by the newly formed VMEbus Manufacturers’ Group (now VITA). This new revision refined the electrical specifications for the signal line drivers and receivers, and also brought the mechanical specification more in line with the developing IEC 297 standard, the formal specification for Eurocard mechanical formats. In the later part of 1982, the French delegation of the International Electrotechnical Commission (IEC) proposed Revision B of the VMEbus as an international standard. The IEC SC47B subcommittee nominated Mira Pauker of Phillips, France, as the chairperson of an editorial committee, formally starting international standardization of the VMEbus.
In March of 1983, the IEEE Microprocessor Standards Committee (MSC) requested authorization to establish a working group to standardize the VMEbus in the US. This request was approved by the IEEE Standards Board, and the P1014 Working Group was established. Wayne Fischer was appointed first chairman of the working group. John Black served as chairman of the P1014 Technical Subcommittee. The IEC, IEEE and VMEbus Manufacturers Group (now VITA) distributed copies of Revision B for comment, and received requests for changes to the document as a result. These comments made it clear that it was time to go forward past Revision B. In December of 1983, a meeting was held that included John Black, Mira Pauker, Wayne Fischer, and Craig McKenna. It was agreed that a Revision C should be created, and that it should take into consideration all the comments received by the three organizations. John Black and Shlomo Pri-Tal of Motorola incorporated the changes from all sources into a common document. The VMEbus Manufacturers Group labeled the document Revision C.1 and placed it in the public domain. The IEEE labeled it P1014 Draft 1.2, and the IEC labeled it IEC 821 Bus. Subsequent ballots in the IEEE P1014 Working Group and in the MSC resulted in more comments, and required that the IEEE P1014 draft be updated. This work resulted in ANSI/IEEE 1014-1987 specification.
The process that led to the development of ANSI/IEEE Std 1014 embodies the philosophy that the “.IEEE will cooperate with standardizing groups throughout the world in the preparation of standards.” as expressed in the IEEE Standards Manual. The development of the VMEbus was a team effort, which involved experts from the United States, Britain, West Germany, France, and many other countries. It is truly an internationally developed standard. However, the contribution of several individuals is worthy of special recognition:
John Black and Craig MacKenna were the key individuals in the creation of the VMEbus specification. Their efforts, expertise, and perseverance guided the development of the VMEbus in its early forms.
Max Loesel and Sven Rau are recognized for proposing and demonstrating the feasibility of a Eurocard-based 32-bit backplane bus, and for guiding the re-implementation of VERSAbus into VMEbus.
Eike Waltz contributed extensively to the mechanical specifications.
Wayne Fischer, the first Chairman, guided the IEEE P1014 Working Group during its first three years.
Mira Pauker, Arlan Harris, and Shlomo Pri-Tal contributed to the development of Revision C of the specification.
Also worthy of recognition are Paul Borrill who contributed to the electrical specifications, Ken Smith who contributed to the mechanical specifications, and T.J. Chaney who was instrumental in preparing Appendix D.
And finally, special thanks to Tom Leonard who assisted Shlomo Pri-Tal as Vice Chairman of the P1014 Working Group.
In 1989, John Peters of Performance Technologies, Inc. developed the initial concept of VME64: multiprocessing address and data lines (A64/D64) on the VMEbus. This concept was shown for the first time in 1989 and placed in the VITA Technical Committee in 1990 as a performance enhancement to the VMEbus specification. In 1991, the PAR (Project Authorization Request) for P1014R (revisions to the VMEbus specification) was granted by the IEEE. Ray Alderman, Technical Director of VITA, co-chaired the activity with Kim Clohessy of DY-4 Systems.
At the end of 1992, the additional enhancements to VMEbus (A40/D32, Locked Cycles, Rescinding DTACK*, Autoslot-ID, Auto System Controller, and enhanced DIN connector mechanicals) required more work to complete this document. In 1992, the VITA Technical Committee suspended work with the IEEE and sought accreditation as a standards developer organization (SDO) with the American National Standards Institute (ANSI). The original IEEE Par P1014R was subsequently withdrawn by the IEEE. The VITA Technical Committee returned to using the public domain VMEbus C.1 specification as its base level document to which it added new enhancements. This enhancement work was undertaken entirely by the VITA Technical Committee resulting in ANSI/VITA 1-1994. The tremendous undertaking of the document editing was accomplished by Kim Clohessy of DY-4 Systems, the technical co-chair of the activity with great help from Frank Hom who created the mechanical drawings, and with exceptional contributions by each chapter editor.
Additional enhancements proposed to the VME64 Subcommittee were placed in VITA subcommittees; the VME64 Extensions Document. Two other activities began in late 1992: (1) BLLI (VMEbus Board-level Live Insertion Specifications), and (2) VSLI (VMEbus System-level Live Insertion with Fault Tolerance).
New activities began in 1993 using the base-VME architecture involving the implementation of high-speed serial and parallel sub-buses for use as I/O interconnections and data mover subsystems. These architectures can be used as message switches, routers, and small multiprocessor parallel architectures.
VITA’s application for recognition as an accredited standards developer organization of ANSI was granted in June 1993. Numerous other documents, including mezzanine, P2, and serial bus standards have been placed with VITA as the Public Domain Administrator of these technologies.
A detailed timeline, as well as more information about VMEbus history and specificiations can be found at the VITA website.