I'm working my way through a Tektronix 4006 terminal purchased of eBay right now. First stage is the low voltage power supplies, and I noticed right away that one of the multi-stage electrolytic filter caps there was running quite hot (this was with downstream electronics isolated, and a 40 ohm dummy load on the +20V supply per recommendation in the service manual.)
The cap in question is a multi-section Mallory can, 150 at 400 / 150 at 250, used to filter the +185 and +320 unregulated supplies. It is C395 A/B on the schematics, Tek part 290-0549-00, Mallory part 68D20193.
This terminal is so beautifully engineered inside that it would be a real shame to replace this with some sort of ugly bodge. Any part-sourcing gurus out there able to steer me in a good direction here? I have found the part listed in the various online NSN aerospace cross-referencing sites, but haven't bothered to ask for a quote from any -- I'm guessing cynically that "RFQ" + "Aero..." = 5 zillion dollars for one piece... :-) Has anybody here used one of these sites successfully?
cheers,
--FritzM.
The Computer Museum of America in Roswell GA (400 miles) has 2 working 029s. Don?t know the condition of the ribbons. Contact Lonnie Simms via info at computermuseumofamerica.org. Tell him his CA IBM benefactor sent you. I hope you have black cards. If not, let me know.
Otherwise you could try http://www.kloth.net/services/cardpunch.php and print the JPEG on heavy stock.
Donald
Date: Wed, 7 Aug 2019 18:10:32 -0400
From: Chip Davis <chip at aresti.com>
To: cctalk at classiccmp.org
Subject: I need a keypunch (briefly)
Message-ID: <5c1abccc-5548-057d-fa0c-0b6be9d0c2c8 at aresti.com>
Content-Type: text/plain; charset=utf-8; format=flowed
I was referred to this group by dave.g4ugm at gmail.com who thought you
might be able to help me.
I need to punch a half-dozen datacards for an award for a retired
IBMer. Anyone know where I can find a working 026/029/129 within 300
miles of Raleigh, NC?
Many thanks for any pointers.
Chip Davis
chip at aresti.com
+1.919.271.2582
Tried the ADM-3A out today on my PDP-8/A via the 20 ma current loop
interface - just unplugged the ASR-33 and plugged in the glass TTY :)
Worked great (the current loop probably had never been used, so no one had a
chance to blow it up), but I got tired of holding down the Shift key since
OS/8 doesn't understand lower case letters.
So I decided to set its switch to upper case only... terminal kept putting
out lower case.
Sure enough, that switch contact was stuck closed. It'd probably never been
moved since the terminal was new!
Now waiting on a 6-position dip switch from Mouser. And some 8-position
Mate-n-Lok connectors.
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Hi,
I?m doing some work for a friend who has one of these unicorns it?s apparently a super beefed up CIA use the laptop that wound up in Russia somehow and he got it shipped back here to the US
The motherboard was modified it looks like the hard drive was on some kind of a tray going to a connector which is IDE compatible
Someone had extremely poorly soldered on an IDE cable in place of the sled and over the years several of the pans of popped off and they?re not really making sense as to the solder points they?re supposed to go to. Complicating the matter is the paint outs are not just a direct staggered 40 Pin to Pin connection several of the through holes are not in use so just soldering on I had her and plug in the cable into it is not possible also the pens are staggered so that wouldn?t make it possible either.
So to cut to the chase does anyone have the schematics or the motherboard pinouts for this connector so that I can do a proper soldering job and put on a clean working cable so that this laptop can vote from the IDE hard drive?
Someone on this list, I don't remember who, asked me if I was interested
in this, and then dropped it off. I've not gotten around to doing
anything with it, and I could use the space back. If anyone is
interested, holler.
HP 2250 Measurement & Control Processor
Pictures are the same ones that came with it. Photographer unknown.
https://photos.app.goo.gl/XjEj8E8vQ8KX9xcg8
If your interested in picking it up, email me directly, please. If you
have more information to share, respond to the list. :)
If anyone knows more about what this is, I'd be interested to hear.
I got these links from Mike on the SIMH list:
http://www.hpmuseum.net/display_item.php?hw=986http://www.hpmuseum.net/document.php?hwfile=5124http://www.hpmuseum.net/document.php?hwfile=4579
Mine is the "2250M" version. Apparently this heavy beast is "mobile"
because it has wheels on it. :)
>I've never heard of people using DB25 for 20mA, at least historically,
contemporaneous with its widespread actual use. E.g. DEC universally used
'flat' 8-pin Mate-n-Lok connectors for 20mA serial connections.
Thanks for the comments... I asked mostly because the ADM-3A has both RS-232
and current loop interfaces built-in (on the same female DB-25), selected by
one of the
DIP switches.
I just hate having to make a custom cable for every terminal and computer I
own or work with ;)
-Charles
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> From: Steven M Jones
> imagine that a law is passed in a far away land, and the site owner
> decides it's is too risky to bother with, and they then take the entire
> site down - wiki and fora - with no warning and no access to the
> material...
> ..
> I would strongly suggest that if people are going to do something of
> the scale you describe, they might want to consider setting up a
> distribution or replication mechanism
Past events have made me very concerned about this issue! On a couple of
occasions, Tore (who runs the CHWiki) has forgotten to pay the DNS fee, or
something similar, and it went off-line (the first time for a week, as he
was off camping). Leading to total panic on my part when he wasn't reachable,
about all the content I'd written!
There is an automatic backup system which sends copies to a machine at his
house, so the particular scenario above (hosting sevice goes away with no
warning) is not an issue. (Yes, a Chicxulub event in Scandanavia would defeat
that, but we'd all probably have larger problems to worry about!) After the
first event, I make manual backups here of all the articles I contribute.
The biggest concern is if he has an unfortunate interaction with a truck. I
did raise this issue with him, and he had some initial suggestions, but I
haven't followed through. If people start contributing, it'd probably be time
to formalize something.
Noel
> From: Charles Morris
> Is there any standard pinout for 20 ma current loop using a DB-25
> connector, analogous to the well-documents RS-232 serial interface?
> ...
> Or would you recommend I use a different connector entirely? .. Maybe a
> Jones 4-pin would make more sense.
I've never heard of people using DB25 for 20mA, at least historically,
contemporaneous with its widespread actual use. E.g. DEC universally used
'flat' 8-pin Mate-n-Lok connectors for 20mA serial connections.
Although I have the part numbers for both the male and female 8-pin shells,
they are no longer in production, and are getting hard to find.
Nothing precludes us from establishing a spec for 20mA via a DB25, of course
- especially if a set of pins can be found whih will not cause damage if such
a connector is plugged into an EIA connector by accident.
As 'idiot proof' engineering, I'd be inclined to use some other connector (no
suggestion from me as to what), but I can understand that people might prefer
to use DB25 (which everyone has, and are easy to find).
Noel
Hi,
I have four binders, pictured here: https://imgur.com/a/w9a3YEY
* Reference Manual, AA-K079E-TE
* Guide to Writing Reports, AA-P862C-TE
* Handbook, AA-W675B-TE
* User's Guide, AA-K080E-TE
Did not see scans on bitsavers but it's possible I just overlooked them.
Is there any interest in getting them scanned? I have a suitable scanner.
I can also ship them (from Toronto, Canada) to anyone keen enough to pay
shipping.
--Toby
> From: Seth J. Morabito
>> having stuff scattered across a zillion personal pages (be they blogs,
>> or whatever) is going to make it hard to find the useful one when
>> needed
> The sheer vastness of content available, combined with a Google
> monoculture, combined with a concerted attempt to GAME the Google
> monoculture, is making search and discovery hard
An additional issue, I think, is that Google is deprecating sites that use
HTTP, versus HTTPS. I can't comment more, lest I start ranting at the utter
stupidity of forcing everyone to use HTTPS. But if those blogs are using
HTTP, that will push them down the results.
> I honestly don't know what to do about it. I don't have a better idea,
> unless we go back to something like a directory-style curated
> experience, a-la Yahoo! circa 1998-ish.
I'm not sure that would scale to cover detailed pages on obsolete computers;
why is a manual indexer going to cover them?
Anyway, the whole 'how do we find the info' is a part of why I started
working on CHWiki, once I discovered it - in addition to the usual advantages
of wikis (good for collaboration, good for adding stuff incrementally), it
would put all the info in one place, a 'one stop shopping' for old computer
info.
But when I tried to convince people to post stuff there, instead of on their
blogs, I got at least one person who was pretty vehement that no way in h***
were they going to stop putting their stuff in their own blog.
Noel
