19 May
2007
19 May
'07
10:46 a.m.
"Jerome H. Fine" <jhfinedp3k at compsys.to> skrev:
Good catch! I didn't think of that one. Yes, you're right. In fact the
-JD and -JE don't even claim to be PMI memory, but just plain Q-bus
memory (according to the field guide). That's definitely not useful. You
need the -JB or -JC.
Rod Smallwood
wrote:
>Now that makes a lot more sense.
>
>So PMI memory choice is: (2 Max)
>
>MSV11-JD M8637-D 1 MB ECC PDP-11/84 or PDP-11/83
>MSV11-JE M8637-E 2 MB ECC PDP-11/84 or PDP-11/83
>
Jerome Fine replies:
I am not absolutely positive, BUT the probability is VERY
high that the above two PMI memory boards are ONLY for the
Qbus. I believe that you must use either the MSV11-JB or
the MSV11-JC within the PDP-11/84 system. It is probably confusing, but the CPU is the KDJ11-BF
which
is used in BOTH the PDP-11/83 (which I have and the memory
used is the MSV11-JD or the MSV11-JE) and the PDP-11/84
which you have. If you can find a KDJ11-BF along with two
MSV11-JC PMI memory boards, the cost will likely be much
less than a PDP-11/94 CPU.
That is probably correct as well. The 11/9x cpu boards are scarce and
expensive. The 11/8x cpu boards are more common and reasonably priced.
Johnny
--
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: bqt at softjar.se || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol
20 May
20 May
2:22 a.m.
Johnny Billquist wrote:
"Jerome H.
Fine" <jhfinedp3k at compsys.to> skrev:
Good catch! I didn't think of that
one. Yes, you're right. In fact the
-JD and -JE don't even claim to be PMI memory, but just plain Q-bus
memory (according to the field guide). That's definitely not useful.
You need the -JB or -JC. Rod Smallwood wrote:
>Now that makes a lot more sense.
>So PMI memory choice is: (2 Max)
>MSV11-JD M8637-D 1 MB ECC PDP-11/84 or PDP-11/83
>MSV11-JE M8637-E 2 MB ECC PDP-11/84 or PDP-11/83
Jerome Fine replies:
I am not absolutely positive, BUT the probability is VERY
high that the above two PMI memory boards are ONLY for the
Qbus. I believe that you must use either the MSV11-JB or
the MSV11-JC within the PDP-11/84 system. It is probably
confusing, but the CPU is the KDJ11-BF which
is used in BOTH the PDP-11/83 (which I have and the memory
used is the MSV11-JD or the MSV11-JE) and the PDP-11/84
which you have. If you can find a KDJ11-BF along with two
MSV11-JC PMI memory boards, the cost will likely be much
less than a PDP-11/94 CPU.
That is probably correct as well. The 11/9x cpu boards
are scarce and
expensive. The 11/8x cpu boards are more common and reasonably priced. 
11:02 a.m.
On 20/05/2007 03:22, Jerome H. Fine wrote:
The MSV11-JE can be used as either normal memory when
installed below
the CPU or as PMI memory when installed above the CPU.
Indeed, that's the stated design intention.
When I used 2 of these boards, I only used both above
or both below
the CPU. While I doubt that there would be any permanent damage, I
recommend that it not be tried, i.e. one board above the CPU and one
board below the CPU.
Again, yes. Normally, you'd not want to, because you'd lose the speed
advantage of PMI on the cards below the processor. However if you had a
BA23 backplane and wanted more than two memory cards, (eg because the
PMI cards you had were only 1Mbyte each) you would have to add the rest
as QBus memory, and an MSV11-J or two would be just as good as any other
fast QBus memory. It definitely wouldn't do any damage. In fact, the
MSV11-J manual gives an example (in the diagnostics section) of an
MSV11-JE used as PMI memory with an MSV11-P (QBus memory) in the same
system (and passing the diagnostics :-))
In my experience, I have always read that the MSV11-JD
and the
MSV11-JE are ONLY for use with the Qbus.
[ ... ]
I have also read that the MSV11-JB and MSV11-JC are
for use ONLY in a
PDP-11/84 system.
I've answered that in another reply :-)
The PDP-11/83, 2 MSV11-JE boards and 2 DLV11-J boards
uses 4 quad
slots while a PDP-11/93 uses only 1 quad ABCD slot
But the two DLV11-Js would take up two slots, if they were Q22-CD slots.
So in a BA123 box, with a CPU and two memory cards you only have one in
the last Q22-CD and the second one in a Q22-Q22 slot, leaving the CD
part of slot 4 empty (in a BA23, slot 4 is Q22-Q22 so you could put them
side-by-side). You'd be better off using a DHV11 or a DHQ11 (assuming
you have either of those).
I have also read that the MSV11-JD and MSV11-JE boards
should NEVER
be used together. Can anyone else confirm or deny this?
No reason not to, except that you'd end up with an unusual amount of
memory (3Mbytes). It certainly won't hurt anything, though of course
you would need to set the start address of the lower board to the
correct value. It's settable to any 16KB (8KW) boundary.
I suspect that 3 * MSV11-JD boards may be used in a
BA123 box with 4
ABCD slots, but since I don't have any MSV11-JD boards, let alone 3
of them, I can't verify this.
I don't recall ever trying *that*, but it too would work, so long as you
set the start address of each board correctly, and again you'd end up
with 3Mbytes, which is an unusual amount. The manual just says you can
use "one or more MSV11-J memory modules", without mentioning size or
maximum number.
--
Pete Peter Turnbull
Network Manager
University of York
11:04 a.m.
On 19/05/2007 11:46, Johnny Billquist wrote:
"Jerome H. Fine" <jhfinedp3k at
compsys.to> skrev:
Good catch! I didn't think of that one. Yes, you're right. In fact the
-JD and -JE don't even claim to be PMI memory, but just plain Q-bus
memory (according to the field guide). That's definitely not useful. You
need the -JB or -JC.
No, that's wrong. Both the Micronotes and the manual for the MSV11-J
are quite clear that they're all PMI memory, and that the difference is
that the ASICs in the early ones (the -JB and -JC) do not support
block-mode DMA (and imply that there may be other minor differences)
which mean that you should not use the early ones in a QBus. However,
the later ones work in both Unibus and QBus systems, as stated on page
1-3 of the MSV11-J manual. The 11/84 Technical Manual lists the
MSV11-JD and -JE as the memory for an 11/84 system.
This is also borne out by notes in the DECUServe archive, which also
notes that the -JB and -JC do actually work in a QBus system, but very
slowly with "fast" QBus DMA devices that want block-mode. The
microPDP-11 Maintenance Manual also lists them as PMI. The Field Guide
is wrong.
You can use any of them in an 11/84, but you should not use the -JB and
-JC in a QBus machine.
--
Pete Peter Turnbull
Network Manager
University of York
Rod
Smallwood wrote:
>Now that makes a lot more sense.
>
>So PMI memory choice is: (2 Max)
>
>MSV11-JD M8637-D 1 MB ECC PDP-11/84 or PDP-11/83
>MSV11-JE M8637-E 2 MB ECC PDP-11/84 or PDP-11/83
>
Jerome Fine replies:
I am not absolutely positive, BUT the probability is VERY
high that the above two PMI memory boards are ONLY for the
Qbus. I believe that you must use either the MSV11-JB or
the MSV11-JC within the PDP-11/84 system.
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