4 Nov
2006
4 Nov
'06
11:04 p.m.
It would appear that the slots designated "MEMORY" in the 11/44 (slots 9-12
in the *system* backplane) are actually "Extended Unibus" slots. My reading
is that these slots allow 22 bits of memory addressing instead of 18.
So, of they are still "unibus" slots, does that mean that if there is one
board in slot 9, that slots 10-12 should have grant continuity cards (G727)?
If they are unibus slots I would certainly think so, but they are designated
for memory only... and I can't find any reference to using grant cards there
for non-populated memory slots.
Anyone know off the top of their head?
Jay
5 Nov
5 Nov
midnight
At 10:04 PM -0600 11/4/06, Jay West wrote:
It would appear that the slots designated
"MEMORY" in the 11/44
(slots 9-12 in the *system* backplane) are actually "Extended
Unibus" slots. My reading is that these slots allow 22 bits of
memory addressing instead of 18.
So, of they are still "unibus" slots, does that mean that if there
is one board in slot 9, that slots 10-12 should have grant
continuity cards (G727)?
If they are unibus slots I would certainly think so, but they are
designated for memory only... and I can't find any reference to
using grant cards there for non-populated memory slots.
Anyone know off the top of their head?
Jay
I'm pretty sure you don't need grant cards, but my /44 is buried.
The /44 can use up to 4MB, and IIRC, I only have 1MB. I needed the
grant cards, but in slots where options had been removed.
It's just like you don't need any kind of grant card in the CPU slots
if you don't have the extended CPU options installed.
Zane
--
| Zane H. Healy | UNIX Systems Administrator |
| healyzh at aracnet.com (primary) | OpenVMS Enthusiast |
| MONK::HEALYZH (DECnet) | Classic Computer Collector |
+----------------------------------+----------------------------+
| Empire of the Petal Throne and Traveller Role Playing, |
| PDP-10 Emulation and Zane's Computer Museum. |
| http://www.aracnet.com/~healyzh/ |
12:05 a.m.
Zane wrote....
It's just like you don't need any kind of
grant card in the CPU slots if
you don't have the extended CPU options installed.
I don't think it is necessarily the same, because cpu slots aren't unibus
slots. The extended unibus slots that are for memory in the 11/44 ARE unibus
slots.
But more to the point, the manual for the MS11-P shows that the M8743 cards
tie together BG4-7 and NPG ON THE CARD. If they do that, then why wouldn't
one need a grant card if no module is present?
Jay
1:24 a.m.
Zane H. Healy wrote:
At 10:04 PM -0600 11/4/06, Jay West wrote:
You don't need grant cards in the 11/44 backplane slots 9-12 since they
are not SPC slots. The AB portion of the slot is 'extended unibus' EUB
(adds address lines 18-21 for 22b addressing) but the CDEF sections are
not SPC slots. If they are not used for memory they should be left
empty; you can put a grant card (either type) in these unused slots --
it won't hurt anything, but it is not necessary. Empty memory slots
cannot be used for UNIBUS SPC modules either.
Only the last two quad slots 13,14 CDEF in the 11/44 backplane are SPC
and these require G727A/G7273 grant cards depending on whether the NPG
wire has been removed.
The modules have the grant propagation lines intact because they could
*theoretically* go in a MUD (modified unibus, 18b, with associated SPC
section) or an EUB (22b) slot. These modules work in the 11/44
(dedicated EUB memory) slots or the 11/24 (MUD/EUB/SPC slots) which need
grant propagation.
It would appear that the slots designated
"MEMORY" in the 11/44
(slots 9-12 in the *system* backplane) are actually "Extended Unibus"
slots. My reading is that these slots allow 22 bits of memory
addressing instead of 18.
So, of they are still "unibus" slots, does that mean that if there is
one board in slot 9, that slots 10-12 should have grant continuity
cards (G727)?
If they are unibus slots I would certainly think so, but they are
designated for memory only... and I can't find any reference to using
grant cards there for non-populated memory slots.
I'm pretty sure you don't need grant cards, but my /44 is buried. The
/44 can use up to 4MB, and IIRC, I only have 1MB. I needed the grant
cards, but in slots where options had been removed.
It's just like you don't need any kind of grant card in the CPU slots
if you don't have the extended CPU options installed.
9:57 a.m.
Don wrote....
The modules have the grant propagation lines intact
because they could
*theoretically* go in a MUD (modified unibus, 18b, with associated SPC
section) or an EUB (22b) slot. These modules work in the 11/44
(dedicated EUB memory) slots or the 11/24 (MUD/EUB/SPC slots) which need
grant propagation.
Ok, gotcha. That makes sense. Thanks!
Jay
10:55 a.m.
You don't need grant cards in the 11/44 backplane
slots 9-12 since they
are not SPC slots. The AB portion of the slot is 'extended unibus' EUB
(adds address lines 18-21 for 22b addressing) but the CDEF sections are
not SPC slots. If they are not used for memory they should be left
empty; you can put a grant card (either type) in these unused slots --
it won't hurt anything, but it is not necessary. Empty memory slots
cannot be used for UNIBUS SPC modules either.
Only the last two quad slots 13,14 CDEF in the 11/44 backplane are SPC
and these require G727A/G7273 grant cards depending on whether the NPG
wire has been removed.
The modules have the grant propagation lines intact because they could
*theoretically* go in a MUD (modified unibus, 18b, with associated SPC
section) or an EUB (22b) slot. These modules work in the 11/44
(dedicated EUB memory) slots or the 11/24 (MUD/EUB/SPC slots) which need
grant propagation.
FWIW, my "PDP-11/44 System Technical Manual" (EK-KD11Z-TM-001,
1980) provides this information on pages 3-1 and 3-6.
De
12:34 p.m.
At 10:55 AM -0500 11/5/06, Dennis Boone wrote:
FWIW, my "PDP-11/44 System Technical Manual"
(EK-KD11Z-TM-001,
1980) provides this information on pages 3-1 and 3-6.
De
Jay,
If you don't have a copy, I believe Al has a copy of this up on bitsavers.
http://www.bitsavers.org/pdf/dec/pdp11/1144/
Personally I wouldn't want to try to run a /44 without a copy of the
Tech Manual, it was invaluable in getting my system up and running.
Zane
--
| Zane H. Healy | UNIX Systems Administrator |
| healyzh at aracnet.com (primary) | OpenVMS Enthusiast |
| MONK::HEALYZH (DECnet) | Classic Computer Collector |
+----------------------------------+----------------------------+
| Empire of the Petal Throne and Traveller Role Playing, |
| PDP-10 Emulation and Zane's Computer Museum. |
| http://www.aracnet.com/~healyzh/ |
1:01 p.m.
Zane wrote....
If you don't have a copy, I believe Al has a copy
of this up on bitsavers.
http://www.bitsavers.org/pdf/dec/pdp11/1144/
Personally I wouldn't want to try to run a /44 without a copy of the Tech
Manual, it was invaluable in getting my system up and running.
Thanks for the pointer Zane, but I did(do) have the manual - read it before
asking my question too. What I saw in that manual AND in concert with the
M8743 documentation was unclear to me.
It's not that I don't read the manuals folks, it's that what I saw didn't
make sense to me. HENCE my question.
Jay
12:58 p.m.
Dennis wrote....
FWIW, my "PDP-11/44 System Technical Manual"
(EK-KD11Z-TM-001,
1980) provides this information on pages 3-1 and 3-6.
Acutally, I read that manual, and was looking at exactly pages 3-1 and 3-6.
Neither one of those pages elucidates the reason that Don explained and the
crux of my question. In addition, the manual for the memory boards raised
the issue in my mind because they were documented to tie the bus grant
signals together.
Jay
6509
days inactive
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days old
8 comments
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participants (4)
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ak6dn＠mindspring.com -
drb＠msu.edu -
healyzh＠aracnet.com -
jwest＠classiccmp.org