[comp.sys.dec] RL02 question

paulf@bodega.stanford.edu (Paul Flaherty) (02/15/90)

I recently acquired an 11/730 with the standard pair of RL02s (hey it was
free, and working).  After having moved the little beastie a block, the
drives fault on powerup.  Anyone have any ideas what might be causing this?

One suspect is the drive access arm; back when I used to hack pdp-11s with
rk06s, we used to have the same problem.

Also, anyone know where I can get the diagnostic / microcode tapes for
an 11/730?

--
-=Paul Flaherty, N9FZX/VK2WYX | "Unix could use a more user-friendly front
->paulf@shasta.Stanford.EDU   |  end.  Does anyone have a card punch handy?"

stewart_andy@decus.com.au (Andy Stewart) (03/03/90)

In article <1990Feb15.023941.11459@Neon.Stanford.EDU>, paulf@bodega.stanford.edu (Paul Flaherty) writes:
> I recently acquired an 11/730 with the standard pair of RL02s (hey it was
> free, and working).  After having moved the little beastie a block, the
> drives fault on powerup.  Anyone have any ideas what might be causing this?

Paul, 

I went to my QBUS based PDP-11/23 system which uses the RLV11 controller
and disconnected the last drive in the chain.  When power was applied,
that drive's Fault and unit number lights lit up.  After the normal delay,
the load light lit (Tongue twister :-) on all drives.  When reconnected into
the chain, the fault and unit number lights went out.

The RL02 and RA80 drives typically used on the VAX-11/730 were 
connected to the RB730 Integrated Disk Controller (IDC).  I suggest you
check that the daisy chain cable is plugged in all the way to the board.

Check also that the head lock plate has been swung out of the way.
If you can't open up the drive door under power, undo the two Philips 
head screws on the right hand side of the drive and pull the exposed pin down.
Loosen the screw that holds the plate in and let it drop down then tighten
the screw again.  

Andy Stewart
(Sorry if I'm teaching you to suck eggs).

jdudeck@polyslo.CalPoly.EDU (John R. Dudeck) (03/05/90)

In article <916@decus.com.au> stewart_andy@decus.com.au (Andy Stewart) writes:
>In article <1990Feb15.023941.11459@Neon.Stanford.EDU>, paulf@bodega.stanford.edu (Paul Flaherty) writes:
>> I recently acquired an 11/730 with the standard pair of RL02s (hey it was
>> free, and working).  After having moved the little beastie a block, the
>> drives fault on powerup.  Anyone have any ideas what might be causing this?
>
I'm no great expert on DEC hardware, but I have seen this problem before.
Of course, something may have failed in the drives, but my experiences
showed that RL02's are quite sensitive to the cable arrangement.  Of course
you have to have a terminator block connected at the end of the chain.  I 
suppose you have it in place.  But I found with one set of drives that
it made a difference which order the drives were physically daisy-chained
in.  I suppose that one or more of the drives was actually out of spec,
but as long as I got the right combination of connections, it worked fine,
and has been for years.  Also, I also discovered that it is possible to
bend the contacts inside the connectors so that they don't make contact.

-- 
John Dudeck                           "You want to read the code closely..." 
jdudeck@Polyslo.CalPoly.Edu             -- C. Staley, in OS course, teaching 
ESL: 62013975 Tel: 805-545-9549          Tanenbaum's MINIX operating system.

gordon@prls.UUCP (Gordon Vickers) (03/06/90)

>In article <1990Feb15.023941.11459@Neon.Stanford.EDU>, paulf@bodega.stanford.edu (Paul Flaherty) writes:
> I recently acquired an 11/730 with the standard pair of RL02s (hey it was
> free, and working).  After having moved the little beastie a block, the
> drives fault on powerup.  Anyone have any ideas what might be causing this?

    I haven't any helpful advice but if you find that something is wrong
  with the drive, I can probably sell you one for less that the repair
  cost of your current drive.

    I also have a completely working PDP 11/34 with three drives that I'd
  like to sell REAL CHEAP: first reasonable offer.

Gordon Vickers 408/991-5370, at Signetics  (Sunnyvale, California, USA )
{mips|pyramid|philabs}!prls!facv01!gordon       ** All disclaimers apply **
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