9 Nov
2015
9 Nov
'15
5:06 p.m.
On 11/9/2015 4:42 PM, jwsmobile wrote:
The M7940 has no cables, is open. I'm not sure if
the M9400 needs to
be pulled or not to run the system.
Thanks
Jim
On 11/9/2015 1:48 PM, Noel Chiappa wrote:
The 9400-YE has the cables that formerly went to the 11-780.
I'm not
sure what it does. The line below that I clipped out, about the
M7940-YA is for the adjacent card, and has no cable, just the open
blue one waiting for an IDE cable to the back for serial connections.
The M9400
seems to possibly be the Floppy boot and some other logic.
I've not pulled either of these since getting the system to examine them.
A post by Tony Duell some years back states that the M7940-YA may have
both a current loop and RS232 drivers for the port. That would make
things complicated, but might explain the puzzling extra bit in the Dec
module description about extra wires.
I may see if Megan Gentry is still around with any notes on what was put
in the Dec modules guide on World.std.com
thanks
Jim
From: Jim
Stephensn
> "extra wires to bring out clock & ..
110/300 speed change"
I am mainly asking if I want to hook up a
terminal, can I get
it going
with TD, RD and GND (or 2 3 7 on a DB25), or do I
need to loop
back any
of the other pins.
Well, without knowing how those extra pins work, it's very hard to
say. Given
that _apparently_ one could change the baud rate externally (which
means that
there's something in the cable - or at its other end - to do baud rate
selection), I'd _guess_ that a stock cable probably wouldn't work.
If you find a set of 11/780 prints, that _might_ include the specialized
cable for this beast, but short of that, you're talking signal
trace/etc time. I have several 4 port DLV boards, but want to go with
this as a
reference. I paid a bit too much for it because it was "working"
Yes, but it doesn't have the cable!
Trust me, swapping to a DLV11-J is a fully known, simple, approach -
not like
trying to work with a serial board with an unknown header pinout!
And that 'working' was some decades back! Who knows what the
situation is now! I
don't want to screw it up by replacing cards.
If all you do is replace the M7940 with an M8043 in the same slot, that
shouldn't present a problem (make sure the M8043 is configured
properly to be
the console, though; it is, however, very well documented).
I know even less about loading the backplane than
I do about
hooking up
> a serial cable. That's OK, I have recently run both
M7940's and M8043's in my QBUS
systems
here; they are a straight replacement (albeit using different cables - a
40-pin Berg/DuPont connector on the former, and 10-pin Berg/DuPont on
the second one).
Yep
I was hoping to get some idea whether the correct
cable might be
available from someone on the list first, and buy it, or
better, find
out how to spot them on ebay. I've had a lot
of luck with the
boards,
but none with finding listings for cabling.
Like I say, I expect the cable for the M7940-YA is a special item. As
for
cables on eBay - fuhgeddabahtit!
Well, that's not quite true: seller 'conflandard' has some console
cables for
sale, but I think only DLV11-J/11-23+ type (they are the same cable,
basically - the header pinout on the two cards is the same, the
difference is
that the stock 11/23+ cable allows baud rate selection on the back
panel -
but an 11/23+ _will_ work with a stock DLV11-J cable, provided the
board is
jumpered correctly).
I've _never_ seen a DL11 type cable (with the 40-pin Berg/Du Pont
connector)
for sale on eBay - well, not EIA ones. I think someone had an 20mA
one for
sale, once.
and trying the 4 port cards. Most of them came
from the cheap
scrap
guy, so I don't know the state of them as
well. I've seen some
people
found there were duds in the pile.
_Most_ of the cards I bought from him worked (I haven't been able to
try them
all, e.g. I don't have a working UNIBUS machine yet). The one
exception was a
DLV11-J on which two of the four serial ports didn't work.
Once you have a working machine/board set, it all becomes much
easier, of
course - you can swap boards around and see which ones are working.
(If you'd
like, you can send me the DLV11-J, and I'll either send you a known
fully-good one, or test yours and send it back, along with the
results. I've
done this for other people here.) > I can supply both null-modem and
non-null-modem cable
diagrams (for
> DB25 connectors, already worked out; I have
made DB9 serial
cables,
> but not for direct connection to a DLV11, but
could generate
those
> too).
I'd love that
OK, let me go unearth the cable diagrams - or I suppose I could just
look
at a cable, I have a couple of mostly-finished ones on the workbench
at the
moment! :-)
Noel