1 Sep
2011
1 Sep
'11
12:24 a.m.
-----Original Message-----
From: cctalk-bounces at classiccmp.org [mailto:cctalk-
bounces at classiccmp.org] On Behalf Of Pete Turnbull
Sent: 31 August 2011 22:44
To: General Discussion: On-Topic and Off-Topic Posts
Subject: Re: RQDX3 DEVOFFLINE Problems
No, I don't think so. I can't remember what that does, but thre are lots
of links.
They might not be jumpers in the usual sense; they
might be tracks to
cut/join
on the PCB or wire links. Anytway, if you have any
sort of ohmmeter or
continuity tester, it's east to see if what I described is set up: check
for
continuity between pins 26 and 32 on each of J1...J4.
If your continuity
tester
isn't safe for use on logic circuits, just
disconnect the M9058, which is
probably going to be necessary to get at the pins anyway.
I used my digital multimeter to check the pins you mention, there is
continuity between pins 26, 28, 30 and 32 on each of J1 to J4. I also
checked that pin 4 on J9 is connected to pin 12 on J12, this is the RD 0 RDY
H signal, so the drive should be seen as ready by the RQDX3. I have also
checked that J5 pin 1 is connected to J12 pin 14 which is the select ack
(DRV SEL 0 ACK (L) ), so any selection confirmation should be coming back to
the RQDX3.
I suspect I need a way to monitor the signals actually passing across the
wires, I have a multimeter and an oscilloscope, but I am not sure of the
practicalities of how to get access to the signals, I suppose I need some
kind of "breakout" ribbon cable, but I don't want to ruin the existing
cables. Is there some standard technique for doing this kind of work? For
now I think I will just solder some diagnostic wires directly to the M9058.
Mentioning DS3 reminds me: I think that's the
normal setting for an
M9058 setup.
I have put it back to DS3, although it is my understanding that with an
M9058 it does not matter what setting you use.
I don't know if it helps much, but there are some diagrams and notes at
http://www.dunnington.u-net.com/public/RQDX/ (the .ps files are just the
original PostScript from which the PDFs were created).
Does the RD53 have a terminator resistor pack in it?
I just checked, and yes it does.
--
Pete Peter Turnbull
Network Manager
University of York