10 Dec
2002
10 Dec
'02
8:59 p.m.
A google search for M7095 turned up www.jtcomputer.com so I already sent an
email earlier tonight inquiring about a M7095. Are they a decent place to
do business with?
I just tried an old barrel key from a Kryptonite lock and it does work (a
little rough to insert & remove) so that takes care of that problem.
I didn't get any disk subsystems. The rules of the surplus department where
I aquired the CPU dictate that disk drives be destroyed before systems are
made available to the public.
The I/O cards that were installed were an M7521 DELUA ethernet, CMD
CDU-720/TM SCSI, M7819 DZ11-A octal serial, Digital Pathways TCU-150 clock
module?, M7258 LP11, Datasystems DLP-11.
The CPU came in a rack that is about three times the height of the the
PDP11/44 and about 1.25x as wide. It's a Digital rack, but I didn't see a
model number on the rack. The rack itself really heavy. They used a
forklift to load it into my van and I was able to get it out of the van
myself with the careful application of gravity, but there was no way I would
have been able to get it into the house. I did download the User's Guide /
System Technical Manuals which came in handy when I got stuck trying to
figure out how to release the rack slide lock mechanism. Now I've got the
CPU out of the rack and in the house were I can work on it.
The rack did have bulkhead connectors and cables for the M7521 DELUA
ethernet (AUI) and the console (DB25). The rack had a couple of other
connectors I didn't recognize, I think they must have been cabled up to the
M7819 DZ11-A and M7258 LP11. There is no breakout pod for the M7819 DZ11-A.
The DLP-11 had a very long LPT ribbon cable attached. It might have
originally been attached to a huge Genicom? printer that was also available
at the surplus place, but I passed on that at the time.
I inspected the insides before thinking about trying to power up the CPU and
when I realized the M7095 was missing (I wonder why it was removed?) I
didn't go any further. Also, while the power supply is configured for
120VAC it has the high current (20A) plug with one of the lugs rotated 90
degress and I don't think I have any compatible outlets in my house so that
is yet another challege to solve.
If I do get the CPU running, then I'll have to figure out what software I
should try to run on it. I don't really know much about PDP11 software yet.
-Glen
From: John Lawson <jpl15(a)panix.com>
Reply-To: cctalk(a)classiccmp.org
To: cctalk(a)classiccmp.org
Subject: Re: Acquired a PDP11/44, but missing M7095
Date: Wed, 11 Dec 2002 01:58:00 -0500 (EST)
On Tue, 10 Dec 2002, Glen S wrote:
_________________________________________________________________
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I recently acquired a surplus PDP11/44 (my first
real PDP11) and it
appears
that it is in reasonably good condition, but
after opening it up to
check
out what modules were installed I realized that
it is missing the M7095
control logic module, one of the 5 core modules that make up CPU.
Anyone
know where I can find one of these at a
reasonable price, or have a good
spare that they care part with?
Congratulations! Join the Club.... ;}
A lot of DEC Stuff is listed here ( they also sell on eBay ).
www.jtcomputer.com shows a M7095 - $25.00
Also, the keyswitch for the front panel is missing. Anyone know where I
can
find one of those, or is there an easy way to
bypass the switch?
Any barrel key will work... one of mine has flutes, but the other ( a
red plastic one marked 'anti static' has no flutes at all.
On the plus side a CMD CDU-720/TM SCSI controller
was installed so if I
get
the CPU running I hope it won't be too hard
to connect it to a SCSI hard
drive and tape drive.
Depends on the OS you use, and how you generate the new system.
Did you get any other peripherals, especially the disk subsystems that
were once attached? Is the console serial cable present? ( a longish
cable terminating in a DB25). Any other I/O cards? Have you powered the
machine on yet? Be careful of the power supply - they're REALLY deadly
with the covers off. ALso be sure the fan deck is running.
Oh yeah - did you get any Doc with the system... or can you get a copy
of the PDP-11/44 System Technical Manual and the System User's Guide...
these will be most helpful getting the beast to wake up.
Keep us informed of your progress... there are several /44s up and
running among us.
Cheers
John 
11 Dec
11 Dec
6:52 a.m.
On Wed, 11 Dec 2002, Glen S wrote:
A google search for M7095 turned up www.jtcomputer.com
so I already sent an
email earlier tonight inquiring about a M7095. Are they a decent place to
do business with?
I personally dunno yet - one of my two /44s has a bad data paths card in
the CPU, and I was going to call them, but haven't yet.
Any other ListMembers done any business with J. T. Computers? for DEC
stuff?
I didn't get any disk subsystems. The rules of the surplus department where
I aquired the CPU dictate that disk drives be destroyed before systems are
made available to the public.
Sigh. Generally there's no *real* reason for this... just the "fix
everything with a hammer" solution. Too bad...
The I/O cards that were installed were an M7521 DELUA ethernet, CMD
CDU-720/TM SCSI, M7819 DZ11-A octal serial, Digital Pathways TCU-150 clock
module?, M7258 LP11, Datasystems DLP-11.
The Peripherals Handbook (I have the 1981 version) shows a bunch of
different LP11 systems, and most of them are big clunky line printers that
would typically be used in a large multi-user machine. Most of them come
with that 30 meter I/O cable.
BTW - how many slots / backplanes are curently installed? How many free
slots? How many BUs Grant cards are in open slots? It is also possible
that you will need access to the underside of the machine at some time (to
attach/remove NPR jumpers) so don't mount it where that would be
difficult, until you have the System stable and configured the way you
want it.
The CPU came in a rack that is about three times the
height of the the
PDP11/44 and about 1.25x as wide.
These are rather bulky, unless you have the RL02 drives, or the RL02
and RAxx that came in it. The it's REALLY heavy. The DEC cabs are built
very nicely, but it's probably more space-efficient to put the system in a
standard 19" rack (DEC H960-type if you can find one). As long as the rack
slides can attach at the front and back, any rack will work that will
support the eventual weight. Or, if you're going to run the system with
small SCSI drives only, then it can just sit on the table. One of mine has
a sheet of 1/8" plexiglass instead of the metal top cover, so you can see
in when it's running.
degress and I don't think I have any compatible
outlets in my house so that
is yet another challege to solve.
Not too bad - get a 15A plug from any of the Home DIY places or a big
hardware store. Take off the (should be attached with various screws and
clamps) existing 20A plug and attach the 15A one. Remember that the the
Black (hot) wire goes to the Brass terminal, the White (neut) wire goes to
the Silver terminal, and the Green (gnd) wire goes to the green (or black)
Ground terminal.
Your CPU, configured as it is now, will draw maybe 6 or 7 amps from the
wall at 120V, so you're good to go.
If I do get the CPU running, then I'll have to figure out what software I
should try to run on it. I don't really know much about PDP11 software yet.
I would suggest downloading the Supnik suite of emulators
(www.simh.trailing-edge.com) to get a flavor of the various OSes available
for the 11/44 series. Once you have the SCSI card running (very fortunate
find, BTW!) then you can begin building the system from there, as well as
using the simulators to collate files for installation on the /44.
Cheers
John
7:18 a.m.
On Wed, Dec 11, 2002 at 12:53:55PM -0500, John Lawson wrote:
Any other ListMembers done any business with J. T. Computers? for DEC
stuff?
I purchased a couple of RL02K-DC cartridges from them a few
months ago for $25.00 each plus shipping. Great service. Fast
delivery.
--
---------------------------------------------------------------------
Christopher L McNabb Tel: 540 231 7554
Operating Systems Analyst Email: cmcnabb(a)vt.edu
Virginia Tech ICBM: 37.205622N 80.414595W
GMRS: WPSR255 ARS: N2UX Grid Sq: EM97SD
11:33 a.m.
didn't go any further. Also, while the power
supply is configured for
120VAC it has the high current (20A) plug with one of the lugs rotated 90
degress and I don't think I have any compatible outlets in my house so that
is yet another challege to solve.
You should, with a properly constructed extension cable, be able to run it
off of your dryer circuit. My PDP-11/44 is in my parents Garage, and that's
how it gets it's power. That's enough to power the CPU, two RL02's and some
other stuff. Looking at the CPU manual you should be able to get a rough
idea of how much current the system will really draw.
Zane
12:34 p.m.
On Wed, 11 Dec 2002, Zane H. Healy wrote:
<sellam_mode>
Jesus H Kraist!!!!! Zane, you need to stick with shit you know about,
and leave the electrical advice to folks who understand the difference
between voltage and current.
DO NOT plug your 120v PDP11 into a 220V Dryer Outlet!!!!!
DO NOT plug your 120v PDP11 into a 220V Dryer Outlet!!!!!
(repeat this until it sinks in!)
didn't go
any further. Also, while the power supply is configured for
120VAC it has the high current (20A) plug with one of the lugs rotated 90
degress and I don't think I have any compatible outlets in my house so that
is yet another challege to solve.
You should, with a properly constructed extension cable, be able to run it
off of your dryer circuit. My PDP-11/44 is in my parents Garage, and that's
how it gets it's power. That's enough to power the CPU, two RL02's and some
other stuff.
Most likely your system is configured for 220VAC operation, by use of
the switches on the backs of the various units - or, what is less likely,
is that your folks have a 120V dryer...
BUT There is a huge difference between 'enough power' and 'correct
voltage'!!! and I don't get the sense that your "advice"
discriminates
between the two....
Looking at the CPU manual you should be able to get a
rough
idea of how much current the system will really draw.
No, not really! Having the docs on all installed cards, and adding up
the current draws for +5 and +12 in amps, will give you a rough idea of
what the 11/44 mains draw will be, IF you can translate what the
power supply will draw from the mains given that particular load.
PEOPLE: *Please* check your facts before giving advice about
potentially disastrous hook-ups like this!!!!
This is a good way to permanently fry someone else's vintage hardware,
and it's certainly one of the drawbacks of a forum where people's opinons
might be taken as gospel when, in fact, the opinions are worth what one
pays for them...
DO NOT HOOK YOUR 120V PDP11 INTO A 220V DRYER OUTLET!!!!!
</sellam_mode>
I'm scared now...
John
1:12 p.m.
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3:13 p.m.
Tony wrote:
(2) I was under the impression that US dryers, while
using 230V for the
heating elements, used 115V for the timer. And that US domestic mains
was a centre-tapped (The tap being called 'neutral') 230V supply.
In which case, if there's a neutral feed to the dryer socket which can
carry the same current (20A) as the 2 live feeds (one from each side of
the mains), then you could run the 11/44 between one live feed and
neutral. This probably breaks code in a dozen places, but....
US residential wiring normally does use 240V split phase, but it is
uncommon for there to be four-conductor receptacles with both hots
(for 240V), the neutral, and the ground (e.g. NEMA 14-20R or 14-30R
receptacles for 20-amp and 30-amp circuits, respecitvely). Instead, a
common outlet for a clothes dryer has only three conductors, with two hots
and ground (e.g. NEMA 6-20R or 6-30R receptacles for 20-amp and 30-amp
circuits). Older homes might have a two-wire receptacle with no ground,
such as NEMA 2-20R or 2-30R, but this is probably not allowed by code any
longer.
Thus a typical US residential clothes dryer outlet can't be used to
directly power 120V equipment.
1:14 p.m.
Most likely your system is configured for 220VAC
operation, by use of
the switches on the backs of the various units - or, what is less likely,
is that your folks have a 120V dryer...
No, the system is setup for 120V. I take it, that it is the Washing
Machine that uses 120V, since my memory would appear to be faulty.
DO NOT HOOK YOUR 120V PDP11 INTO A 220V DRYER
OUTLET!!!!!
Agreed, I'm just trying to suggest where to find a circuit that can handle
the Amperage. I would never suggest trying to use an incorrect Voltage, and
I would hope anyone trying to mess with such a system would know better.
I'm scared now...
Be more afraid, I'm an ex-Electrician :^/
Zane
7895
days inactive
7895
days old
7 comments
6 participants
participants (6)
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ard＠p850ug1.demon.co.uk -
cmcnabb＠4mcnabb.net -
eric＠brouhaha.com -
glenslick＠hotmail.com -
healyzh＠aracnet.com -
jpl15＠panix.com