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Conference 49.910::kav30

Title:VAX on VMEbus: KAV30
Notice:Could have been as fast as 68K but its a VAX!
Moderator:CSSVMS::KAV30_SUPP
Created:Thu Apr 18 1991
Last Modified:Fri Aug 02 1996
Last Successful Update:Fri Jun 06 1997
Number of topics:159
Total number of notes:645

53.0. "Why a 68-pin SCSI conn?" by ISEQ::SOCONNOR (Stephen O'Connor) Wed Apr 29 1992 18:50

    Looking at the KAV30, I'm interested in the SCSI i/f, in particular the
    reasoning behind the 68-pin Honda connector used, where I would have 
    expected a 50-pin connector. 
    
    Any light shed on this would be appreciated
    
    Stephen
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53.1here's whyEICMFG::OLIVKarl-Heinz Oliv, @UFC, DTN 865-3056, EICMFG::OLIVThu Apr 30 1992 14:1338
    There are three basic types of SCSI connectors:
    
         o 50pol IEEE
         o 68pol miniature
         o 50pol miniature
    
    The 50pol IEEE connector which is defined in the DEC SCSI standard
    is simply to big to be used on a single slot module. The cutout on the 
    frontpanel would be too big and in case two SCSI modules are sitting
    next to each other there would be a conflict with the connectors on
    the cable.
    
    The 68pol Honda connector (does not neccessarily have to be Honda)
    is also defined in the DEC SCSI standard. It is widely used in the 
    western hemisphere and the so-called 'P-cable' which consists of 
    a SCSI cable, an IEEE connector and an 68pol Honda connector is a
    de-facto standard in industry. This connector usually can be found
    on SCSI initiators like the VAXstation 3100.
    
    The 50pol miniature connector is the Japanese version of the 68pol
    connector. It is mainly used in Far East but these days it finds
    more and more acceptance in Europe and the US. It is almost a shrunk
    version of the 50pol IEEE connector. At the time the KAV30 was being
    designed this connector was not defined in the DEC SCSI standard nor
    did the DEC SCSI Strategy Paper mention it. It was not supported at all
    by DEC. If we would have used it on the KAV30 the EIC would have to provide
    at least 6 different versions of SCSI cables, worldwide, for the next
    12 years.
    
    
    I agree, the 50pol miniature connector is technically the smartest 
    solution but not the best to be used on the KAV30 or probably other 
    DEC products.
    
    Regards,
    
    Karl-Heinz
    
53.2Is the BC09J-03 ok for kav30?CESARE::VIOLATue Sep 08 1992 15:586
    
    Could someone confirm to me if the BC09J-03 works with the KAV30's SCSI
    option? I didn't find any reference within the documentation
    available.
    
    	Thanks and regards, Alberto
53.3Your information is correct.BAYERN::WOLFFConformism is for little minds.Thu Sep 10 1992 17:451
	Julian.