Julian wrote...
How about this: Dig in the KW11-P manual if its
available and see if there
is any info on replacing a KW11-L with it. Maybe that will tell you where
that LTC L signal is.
Yes, but I'm missing something somewhere. I see the spot where the power
supply LTC L signal hits the cpu backplane. It comes from the brown wire, #7
on P2 at the top front. There's a trace that goes down from this to slot 1,
row C, pin R1. That's just peachy, and gives me a spot to test in order to
make sure the power supply is providing a clock signal.
But of course I want to make sure that signal is also present on the three
unibus slots built into the cpu backplane, so that my DL11-W can use it. So
I was looking for THAT pin. From eyeballing it and testing, it appears that
slot 1 row C pin R1 (the LTC "source") hits all the unibus slots on the cpu
backplane at row C pin D1. Ok, I'm fine there.
But here's where the KW11-P manual gets confusing. I'm only bringing this up
as a sanity check - It says that in order for the KW11-P to get the LTC (if
you even want to use that option, not required), you have to install a
jumper wire to the slot that the KW11-P is in to provide that signal. It
says the KW11-P expects to get it on CE1, and specifically says to run a
wire from CE1 to slot 1 row C pin R1 (on the 11/45). But why would they say
that if the LTC signal is available on pin CD1 right there in the same slot
already next to CE1?? Or better yet, why didn't they design the KW11-P to
get LTC from CD1 instead of CE1? This is the part that makes me think I'm
messing up somewhere.
I guess I could find prints for the DL11-W and see if in fact it's looking
to CD1 for LTC.
I can't put my hand on the DL11-W prints at the moment (I know I have
them sowewhere -- several times in fact), but all the notes I can find
say that the standard pin for the LTC L signal on an SPC slot is CD1. CE1
is a testpoint, normally unconnected.
In the early days of the Unibus things like this were not standardised,
so it's quite possible that the KW11-P needs the LTC L signal on CE1. But
I don't think the DL11-W expects it there.
Can you look at the DL11-W card to see what, if anything, is connected to
either of those pins?
-tony