Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!apple!voder!pyramid!csg From: csg@pyramid.pyramid.com (Carl S. Gutekunst) Newsgroups: comp.realtime Subject: Re: VME Board manufacturers? Message-ID: <139073@pyramid.pyramid.com> Date: 28 Dec 90 08:25:52 GMT References: <1990Dec10.180513.10032@ncsuvx.ncsu.edu> <137677@pyramid.pyramid.com> <1514@ehvie0.tq.ine.philips.nl> Organization: Pyramid Technology Corp., Mountain View, CA Lines: 20 >>The companies you named -- Motorola, Mizar, Force, et al -- seem to only >>make generic boards, too limited to be interesting for my purposes.... > >Philips' VMEgroup is also able to fit a board to your needs. You specify >what you want or don't want on the board, and we make it! It's called ASAP - >Application Specific Adaption of Products. With all respect, you are unfortunately demonstrating one of the most common misunderstandings that I run into when I talk to VME board manufacturers: that it is possible to take a general purpose platform (even one designed to be reworked for specific applications) and make it suitable for high-performance datacomm. Datacomm controllers need multiple internal busses, careful design of dual ported memory to reduce contention, and precise matching of the DMA controller to the serial interface chips, and a variety of more subtle needs. Look at the comm boards from CMC, SBE, and Performance Technology to get an idea of what I mean. (Systech and Metacomp make true communications cards, too; but they have so many problems that I wouldn't recommend using them as a model.)