Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!ukc!inmos!inmos.co.uk!davidb From: davidb@inmos.co.uk (David Boreham) Newsgroups: comp.arch Subject: Re: the future of busses (and Futurebus) Message-ID: <13180@ganymede.inmos.co.uk> Date: 17 Dec 90 19:32:41 GMT Sender: rob@inmos.co.uk Reply-To: davidb@inmos.co.uk (David Boreham) Organization: none Lines: 28 In article <1178@shakti.ncst.ernet.in> shri@ncst.ernet.in (H.Shrikumar) writes: >In article > aglew@crhc.uiuc.edu (Andy Glew) writes: >> >>The likely successor to VME is VME-64. It's simple, fast, and >>available now. The likely successor to VME-64, if there is a lineal >>successor, will probably involve noticing that there are extra pins on >>most VME boards second connector... > > I was under the (evidently wrong) impression that VME-64 uses those pins! >Could you drop in a brief note on the pinout please ? VME-64 (which was first proposed by Performance Technologies) works on the principle that, during block transfers (BLT transfers), the address bus carries no useful signals after the initial address-phase. Consequently these 31 lines are free to carry data during the data-transfer-phase. Can't remember where the other bit comes from, but anyway, this means that during the data-transfer cycles of a BLT operation, it is possible to move 64-bits at a time, rather than the 32-bits possible with basic VMEbus. David Boreham, INMOS Limited | mail(uk): davidb@inmos.co.uk or ukc!inmos!davidb Bristol, England | (us): uunet!inmos.com!davidb +44 454 616616 ex 547 | Internet: davidb@inmos.com