micropolis 1325BR drive in 3B2/300

[rohan kelley]

We tried all weekend to bring up a micropolis 1325 drive in a 3B2/300.
It is configured with Artmaster 6 series 33 CM190A motherboard.  According
to the 3B2 maintenance manual, that is the later revision without the
8 head limitation.  However the micropolis is 8 head 1024 tracks (I
think).

The drive will boot in a 400, but will not come up in the 300.  

I think it has to do with the terminating resistor.  The one connected
to the present drive (CDC 30mb) is a pin plug with 2 wires (red and
black) going to the terminal board at the XM chassis port.  (There is
no XM on this machine).  At the terminal board on the back plane, there
are 2 10 pin sockets, with the one fartherest from the 2 prong plug
(which terminates the resistor pack wires) populated with what is
apparantly a terminating resistor.  I assume if an XM is installed, you
move the terminating resister on this terminal board to the other 10
pin socket.

But the question is, where and how do you terminate the 1325.  There
is, just inside the data/command cable connectors on the rear edge of
the disk pc board, a small 10 pin, what appears to be a terminating
resistor pack.  There is no socket which is compatable with the plug at
the disk end of the 2 wires. 

Should the terminating resistor on the drive be removed or left in
place?  Should the 2 wire lead be disconnected from the terminal board
on the back plane?  Should the terminating resistor on the terminal
board on the backplane be removed?  HELP---

Inside the micropolis, there is a 6 (double) pin jumper block labeled:
w1, w2, ds 1-4.  I assume ds is disk selector.  Also, on the corner of
the pc board, there is a 2(double) prong jumper block labeled w7 and
w8.  When the disk arrived it was jumpered w8 and all 6 double pins wer
jumpered.  

I suspect the w1 and w2 should be jumpered and the drive number (eg. 1)
should be jumpered only.

In any case, with all combinations I could conceive the !(*!&&##$ thing
wouldn't work on the 300 but would on the 400.  Note, the 400 doesn't
have the peculiar 2 wire terminator block arrangement and I simply
removed the terminating resistor from within the drive (since it was
drive 0 of 2 in the 400 and drive 1 was jumpered) and the w8, w1 and 2
and ds 1 jumpers were jumpered. 

Any suggestions or help would be appreciated.

[Steve, I'm sure your listening s usual to this newsgroup; the fax article 
arrived. I appreciate your help.  I didn't have time to get into the floppy 
boot before dennis had to go back to the west coast (of FL) with his machine.]

A listing of the various errors were:
hard disk: Bad sanity word in VTOC on drive 0.
hard disk: unreadable CRC hard disk error: maj/min=17/16 (this was when all the 
ds jumpers were jumpered and the system thought it had another drive).

Then there were various SANITY FAILURES.  Understand this was the same
drive that ran OK on the 400.  I really believe it had to do with
improper termination somehow.

We reinstalled the CDC 30 meg drive and even had trouble getting that
up although it only hung after the copyright.  ( I tend to think that
somehow we corrupted the unix file or a master.d file and it will be
necessary to do a partial restore to get back in business.)

Help and suggestions (even dumb ones) would be appreciated.  Also,
please send a cc of any reply to (backbone)!uflorida!novavax!whitehse!drw.
=======================================================================
Rohan Kelley -- UNIleX Systems, Inc. (Systems and software for lawyers)
UUCP:  ...{gatech!uflorida,ucf-cs}!novavax!bigbroth!rk (office)
ATTmail:  attmail!bigbroth!rk
3365 Galt Ocean Drive, Ft. Lauderdale, FL 33308 Phone: (305) 563-1504

"Go first class or your heirs will" -somebodyelse
=======================================================================