16 Sep
2019
16 Sep
'19
10:19 a.m.
The Microram was a multipurpose solid state memory chassis sold by EMM (Electronic
Memories and Magnetics) with what we called later in the 1970's a "personality
board" that plugged it into each different CPU's backplane. They sold a similar
system (maybe even plug compatible at some level) with core planes under
"Micromemory" brand name. I see we already have a "emm" directory in
bitsavers with docs about some of their core products.
16 Sep
16 Sep
10:45 a.m.
I would be interested in putting up the later docs
I wonder if Guy remembers what these were used for at CMU
On 9/16/19 10:19 AM, Shoppa, Tim via cctalk wrote:
The Microram was a multipurpose solid state memory
chassis sold by EMM (Electronic Memories and Magnetics) with what we called later in the
1970's a "personality board" that plugged it into each different CPU's
backplane. They sold a similar system (maybe even plug compatible at some level) with
core planes under "Micromemory" brand name. I see we already have a
"emm" directory in bitsavers with docs about some of their core products.
10:52 a.m.
The only thing that I believe would have used these would have been C.MMP. It had 1.2MB
of memory on it when I was there.
TTFN - Guy
On Sep 16, 2019, at 10:45 AM, Al Kossow via cctalk
<cctalk at classiccmp.org> wrote:
I would be interested in putting up the later docs
I wonder if Guy remembers what these were used for at CMU
On 9/16/19 10:19 AM, Shoppa, Tim via cctalk wrote:
The Microram was a multipurpose solid state
memory chassis sold by EMM (Electronic Memories and Magnetics) with what we called later
in the 1970's a "personality board" that plugged it into each different
CPU's backplane. They sold a similar system (maybe even plug compatible at some
level) with core planes under "Micromemory" brand name. I see we already have a
"emm" directory in bitsavers with docs about some of their core products.
10:59 a.m.
On Sep 16, 2019, at 1:52 PM, Guy Sotomayor Jr via
cctalk <cctalk at classiccmp.org> wrote:
The only thing that I believe would have used these would have been C.MMP. It had 1.2MB
of memory on it when I was there.
TTFN - Guy
It's been a long time since I've heard that reference. Did any of that software
get preserved? I wonder how hard it would be to make SIMH handle it.
paul
11:17 a.m.
I don?t know. It would be hard to replicate because of the custom HW and the custom uCode
that ran on the 11/40s. I even think that the 11/20s were modified as well. So trying to
figure that out would be ?interesting?. ;-) There is documentation on bitsavers that
covers the custom uCode HW for the 11/40s. The MMU as I recall was also radically
different than what was standard on 11/40s (and non-existant on 11/20s?the 11/20 changes
started to get to be so large, I believe later on they just ditched the 11/20s and C. was
just all 11/40s) to allow for really large memory spaces?I don?t recall what the maximum
possible memory on C. was, it did have 1.2MB while I was there.
And that?s just the HW. Hydra (the OS that ran on C.MMP) was a capability based system
(so you needed the proper capability to do anything). I recall at one point the grad
student who was doing work on the file system, ?lost? the root capability to the file
system?so it was no longer possible to create new file systems.
Since C.MMP was a ?one off? system, don?t expect (even if the SW survives) that there?s an
?installation guide?. ;-) It was pretty organic. Last and not least, all of the code
was either PDP-11 assembler or BLISS-11. It was all cross built from the (heavily)
modified TOP-10 systems that the CS department was running.
Hydra did a number of things that eventually lead to Accent and then Mach (which portions
are still in use in the guts of OS X). It was what we would call today a microkernel
system in that the kernel was the only thing that ran in privileged mode. Everything else
were user processes (file system, drivers, terminal system, etc). As I said, it was a
capability based system, so to use something you needed to have a capability to it (files
didn?t have Unix style permissions?if you had a capability to a file that capability
determined what you could do to the file). It had a number of reliability traits: it
could detect failures in HW and in SW and restart the appropriate failed item. In the
case of CPUs and memory, it could ?wall off? the failed component can cause diagnostics to
be run to either isolate the problem further or determine that the failure is no longer
present.
TTFN - Guy
On Sep 16, 2019, at 10:59 AM, Paul Koning
<paulkoning at comcast.net> wrote:
On Sep 16, 2019, at 1:52 PM, Guy Sotomayor Jr via
cctalk <cctalk at classiccmp.org> wrote:
The only thing that I believe would have used these would have been C.MMP. It had 1.2MB
of memory on it when I was there.
TTFN - Guy
It's been a long time since I've heard that reference. Did any of that software
get preserved? I wonder how hard it would be to make SIMH handle it.
paul
2:27 p.m.
First off, I've had a couple of follow-ups on these units, so they are
spoken for at this point.
The member with first dibs has also offered to scan the docs and see
that they make their way to Al.
I was wondering if these were c.mmp cast-offs? Guy: I encountered these
in the CMU computer club hardware room (Doherty Hall basement, I think?)
circa 1986. There were a couple of '11/40s adjacent, and those did have
some sort of custom writable control store cards.
The computer club was cleaning house, so I hauled off an '11/45 with CPU
spares that looked pretty stock, the aforementioned memory units, and a
rack mount Tek 'scope (about all I could convince my friends to help me
haul off campus at the time :-)
Not sure what ever happened to the rest of the equipment that was down
there. I know they had a couple of working Altos, on a thick net
segment with the old vampire transceivers that had the little round
glass windows in an aluminum box. And what must have been parts of an
earlier PDP (I remember a smallish teletype bolted on to a piece of
white Formica desktop.)
--FritzM.
2:53 p.m.
11/40?s were pretty ubiquitous at CMU when I was there and at least as far as I could
tell, were all configured pretty much the same (in that they all had custom writable
control store). I personally dealt with 3 different sets of 11/40s:
A single 11/40 with WCS that I used for doing some image processing work
2 11/40?s tied together with a prototype of C.MMP?s cross point switch
C.MMP (16-way PDP11?I saw it running with 4 11/20s and 12 11/40s). At the end the 11/20s
were removed and just the 11/40s remained.
There were only 2 11/45s that I knew of. The first was the ?front end? that sat in front
of all of the terminals and allowed connection to the various 10s (at the time there were
3: 2 KA10s and a KL10), C.MMP and CM*. The other 11/45 ran the XGP (Xerox Graphics
Printer)?granddaddy of laser printers so that we could get ?high quality? output (versus
line printer).
TTFN - Guy
On Sep 16, 2019, at 2:27 PM, Fritz Mueller via cctalk
<cctalk at classiccmp.org> wrote:
First off, I've had a couple of follow-ups on these units, so they are spoken for at
this point.
The member with first dibs has also offered to scan the docs and see that they make their
way to Al.
I was wondering if these were c.mmp cast-offs? Guy: I encountered these in the CMU
computer club hardware room (Doherty Hall basement, I think?) circa 1986. There were a
couple of '11/40s adjacent, and those did have some sort of custom writable control
store cards.
The computer club was cleaning house, so I hauled off an '11/45 with CPU spares that
looked pretty stock, the aforementioned memory units, and a rack mount Tek 'scope
(about all I could convince my friends to help me haul off campus at the time :-)
Not sure what ever happened to the rest of the equipment that was down there. I know
they had a couple of working Altos, on a thick net segment with the old vampire
transceivers that had the little round glass windows in an aluminum box. And what must
have been parts of an earlier PDP (I remember a smallish teletype bolted on to a piece of
white Formica desktop.)
--FritzM.
4:43 p.m.
There were only 2 11/45s that I knew of. ?The first
was the ?front end?
that sat in front of all of the terminals and allowed connection to the
various 10s (at the time there were 3: 2 KA10s and a KL10), C.MMP and
CM*. ?The other 11/45 ran the XGP...
They had moved on to a Xerox 9700 and DECSYSTEM-20s behind Micom port
selectors by the time I first rolled up there in 1984. CS still had a
cluster of PERQs in Wean Hall.
Not too long after that, the DECSYSTEM-20s were decom'd, and the old
terminal clusters were converted over to IBM PCs, Macs, and IBM RT
Andrew workstations.
--FritzM.
17 Sep
17 Sep
8:17 a.m.
m?n 2019-09-16 klockan 11:17 -0700 skrev Guy Sotomayor Jr via cctalk:
And that?s just the HW. Hydra (the OS that ran on C.MMP) was a
capability based system (so you needed the proper capability to do
anything). I recall at one point the grad student who was doing work
on the file system, ?lost? the root capability to the file system?so
it was no longer possible to create new file systems.
Which also means that for boot-strap you need to create a correct fully
populated binary dump of all the file system in the system.
A dump which is sane which regards to capabilities and user
capabilities ....
It is a little like kick-starting a database system ie writing the
system database (pg_system) into such a state that is it possible to
correctly run for example:
---
create tablespace 'stefan';
create schema 'pg';
---
and so on...
9:13 a.m.
On Sep 17, 2019, at 8:17 AM, Stefan Skoglund
<stefan.skoglund at agj.net> wrote:
m?n 2019-09-16 klockan 11:17 -0700 skrev Guy Sotomayor Jr via cctalk:
The problem (and I?d be thrilled to be wrong) is that the probability of having
a binary dump of Hydra is 0 for small values of 0. Part of the issue is that the
C.MMP has a few RP06 drives (4-6?). If it were ever saved, it would have to
be to 9-track tapes and I don?t recall any sort of backup facilities. The RP06
packs *might* still be around but I wouldn?t hold out too much hope for them
either.
TTFN - Guy
And that?s just the HW. Hydra (the OS that ran on C.MMP) was a
capability based system (so you needed the proper capability to do
anything). I recall at one point the grad student who was doing work
on the file system, ?lost? the root capability to the file system?so
it was no longer possible to create new file systems.
Which also means that for boot-strap you need to create a correct fully
populated binary dump of all the file system in the system.
A dump which is sane which regards to capabilities and user
capabilities ....
It is a little like kick-starting a database system ie writing the
system database (pg_system) into such a state that is it possible to
correctly run for example:
---
create tablespace 'stefan';
create schema 'pg';
---
and so on?
1923
days inactive
1924
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9 comments
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