WD2010 update

[Steve Johnson]

In article <1087 at cgh.UUCP> paul at cgh.UUCP (Paul Homchick) writes:
>...
>
>My experience is that some 7300's (at least mine) DO NOT work with a
>WD2010(x) (where x = A || B).  I have an early 7300, and a later 3B1.
>I bought two WD2010B's from Thad's group purchase, and the 7300 works
>fine with the WD1010A in it, but can't find a hard disk when a WD2010B
>is installed.  I can take that same WD2010B and put it in the 3B1 and
>have no problems.  This is the case for BOTH of my WD2010B's.
>
>There is evidently some sort of timing or logic problem, and I wish I
>knew what it was so I could fix it.  I bought a Maxtor XT2190 and
>installed the PAL5.1 mods in hopes of using > 1024 cyls and 15 heads.
>Since the WD2010B won't work in the machine, I ended up with 15 heads
>and only 1024 cylinders.
>
>In summary, I do not think it is true that you can plug replace a
>WD1010 with a WD2010 in all Unix-PCs.
>-- 

I'll be trying more tests to verify, but I tend to agree with Paul's
observations, above.  I have both WD2010 A's and B's.  On some machines
the A's work and not B's, and the converse (the errors are always seek
related with LOTS of recal's). I have *yet* to find a 7300 or 3B1 where
*both* revisions will work---it's always one or the other revision.
Are there any hardware guru's out there who can help find the definitive
answer?  My hardware expertise is severely limited when it comes to logic
design and analysis.

By the way, Thad Floryan's group buy was the source for my WD2010B and the
the firm previously posted (Somerville, Mass. --- arghh! what's their
name?) was the source for the WD2010A.  (Sorry, my memory is failing,
but the Somerville, MA firm was very prompt and seemed like nice
people!)  Anyway, Thad, the WD2010B you sent me is NOT fried, and is
working fine in a 3B1 (mine's a 7300).
Steven C. Johnson, Bell Communications Research, Inc.
{scj at casux4.custom.bellcore.com (128.96.153.2)} or {bellcore!navaho!scj}