FCO for KDA50-Q?

Noel Chiappa jnc at mercury.lcs.mit.edu
Mon Nov 3 08:12:43 CST 2014

     > From: Nigel Williams

    > I have some Emulex SD590 drives which require a controller like the DEC
    > KDA50-Q (M7164+M7165) or KDA50-QA.

Can one really plug such drives into an Standard Disk Interconnect directly,
or is the interface standard merely 'close'? (I don't know, merely raising
the question.)

    > the KDA50-Q has a rather bad (show-stopper) bug that was fixed in later
    > revisions, detailed here:

I'm not sure that's a fatal issue; maybe it just causes the controller to have
to re-read that last block? One could certainly write a hack work-around (re-read,
extending the transfer size one block).

    > I need either revision D1 or D2 of the M7164 module. What should I be
    > looking for on the board that would indicate it has had the FCO
    > applied?

Generally DEC indicates the ECO level by a stamp or something similar on the
module handle(s) on the back side.

I looked at a couple of M7164/M7165 board pairs which I have (which seem to
date, from the date codes on the ICs, to the '87-'88 timeframe - the ECO seems
to be Apr '84); the M7165's were both B14, and the M7164's were F4 and J04 (I
think - that was on a sticker in the right place, and I don't see anything

    > joined with the 40-pin and 50-pin cables) along with the cab-kit up for
    > sale

The two short cables are pretty generic, from what I can see. Ground plane
backing, but other than that, stock 40- and 50-pin flat cables. Those should
be easy to make.

The bigger issue is the cab-kit, which is almost unobtanium. There's a guy on
eBay selling a bunch of NOS UDA50 board sets, which include a cab-kit, which
is, I'm pretty sure, the same as the KDA50's - alas, the KDA50 User's Guide
doesn't give the part number, so I can't be positive (the UDA-50 one is
70-18455-6K). Alas, he wants a ton of money...

    > Thanks Jay for getting cctalk back online, well done!



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