19 May
2009
19 May
'09
10:13 p.m.
On May 19, 2009, at 9:55 PM, Josh Dersch wrote:
I typically use M9312s as the terminators (since it has boot ROMs
too). It has the appropriate jumpers. I tend to use M9302s only in
11/34s and 11/04s.
TTFN - Guy
Guy Sotomayor wrote:
Yes, there are jumpers for EIS & FIS too.
Bitsavers has all of the drawings in PDF.
I usually go off of the drawings, but I've done it enough that the
drawings are the best way to make sure you haven't missed anything.
I'd have to go back and lookup the drawings and compare it against
some of the board sets I have to make sure at this point though.
Memory is the 2nd thing to go with age...I forgot what the first one
is. :-)
On May 19, 2009, at 8:25 PM, Josh Dersch wrote:
Hmph; just got done configuring the boards for the MMU :). Is there
a good reference for how the jumpers should be configured for just
the basic CPU set? I have the engineering drawing sets (in TIFFs...
anyone have these in PDF? Tiff is annoying :)), and it indicates the
jumpers, and _some_ of them seem to indicate a "default" position,
but not all, and I don't know whether these are really defaults or
not. I know the MMU and the Stack Limit options require jumper
changes, did any other options require them? Hey all --
I'm one step closer to bringing my 11/40 back to life -- the front
panel is now responding and I can examine and deposit memory.
But the machine is only responsive without the Unibus terminator
(an M9302) installed. If it's installed, the front panel is
basically hung -- toggling "Start" causes a brief flurry of
activity, but that's the only thing that causes any response.
Without the terminator installed, the front panel more or less
works, I can examine and deposit memory, load the address
register, etc... but I can't get any toggled in code to run,
obviously -- it traps to the bus error vector at 00004.
(There's also an odd issue, which I doubt is related, but
Examining/Depositing does not correctly increment the address --
starting from 0, it's "0, 2, 6, 12, 16, 22, 26..." and if I start
at 1 it's "1, 3, 7, 13, 17, 23, 27...")
I currently have the CPU boards + MMU option installed in the
correct order with a SLU card in the SPC slot, and an M981
connecting to a 4-slot Unibus backplane with a single 64K MOS
memory card (M7891) in slot 2 -- all other slots have grant
continuity cards installed. The Unibus terminator is installed in
the last slot.
The first thing that I always do on an 11/40 is make absolutely
sure that all of the jumpers on all of the CPU boards are set
properly. DEC decided it wanted a lot of flexibility in 11/40
offerings. The result is a lot of jumpers spread between all of
the CPU boards. If they are not *all* set properly you'll get
strange behaviors.
If the boards are in an unknown condition, I would configure the
CPU to *not* use the MMU until you have the basic CPU running and
passing some basic tests before adding in the MMU back in (yea, I
know it's a pain because you have to solder/cut jumpers to change
the config).
Since the entire 11/40 CPU is microcoded (including the operation
of the front panel) you might want to use the appropriate KM11s and
single step through some of the micro code. This can help pin-
point the fault.
Just assembled one of the KM11s last night, now I just need to order
a couple of unibus extenders so I can use it :).
I also don't recall at this moment the M9302, but many of the
terminator boards have jumpers for the different types of pull-ups
for some of the processor signals. If the pull-ups are incorrectly
configured for the type of processor, the unibus can hang.
Remember the unibus needs to be terminated at both ends. However,
some signals are only to be terminated at one end (ie some CPUs
terminate the signals themselves and others don't so the terminator
at the end of the bus needs to be configured properly).
The M9302 does not appear
to have jumpers, and it doesn't appear to
be of the same vintage as the 11/40 (it has a "caution" label that
mentions an 11/34 or 11/04...) so maybe it is incorrect for use in
an 11/40.