Date   

Re: Fix or Part Out a Tek 475A

 

On Wed, Nov 25, 2020 at 01:44 AM, David Collier wrote:


Hi all,
Just acquired a 475A via eBay.
All seems to work except the trigger source switch which may just need
adjustment/contact cleaning.
Someone already replaced CR1462 with a larger diode bridge, and the fan motor
is noisy.
However, I need replacement knobs for A & B trigger slope (the outer grey
ones). Can anyone help with these?
I notice the trace is not as fine as that on my trusty HP1740A: maybe the EHT
is too low?
To me, your issue seems an excellent candidate for a new topic, unless you consider parting out your 475A, which I'd recommend against...

One important cause of the trace on the Tek 475A being not as fine as that on the HP 1740A is the fact that the 475A, having a 250 MHz bandwidth, shows more noise in the trace. BTW, early 465's (100 MHz, like the 1740A) had a moire noisy trace than later ones.

Raymond


Re: Fix or Part Out a Tek 475A

Tom Lee
 

Congrats on the new scope -- I'm sure you'll enjoy it greatly!

As to trace sharpness, the 465/475 series jugs are sort of infamous for not having the smallest spot size. The expansion mesh gets a lot of blame on the web, but that can't be the whole explanation, as there are many crts with expansion meshes that have smaller spot sizes.

Without seeing your scope's trace with my own eyes (photos tend not to have sufficient fidelity to diagnose this at all well), it's hard to say whether what you're seeing is abnormal. But if it's good and bright, it's unlikely to be an EHT problem.

--Cheers,
Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 11/24/2020 16:44, David Collier wrote:
Hi all,
Just acquired a 475A via eBay.
All seems to work except the trigger source switch which may just need adjustment/contact cleaning.
Someone already replaced CR1462 with a larger diode bridge, and the fan motor is noisy.
However, I need replacement knobs for A & B trigger slope (the outer grey ones). Can anyone help with these?
I notice the trace is not as fine as that on my trusty HP1740A: maybe the EHT is too low?
Regards,
David Collier
Canberra




Re: Fix or Part Out a Tek 475A

 

Hi all,
Just acquired a 475A via eBay.
All seems to work except the trigger source switch which may just need adjustment/contact cleaning.
Someone already replaced CR1462 with a larger diode bridge, and the fan motor is noisy.
However, I need replacement knobs for A & B trigger slope (the outer grey ones). Can anyone help with these?
I notice the trace is not as fine as that on my trusty HP1740A: maybe the EHT is too low?
Regards,
David Collier
Canberra


Re: 2710 Spectrum Analyser 'Cannot count VCO, IF' error

WB6GHK
 

Hi guys, 2710's, oh what fun!

For the "Cannot count VCO, IF" I have found that the majority of the time the 100 MHz timebase module has failed or degraded. The absolute quickest way to determine if it has failed is to sub in a know good working one. It will save you hours of troubleshooting. Find a friend with a later B02xxxx 2710 and beg, steal or borrow the timebase.

Martin, I'm going to assume you have a 2710 service if you troubleshot the power supply, so locate the corresponding pages for the 100MHz timebase and look at the signals coming from the four outputs (I think it's four, going by memory). Scope them to see what is there advise.

I hate to tell you this but B013xxx and below 2710's using the CFCS are not reliable (memory & PS) or accurate (drift), in comparison to later units. Not saying that it isn't worth the time since there is a learning curve and the early 2710 will certainly give you that experience, but the once the unit is operational you may be disappointed.

Best of luck!


Re: 2710 Spectrum Analyser 'Cannot count VCO, IF' error

Martin Whybrow
 

I've done some probing and have identified a problem; note that mine is a post B010318 model, so it has the CFCS rather than the CFC board.
I have a very low signal level at J130 on the Phaselock Assembly (beat frequency output to the counter); the manual indicates this should be TTL, but it's about 100mV peak to peak. All of the supply lines are in limits, but I'm not seeing any signal gain between J110 (Phase/ Beat signal input) and the output of U720, with ~150mV p-p signal levels at each stage.
I have noted that there are some mods to the board and I'm not sure if thas has any bearing on it, I spotted that C742 and C747 have been removed and a through hole 220nF fitted instead, so this may be a repair to deal with a damaged track.
If anyone's familiar with this assy, I would appreciate your suggestions.


Re: LAST CALL for Peter Keller's Book and Current Orders I have

 

Same thing I've been asking myself. Was busy with health. Came back today
to this :) At least some other people will have a fun book to read. Have
fun!

On Tue, Nov 24, 2020 at 10:52 PM David Kuhn <Daveyk021@gmail.com> wrote:

I missed out on this; didn't see it. Too Late?

On Thu, Nov 19, 2020 at 5:24 PM Dennis Tillman W7pF <dennis@ridesoft.com>
wrote:

This is a last call for Peter Keller's fabulous book. I will accept
orders
until Friday evening my time. At present I have orders for 75 books.
At that time I will publish the final list of people I have received an
order from and I will explain how to make payment.
Below are the people who have been placed on Peter's book order. Please
confirm your name is on this list.

If you have missed all of the excitement here is a summary
Pete Keller (from Tektronix) is prolific writer about cathode ray tubes
and
many other kinds of display technologies.
He published a very detailed book on the subject in 1991 which I highly
recommend. The book title is:
"The Cathode Ray Tube, Technology, History, and Applications", Peter A.
Keller. 320 p.
ISBN 0-9631559-0-3;
TK7871.73.K46;
621.3815'42-DC20

I paid $70 for my copy years ago when I bought it from Peter. There is a
copy of his book currently on eBay listed for $650!!!
Peter's book is still available in hard cover and he has copies of it to
sell to us.
Because of recent interest in it from TekScopes members I went out on a
limb
and asked Peter if a discount would be available for our members if we
bought enough books to make it worth his while and if I did all the work
for
him.
He agreed and offered our members a huge discount. The cost will be $30 +
shipping.
I am hoping I can even get him to autograph each copy.
I promised Peter I would keep his effort to an absolute minimum by
collecting the names and addresses, payments which I would send to him in
one lump sum; then when he ships all the books to me I will mail each
book
for him.

The cost for a book going anywhere in the US is $30 + $4 Media Rate
Postage
+ $3 for supplies and my time. The total will be $37.00.
The cost for orders overseas will be $30 + approximately $35 for Flat
Rate
International Priority Mail (this includes tracking).

If you want a copy of Peter's book send your mailing address to me
OFF-LIST
at dennis at ridesoft dot com. INCLUDE YOUR ADDRESS.

These are the orders I have as of 2:15PM (UTC-08:00) Coordinated
Universal
Time-08.
If your name is not on this list then I missed your order (my apologies)
so
resend it with your address.

UNITED STATES ORDERS
Eric Spendel Fairfield, OH 45014
Dave Daniel Mims, FL 32754
Chuck Azzalina Perkasie, PA 18944
Jean Paul Novato, CA 94947
Kurt Rosenfeld Ossining, NY 10562
Vince Vielhaber K8ZW Oxford, MI 48371
Stan Perkins N6BYU San Diego, CA 92109-2348
Bruce Lane Kent, WA 98030-8803
Mark Huffstutter Seattle, WA 98115
Joe Rigdon Oviedo, FL 32765
Jeffrey S. Dutky Silver Spring, MD 20901
Larry Snyder Springboro, OH 45066-9761
Byron Hayes Jr. WA6ATN Toluca Lake, CA 91602-2914
Michael Drum Fanwood, NJ 07023-1008
Jack Reynolds Howell, MI, 48843
Phil Erickson Clinton, MA 01510
Edward Oscarson New Hartford, CT 06057
Steve Berg Casselberry, FL 32707
Charles Daves Aurora, CO 80015-1422
Chuck Harris Damascus, MD 20872
John Malec IV Northglenn, CO 80234
Marvin Moss Marietta, GA 30064
Tom Norman Escalon, CA 95320
Bill Lavick WA2SMF Edwards, NY 13635
Jeff Frantzen Olathe, KS 66062-3693
Glenn Little Goose Creek, SC 29445
Mark Vincent N. Chesterfield, VA 23236
Lance Lieberman Albertson, NY 11507-1022
Steven Horii Bryn Mawr, PA 19010-1226
Charles Nalley Burien, WA 98166
Carl Miles Rio Rancho, NM 87124
Larry Schneider Otis, ME 04605-7652
Dennis McCreery Bellevue, WA 98008
Tim Laing Lima, OH 45801-4644
Chris Wilkson Detroit, MI 48206
Timothy Koeth Brandywine, MD 20613
John Griessen Albuquerque, NM 87107
Greg Muir Great Falls, MT 59405-3144
Kurt Swanson Wilton, CA 95693-9765
Bruce Gentry KA2IVY Mattydale, NY 13211
Peter Brown Broomfield, CO 80023
Tim Pierce Cottage Grove, OR 97424
Bob Darlington N3XKB Los Alamos, NM 87544
Hugh Vartanian Littleton, MA 01460
Richard Brittingham W4MCD Edenton, NC 27932
Jim Rawlings AF6VF Livermore, CA 94550
Monte Meredith Reno, NV 89511
Chris Loggans Haymarket, VA 20169
Steve Bates Concord, MA 01742
John Glass, O'Brien Electric Dallas, OR 97338

INTERNATIONAL ORDERS
Sigurdur Asgeirsson CANADA
Shaun Merrigan CANADA
Bill Perkins, PEARL, Inc. CANADA
Dan Gajanovic CANADA
Andy Guelzow VA7NNM CANADA
Simon Jarman FRANCE
Christoph F. Bruggaier GERMANY
Heinz Breuer GERMANY
Jan Wuesten GERMANY
Red Dot Finder THE NETHERLANDS
Leo Potjewijd THE NETHERLANDS
Mario Giganti I1CWZ ITALY
Colin Herbert UNITED KINGDOM
Alan Ainslie UNITED KINGDOM
Robert Angell UNITED KINGDOM
Thomas S. Knutsen NORWAY
Jared Cabot JAPAN
Gangyi, Le SINGAPORE










Re: 475A man and schems

Roy Thistle
 

On Sun, Nov 22, 2020 at 01:51 PM, Jeff Dutky wrote:


Here is the 475 (and 475A) page: https://w140.com/tekwiki/wiki/475
and here is the service manual PDF:
https://w140.com/tekwiki/images/6/62/070-2162-00.pdf
Hi Jeff:
Yes, you are correct.
I wasn't able to resolve the link's address yesterday (I got repeated D.N.S. errors) but yes it loads for me now.
I see that indeed there are no outlines or drawings of the 475A boards, or 475A schematics, in that file.
Thank you for the posting the link.
Best regards.
Roy


Re: Fix or Part Out a Tek 475A

Dave Peterson
 

Hey Jeff,

I was just writing you a reply. We are in sync here! I was just going to share that despite my brave talk this morning, I'm chickening out and not going any further.

I too had some sketchy looking (to me) stuff going on, but now that I've taken a close look I think it's not worth the effort to tear down the transformer and HV wiring that'd be required to get A9 out.

Glad to hear you cleared up the resistor/schematic discrepancy. That's really frustrating when what's in front of you doesn't match the documentation! Documentation bugs are the worst!

Dave


Re: 475A man and schems

Roy Thistle
 

On Tue, Nov 24, 2020 at 11:28 AM, Colin Herbert wrote:


I can see the 475A Service Manual
Hi Colin:
Yes.
When I search for "475A" at TekWiki at:
http://w140.com/tekwiki/wiki/Main_Page
the following page comes up:
http://w140.com/tekwiki/wiki/475
At the right are links (in blue) for the various files associated with the page.
The file that I should open is "Tektronix 475A Manual", 070-2162-00? ... which indicates... when opened... that it actually is the "475 service manual."
Generally, things are organized, and labelled so, on TekWiki, according to "manual", and "service manual"... so unless someone knew... or opened all the 475A files... they/me would think that is another version of the "user" or "operators" guide?
Indeed, it's there.... thus, if one is following the "Fix or Part Out a Tek 475A " thread... why is there any confusion between which parts are in the Z-axis amplifier of a 475A, versus a 475... as the OP of that thread (et. al.) seem to be following a 475 service manual?... at least part of the time. TekWiki for the docs was mentioned several times in the thread.


Re: 7A26 no signal

 

On Tue, Nov 24, 2020 at 11:16 PM, Jeff Dutky wrote:


(I assume that there are extension plugins that let you run a plugin outside
the main housing, though I can't find reference to such a thing on TekWiki).
Fixed extender: https://w140.com/tekwiki/wiki/067-0589-00.
Flexible extender: https://w140.com/tekwiki/wiki/067-0616-00

Raymond


Re: Fix or Part Out a Tek 475A

 

Simon,

I had a second look at the vertically mounted resistors and I misread the color codes (I read purple as blue), they are marked as 7.5K Ohm, just as the schematics indicate. The resistors still read well out of spec, but this eliminates a big part of the mystery and frustration. The resistors being well out of spec may still be a problem, but at least it looks like I can rely on the schematics.

Also, looking at the board after a night's sleep, I agree that it doesn't look nearly as dire as I was thinking it was.

-- Jeff Dutky


Re: 7A26 no signal

 

Do you have a service manual for the 7A26? If not, here are PDFs of the manuals http://w140.com/tekwiki/wiki/7A26

Looking at the images of the 7A26's insides it should be easy to trace an input signal from the attenuators through the amplification stages and then to the backplane, assuming that you can connect the module to the backplane in a way that allows you to access the insides (I assume that there are extension plugins that let you run a plugin outside the main housing, though I can't find reference to such a thing on TekWiki).

I did something similar with a 475 a few weeks ago, and tracing the signal was quite simple to do, given schematics and board layouts, and a second scope to test with. In my case the issue was an unseated channel switch IC, and tracing the signal through channel 1 lead me straight to the problem.

Looking at the images it doesn't look like the 7A26 has the channel switch that the vertical system of a 475 has (I assume that's located in main unit), which means that the common failure must be elsewhere. The obvious places to look are where the signals exit the plugin, and where power enters the plugin, but you really need to see how far the input signal gets through the amplification chain to make any real diagnosis.


Re: OCP5502 Optical Power Meter Temperature control fault

Dave Wright
 

Some new information...

The failure code upon a ZERO operation is 2434, which the manual describes as "O/E closed loop zero high (possible defective measurement board)"

The response to the GPIB TEMP? command is -1, which means cold.
From the manual: "The TEMP? command returns the status of the temperature controller on the OCP photodiode. If the controller is functioning properly, a 0 is returned. If the photodiode is too hot, a 1 is returned and a 6020 event is generated. If the diode is too cold, a -1 is returned and a 6021 event generated."

So, this leads me to believe that the temperature sensor, or the conditioning electronics are at fault, and the control loop is asking for heat. The heater and its drive are certainly working, evidenced by the smell and smoke...

I suspect the sensor, thermistor or whatever, is inside the optical module in thermal contact with the photo-diode. If that has failed, I am probably out of luck...

However, if the feedback amplifier is where the problem is, there may be hope as there is an area of the PCB labelled HEATER CONTROL, a likely spot for more investigation...

_Dave KC6UPS


Re: LAST CALL for Peter Keller's Book and Current Orders I have

David Kuhn
 

I missed out on this; didn't see it. Too Late?

On Thu, Nov 19, 2020 at 5:24 PM Dennis Tillman W7pF <dennis@ridesoft.com>
wrote:

This is a last call for Peter Keller's fabulous book. I will accept orders
until Friday evening my time. At present I have orders for 75 books.
At that time I will publish the final list of people I have received an
order from and I will explain how to make payment.
Below are the people who have been placed on Peter's book order. Please
confirm your name is on this list.

If you have missed all of the excitement here is a summary
Pete Keller (from Tektronix) is prolific writer about cathode ray tubes and
many other kinds of display technologies.
He published a very detailed book on the subject in 1991 which I highly
recommend. The book title is:
"The Cathode Ray Tube, Technology, History, and Applications", Peter A.
Keller. 320 p.
ISBN 0-9631559-0-3;
TK7871.73.K46;
621.3815'42-DC20

I paid $70 for my copy years ago when I bought it from Peter. There is a
copy of his book currently on eBay listed for $650!!!
Peter's book is still available in hard cover and he has copies of it to
sell to us.
Because of recent interest in it from TekScopes members I went out on a
limb
and asked Peter if a discount would be available for our members if we
bought enough books to make it worth his while and if I did all the work
for
him.
He agreed and offered our members a huge discount. The cost will be $30 +
shipping.
I am hoping I can even get him to autograph each copy.
I promised Peter I would keep his effort to an absolute minimum by
collecting the names and addresses, payments which I would send to him in
one lump sum; then when he ships all the books to me I will mail each book
for him.

The cost for a book going anywhere in the US is $30 + $4 Media Rate Postage
+ $3 for supplies and my time. The total will be $37.00.
The cost for orders overseas will be $30 + approximately $35 for Flat Rate
International Priority Mail (this includes tracking).

If you want a copy of Peter's book send your mailing address to me OFF-LIST
at dennis at ridesoft dot com. INCLUDE YOUR ADDRESS.

These are the orders I have as of 2:15PM (UTC-08:00) Coordinated Universal
Time-08.
If your name is not on this list then I missed your order (my apologies)
so
resend it with your address.

UNITED STATES ORDERS
Eric Spendel Fairfield, OH 45014
Dave Daniel Mims, FL 32754
Chuck Azzalina Perkasie, PA 18944
Jean Paul Novato, CA 94947
Kurt Rosenfeld Ossining, NY 10562
Vince Vielhaber K8ZW Oxford, MI 48371
Stan Perkins N6BYU San Diego, CA 92109-2348
Bruce Lane Kent, WA 98030-8803
Mark Huffstutter Seattle, WA 98115
Joe Rigdon Oviedo, FL 32765
Jeffrey S. Dutky Silver Spring, MD 20901
Larry Snyder Springboro, OH 45066-9761
Byron Hayes Jr. WA6ATN Toluca Lake, CA 91602-2914
Michael Drum Fanwood, NJ 07023-1008
Jack Reynolds Howell, MI, 48843
Phil Erickson Clinton, MA 01510
Edward Oscarson New Hartford, CT 06057
Steve Berg Casselberry, FL 32707
Charles Daves Aurora, CO 80015-1422
Chuck Harris Damascus, MD 20872
John Malec IV Northglenn, CO 80234
Marvin Moss Marietta, GA 30064
Tom Norman Escalon, CA 95320
Bill Lavick WA2SMF Edwards, NY 13635
Jeff Frantzen Olathe, KS 66062-3693
Glenn Little Goose Creek, SC 29445
Mark Vincent N. Chesterfield, VA 23236
Lance Lieberman Albertson, NY 11507-1022
Steven Horii Bryn Mawr, PA 19010-1226
Charles Nalley Burien, WA 98166
Carl Miles Rio Rancho, NM 87124
Larry Schneider Otis, ME 04605-7652
Dennis McCreery Bellevue, WA 98008
Tim Laing Lima, OH 45801-4644
Chris Wilkson Detroit, MI 48206
Timothy Koeth Brandywine, MD 20613
John Griessen Albuquerque, NM 87107
Greg Muir Great Falls, MT 59405-3144
Kurt Swanson Wilton, CA 95693-9765
Bruce Gentry KA2IVY Mattydale, NY 13211
Peter Brown Broomfield, CO 80023
Tim Pierce Cottage Grove, OR 97424
Bob Darlington N3XKB Los Alamos, NM 87544
Hugh Vartanian Littleton, MA 01460
Richard Brittingham W4MCD Edenton, NC 27932
Jim Rawlings AF6VF Livermore, CA 94550
Monte Meredith Reno, NV 89511
Chris Loggans Haymarket, VA 20169
Steve Bates Concord, MA 01742
John Glass, O'Brien Electric Dallas, OR 97338

INTERNATIONAL ORDERS
Sigurdur Asgeirsson CANADA
Shaun Merrigan CANADA
Bill Perkins, PEARL, Inc. CANADA
Dan Gajanovic CANADA
Andy Guelzow VA7NNM CANADA
Simon Jarman FRANCE
Christoph F. Bruggaier GERMANY
Heinz Breuer GERMANY
Jan Wuesten GERMANY
Red Dot Finder THE NETHERLANDS
Leo Potjewijd THE NETHERLANDS
Mario Giganti I1CWZ ITALY
Colin Herbert UNITED KINGDOM
Alan Ainslie UNITED KINGDOM
Robert Angell UNITED KINGDOM
Thomas S. Knutsen NORWAY
Jared Cabot JAPAN
Gangyi, Le SINGAPORE






PayPal Friends and Family Peter Keller CRT Book

Tim Laing
 

I have had PayPal for many years and it has gotten a lot of use for both buying and selling. Mostly buying the last few years. Also many years ago I did a group buy for over 1000 Nixie tubes that I then shipped all over the world to many purchasers. So I know what Dennis is going through! At least he is not shipping glass tubes! On a side note not one got broken!
Well back to PayPal, on the iPhone PayPal app the friends and family option is available. Also using friends and family you have several options for payment source ( if you have them set up.). In my case PayPal balance(in my case $0.00 as I am not selling) credit card(yes I have one linked) or linked bank account. I think I had to link a bank account to sell many years back. So the credit card option has a PayPal fee to the purchaser even for friends and family. There are no PayPal fees for using your PayPal cash balance for friends and family. There are no fees for using your linked bank account for friends and family. I have a free credit union account that pretty much only gets used for PayPal. I transfer money into this account when I have a paypal transaction coming up. Then I select linked bank account when I go to pay. No fees incurred to either party. These are all for domestic transactions.
All of the above is done online. Tim Laing


Re: (OT) Where to go for 70s IBM hardware? I'm looking for a terminal.

Geoffrey Thomas
 

Hi,
Have you tried ClassicCmp?

http://classiccmp.org/

Seems to be a real hive of info of the sort you're looking for.

Geoff.

On 24/11/2020 15:42, cheater cheater wrote:
Hi all,
sorry for the offtopic message, not sure where to go with this one, so I thought the smart heads around here might be connected somewhere. I'm looking to get a 70s IBM terminal, either for a System/3, /6, /32, /38 (or contemporary), 3600 FCS, a Display Station (or terminal) for the IBM 32xx, 37xx, 49xx, 52xx, 65xx, or 74xx, or an IBM 5100/5110/5120 portable computer. I'm interested to see how they were built and would like to see how it is to use them. If you know any good places to go other than the website which should not be named, especially any forums that could have enthusiasts of the same hardware, or if you know someone willing to part with one such machine, let me know please.
Thanks!


Re: (OT) Where to go for 70s IBM hardware? I'm looking for a terminal.

Dave Daniel
 

Where are you located?

DaveD

On Nov 24, 2020, at 15:00, cheater cheater <cheater00social@gmail.com> wrote:

If anyone has a friend who might have one of those, or may have worked with
them, would you mind reaching out to them and asking around? I'll make sure
to make it worth everyone's time. I just want to help preserve some of this
tech for the future and describe what it does and how, before it is
irreversibly committed to obscurity.

On Tue, Nov 24, 2020 at 8:03 PM cheater cheater via groups.io
<cheater00social=gmail.com@groups.io> wrote:

Thanks everyone. Not really bothered about the dependency on a control
unit for two reasons. First of all, finding /anything/ of this era will be
difficult, whether it's the rarer RS232 kind, or less rare control unit
based type. Second of all, emulating the bus will likely be part of an
interesting challenge and a good way of figuring out the inner workings of
the display and input device, which is what I want to do, so rather than a
problem it's a positive thing for me. A $10 computer nowadays will be able
to do the job. My current biggest problem is locating those older terminals
in the first place. My assumption is they're mostly in defunct computer
graveyards, warehouses, university store rooms, or bank or utilities store
rooms, dusting and decaying away.









Re: (OT) Where to go for 70s IBM hardware? I'm looking for a terminal.

Paul Amaranth
 

One of my first jobs was writing CICS code that drove 3270s. Cutting edge
at the time but, truthfully? I don't mind it going obscure :-)

Now that I think of it, there's quite a lot of similarity between that and
writing systems using browsers as their interface.

Best of luck on your search; somebody needs to have a *very* dusty closet.

Paul

On Tue, Nov 24, 2020 at 09:00:58PM +0100, cheater cheater wrote:
If anyone has a friend who might have one of those, or may have worked with
them, would you mind reaching out to them and asking around? I'll make sure
to make it worth everyone's time. I just want to help preserve some of this
tech for the future and describe what it does and how, before it is
irreversibly committed to obscurity.
--
Paul Amaranth, GCIH | Manchester MI, USA
Aurora Group of Michigan, LLC | Security, Systems & Software
paul@AuroraGrp.Com | Unix/Linux - We don't do windows


Re: (OT) Where to go for 70s IBM hardware? I'm looking for a terminal.

 

Thanks... two people who suggested Curious Marc by now...

On Tue, Nov 24, 2020 at 9:17 PM Eric <ericsp@gmail.com> wrote:

I would suggest Curious Marc's you tube channel and the living computer
museum he is a part of. They have some very early stuff including a
functioning PDP1.

Eric

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of cheater
cheater
Sent: Tuesday, November 24, 2020 3:01 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] (OT) Where to go for 70s IBM hardware? I'm
looking for a terminal.

If anyone has a friend who might have one of those, or may have worked
with them, would you mind reaching out to them and asking around? I'll make
sure to make it worth everyone's time. I just want to help preserve some of
this tech for the future and describe what it does and how, before it is
irreversibly committed to obscurity.

On Tue, Nov 24, 2020 at 8:03 PM cheater cheater via groups.io
<cheater00social=gmail.com@groups.io> wrote:

Thanks everyone. Not really bothered about the dependency on a control
unit for two reasons. First of all, finding /anything/ of this era
will be difficult, whether it's the rarer RS232 kind, or less rare
control unit based type. Second of all, emulating the bus will likely
be part of an interesting challenge and a good way of figuring out the
inner workings of the display and input device, which is what I want
to do, so rather than a problem it's a positive thing for me. A $10
computer nowadays will be able to do the job. My current biggest
problem is locating those older terminals in the first place. My
assumption is they're mostly in defunct computer graveyards,
warehouses, university store rooms, or bank or utilities store rooms,
dusting and decaying away.
















Re: (OT) Where to go for 70s IBM hardware? I'm looking for a terminal.

Eric
 

I would suggest Curious Marc's you tube channel and the living computer museum he is a part of. They have some very early stuff including a functioning PDP1.

Eric

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of cheater cheater
Sent: Tuesday, November 24, 2020 3:01 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] (OT) Where to go for 70s IBM hardware? I'm looking for a terminal.

If anyone has a friend who might have one of those, or may have worked with them, would you mind reaching out to them and asking around? I'll make sure to make it worth everyone's time. I just want to help preserve some of this tech for the future and describe what it does and how, before it is irreversibly committed to obscurity.

On Tue, Nov 24, 2020 at 8:03 PM cheater cheater via groups.io <cheater00social=gmail.com@groups.io> wrote:

Thanks everyone. Not really bothered about the dependency on a control
unit for two reasons. First of all, finding /anything/ of this era
will be difficult, whether it's the rarer RS232 kind, or less rare
control unit based type. Second of all, emulating the bus will likely
be part of an interesting challenge and a good way of figuring out the
inner workings of the display and input device, which is what I want
to do, so rather than a problem it's a positive thing for me. A $10
computer nowadays will be able to do the job. My current biggest
problem is locating those older terminals in the first place. My
assumption is they're mostly in defunct computer graveyards,
warehouses, university store rooms, or bank or utilities store rooms, dusting and decaying away.





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