29 Sep
2003
29 Sep
'03
12:07 a.m.
Tony Duell wrote:
Yes. Specifically, with G272A grant cards in slot D of rows 5-10 and
row 12,
an RX211 in C-F of row 11, and an M9302 terminator in AB of row 12, the
11/84 will boot from an RT-11 floppy in an RX02 drive. Replace the G727A
cards with G7273 dual-height cards, or add other boards, and the boot
aborts
with a Controller error.
Well, with
only the RX211 installed in its original slot, the M9302
terminator properly installed, and G7273's everywhere else, the CPU
still hangs. With G727A cards instead of G7273's, the RX02 will boot an
RT-11 installation floppy.
You are telling me it will work with the single-height grant cards in
slot D, but not with the dual-height ones in C and D? This is impossible -- the only difference between the
2 types of grant
card is that the dual-height ones also complete the NPG jumper. If it
works with the single-height ones, then the NPG chain must be complete
along the backplane. Adding a second 'jumper' (on the dual height card)
in parallel with the wire-wrapped on on the backplane can't make any
difference.
That's actually good to hear. It doesn't make sense to me either.
I've pulled
the backplane (H9277-A), and there are no broken traces or any other obvious
damage, but there are no jumpers between the first pins of slot C in
*any* row.
There is a lot of wire-wrap back there, but I'll be a couple of days
just mapping
it, much less figuring out the purpose.
It sounds like you have backplane problems. Maybe some
of the dual-height
cards aren't making proper contact. Maybe the slots you're putting them
in aren't satnadard Unibus slots (unlikely, but...) and the 'extra'
jumper is shorting a couple of signals that it shouldn't...
This machine was in production till about 2 months ago, and was
reportedly in
good health when decomissioned. However, it's not acting in a manner
that I'd
expect from anything I've read.
At this point, I'm looking at the 11/44 next to it an thinking that's
gotta be better.
:)
As bad as it sounds, the primary goal is to validate a couple dozen
RA60 disk
packs, not nw\ecessarily to bring up the 11/84. Whatever gets us there
quickest is best.
Doc