1 Sep
2011
1 Sep
'11
12:31 a.m.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-
bounces at classiccmp.org] On Behalf Of Jerome H. Fine
Sent: 01 September 2011 02:59
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: RQDX3 DEVOFFLINE Problems
Whenever I used an RD53 in a BA123 with
the M9058 distribution board, I
always set the DS3 jumper for all hard drives. I don't know if the RD53
will
also work with the DS1, DS2 or DS4. However, it
definitely will work with
the
DS3.
I will put it back to DS3, but it didn't work when set that way. My
understanding of the docs is that the DS1-4 jumper is irrelevant when using
an M9058.
I agree that it is likely that the M9058 distribution is the most likely
problem
since that RD53 drive works with on a BA23 with the
same RQDX3 and all of
the cables. However, I don't know enough about hardware to really be
sure.
The M9058 has to be the focus for the moment as it is the only bit I have
not been able to test separately.
If you have a 6 button front panel, then it is also possible to use the
RQDX2 or
RQDX3 controller with a second RD53 in which case the
second RD53 MUST
have the DS4 jumper. It is also possible to set up an alternate circuit
which
can be used instead of a 6 button front panel in a
BA23, but the first
hard
drive MUST has the DS3 jumper and the second hard
drive must have the DS4
jumper.
If you forget and use both hard drives with the DS3 jumper and the WRITE
PROTECT buttons are not turned on, then I have noted (from personal
experience - once was enough to NEVER forget that sinking feeling) that
the
LLF (Low Level Format) is lost on BOTH hard drives.
At the moment I only have one drive in the machine, although I will be
adding a second one once I have cleared up this problem. That said, this is
not a BA23, but a BA123 and as I said above, I believe the M9058 handles
drive selection so that the DS jumper settings are irrelevant.
There has been mention of:
pins
Peter Turnbull wrote:
Does the RD53 have a terminator resistor pack in it?
R7 on a RD53 is a ZERO OHM resistor which the RQDX2 and RQDX3 require in
order to recognize the Micropolis 1325 (also 1335D) as an RD53.
It is possible to take the PC version of the Micropolis 1325 and solder in where the R7 resistor would be located. A wire wrap
between the pins is
then sufficient to take the place of the zero ohm resistor.
There have also been too many notes about the failure of the RD53 drive
due
to the heads being stuck to consider the RD53 as a
reliable drive.
My suggestion is to NEVER rely on the data on an RD53 once the drive is
powered down.
Yes, I am aware of the problem with the heads getting stuck. I have cleaned
out the sticky bumper and verified that the disk works in a MicroVAX 2000. I
am about to repeat the test in the 2000 just to be sure. However I am also
pretty sure the heads are not sticking because I don't hear the drive
spinning down until I actually switch the machine off.
Thanks
Rob