On 2012-02-14, wrote:
On Mon, 13 Feb 2012 20:46:45 -0600, "Snag" wrote:

[ ... ]

You owe me a keyboard . The old one quit after I spewed beer all over it .
Shoulda swallowed before I clicked ...

Best way to remove beer from a keyboard is with copious application of
isopropyl alcohol followed by compressed air under moderate pressure,
repeated several times.

Put the keyboard on the Xerox (or other photocopy) machine first,
because compressed air is likely to pop the keycaps off the keys, and
you want to have the full layout in front of you before you start
sticking them back on. Yes, the letters are pretty predictable if you
start at the right place, but function keys and even things like
"Control" and "Caps Lock" migrate between keyboards, let alone things
like '~'.

If it is a cordless keyboard, don't forget to
either take the battery out or turn off the computer before you start
DAMHIKT.

Absolutely! The first step when a spill gets into a keyboard or
something similar is to remove *all* sources of power.

Simpler solution is to open the wallet.

I had a keyboard (originally from a Tektronix Silent-700
terminal, and acquired from a hamfest) which got urinated on by a pet
squirrel. The solution there was to run it under the shower in the tub
for a while, then stand it on edge for a couple of days, but that was
built differently from the current run of keyboards. The squirrel
finally decided that outdoors was where he wanted to be. :-)

For the Sun keyboards which I like, every once in a while too
much cat hair gets in and first starts padding the keys so you have to
hit them a little harder. Then later, it works between the layers of
flexible printed circuit boards (all on transparent mylar or the like).
The first and third layers have crossover areas which when pushed
together conduct. The middle layer has a series of holes under the
keys, so it holds the first and third layers apart until you get enough
pressure to bend the layers together. The keycaps have little rubber
falsies to hold them up and serve as springs.

For these, a full disassembly is necessary -- the keycaps in a
container, the layer of falsies (some versions are individual, others
are a sheet of falsies in the right positions) needs to be hit with
compressed air to carry off the cat hair there. The top plate needs it
as well, to get the hair out of the key guides, then the individual
layers go down to the shop and are individually hit with compressed air
to carry off the cat hair, Then it all goes back upstairs and gets
reassembled and is good for a few more years.

If beer is involved. each layer needs to be washed by
clean water first, then dried with compressed air and reassembled.

Enjoy,
DoN.

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--- Black Holes are where God is dividing by zero ---

"DoN. Nichols" wrote:


I had a keyboard (originally from a Tektronix Silent-700 terminal


Texas Instruments made the Silent-700 line of terminals. I think I
still have one around here.


--
You can't have a sense of humor, if you have no sense.

Ok - I took delivery from dear Dad of my Freshman and Sophomore year in
High School - my 900 gate Game system - plays NIM against you on a light
display (15 bulbs) and a switch button box as the control box. Each
gate is a potted RTL gate that is RAD hard and still works. I'm fixing
it up and checking it out - maybe I can get it into some history place.
Game machine like that in the early 60's.
It was a 3th generation with me. Switches, tubes, RTL logic.

Martin

On 2/15/2012 12:14 AM, Michael A. Terrell wrote:

"DoN. Nichols" wrote:


I had a keyboard (originally from a Tektronix Silent-700 terminal


Texas Instruments made the Silent-700 line of terminals. I think I
still have one around here.

Martin Eastburn wrote:

Ok - I took delivery from dear Dad of my Freshman and Sophomore year in
High School - my 900 gate Game system - plays NIM against you on a light
display (15 bulbs) and a switch button box as the control box. Each
gate is a potted RTL gate that is RAD hard and still works. I'm fixing
it up and checking it out - maybe I can get it into some history place.
Game machine like that in the early 60's.
It was a 3th generation with me. Switches, tubes, RTL logic.


I still have a few new RTL ICs. Some are early flatpak, and were
surplus made for NASA. Others are DIP left over from trying to repair a
Philco Seirra Frequency Selective Voltmeter. I needed two types I never
did find.


--
You can't have a sense of humor, if you have no sense.

On 2/15/2012 11:05 PM, Michael A. Terrell wrote:

Martin Eastburn wrote:

Ok - I took delivery from dear Dad of my Freshman and Sophomore year in
High School - my 900 gate Game system - plays NIM against you on a light
display (15 bulbs) and a switch button box as the control box. Each
gate is a potted RTL gate that is RAD hard and still works. I'm fixing
it up and checking it out - maybe I can get it into some history place.
Game machine like that in the early 60's.
It was a 3th generation with me. Switches, tubes, RTL logic.


I still have a few new RTL ICs. Some are early flatpak, and were
surplus made for NASA. Others are DIP left over from trying to repair a
Philco Seirra Frequency Selective Voltmeter. I needed two types I never
did find.




I remember those days.
I took one look at RTL and RAN to TTL.
And never regretted it.

On 2012-02-15, Michael A. Terrell wrote:

"DoN. Nichols" wrote:


I had a keyboard (originally from a Tektronix Silent-700 terminal


Texas Instruments made the Silent-700 line of terminals. I think I
still have one around here.

You're right. I've been working on some Tektronix 'scopes and
plugins recently, and every time I start to type something electronic
which starts with 'T', it comes out "Tektronix" -- even if it isn't. :-)

And to add to the problems, if I tried to type the abbreviation
of Texas Instruments, my spelling correction would change it to "IT". :-)

Thanks for the correction.
DoN.

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--- Black Holes are where God is dividing by zero ---

On 2012-02-16, Michael A. Terrell wrote:

Martin Eastburn wrote:

Ok - I took delivery from dear Dad of my Freshman and Sophomore year in
High School - my 900 gate Game system - plays NIM against you on a light
display (15 bulbs) and a switch button box as the control box. Each
gate is a potted RTL gate that is RAD hard and still works. I'm fixing
it up and checking it out - maybe I can get it into some history place.
Game machine like that in the early 60's.
It was a 3th generation with me. Switches, tubes, RTL logic.


I still have a few new RTL ICs. Some are early flatpak, and were
surplus made for NASA. Others are DIP left over from trying to repair a
Philco Seirra Frequency Selective Voltmeter. I needed two types I never
did find.

I remember when Popular Electronics gave a NIM playing computer
built purely with rotary switches and lamps. :-)

Enjoy,
DoN.

--
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Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Richard wrote:

I remember those days.
I took one look at RTL and RAN to TTL.
And never regretted it.


I did a lot of work with TTL, but I've used RTL and DTL when I had
to. Then there was NMOS PMOS and finally CMOS which is the most used
right now. There are some interesting Silicon/Germanium high speed
semiconductors being manufactured these days.


--
You can't have a sense of humor, if you have no sense.

"DoN. Nichols" wrote:

On 2012-02-15, Michael A. Terrell wrote:

"DoN. Nichols" wrote:


I had a keyboard (originally from a Tektronix Silent-700 terminal


Texas Instruments made the Silent-700 line of terminals. I think I
still have one around here.

You're right. I've been working on some Tektronix 'scopes and
plugins recently, and every time I start to type something electronic
which starts with 'T', it comes out "Tektronix" -- even if it isn't. :-)

And to add to the problems, if I tried to type the abbreviation
of Texas Instruments, my spelling correction would change it to "IT". :-)

Thanks for the correction.


No problem. I knew that you knew who really made it.


--
You can't have a sense of humor, if you have no sense.

"DoN. Nichols" wrote:

On 2012-02-16, Michael A. Terrell wrote:

Martin Eastburn wrote:

Ok - I took delivery from dear Dad of my Freshman and Sophomore year in
High School - my 900 gate Game system - plays NIM against you on a light
display (15 bulbs) and a switch button box as the control box. Each
gate is a potted RTL gate that is RAD hard and still works. I'm fixing
it up and checking it out - maybe I can get it into some history place.
Game machine like that in the early 60's.
It was a 3th generation with me. Switches, tubes, RTL logic.


I still have a few new RTL ICs. Some are early flatpak, and were
surplus made for NASA. Others are DIP left over from trying to repair a
Philco Seirra Frequency Selective Voltmeter. I needed two types I never
did find.

I remember when Popular Electronics gave a NIM playing computer
built purely with rotary switches and lamps. :-)


How about their 'calculator' built with NE2 ring counters, and
'programmed' with a rotary switch and a telephone dial?


--
You can't have a sense of humor, if you have no sense.

On Wed, 15 Feb 2012 22:35:38 -0600, Martin Eastburn
wrote:

Ok - I took delivery from dear Dad of my Freshman and Sophomore year in
High School - my 900 gate Game system - plays NIM against you on a light
display (15 bulbs) and a switch button box as the control box. Each
gate is a potted RTL gate that is RAD hard and still works. I'm fixing
it up and checking it out - maybe I can get it into some history place.
Game machine like that in the early 60's.

Sounds like a fun project. What's NIM?


It was a 3th generation with me. Switches, tubes, RTL logic.

And, um, what's "threeth"?


--
Fear not those who argue but those who dodge.
-- Marie Ebner von Eschenbach

On 2012-02-16, Michael A. Terrell wrote:

"DoN. Nichols" wrote:

On 2012-02-16, Michael A. Terrell wrote:

[ ... ]

I still have a few new RTL ICs. Some are early flatpak, and were
surplus made for NASA. Others are DIP left over from trying to repair a
Philco Seirra Frequency Selective Voltmeter. I needed two types I never
did find.

I remember when Popular Electronics gave a NIM playing computer
built purely with rotary switches and lamps. :-)


How about their 'calculator' built with NE2 ring counters, and
'programmed' with a rotary switch and a telephone dial?

Hmm ... I seem to have missed that one. Perhaps when I moved
and it was a while before I could find a place to buy new issues?

Any idea when that one appeared? It sounds like fun.

Come to think if it -- with the proliferation of LEDs, does
anyone still make and sell NE2s? Last I've seen them has been in AC
power switches in power fanout boxes for home computers, in generally
blinking or not even that as the lamps age. :-)

Enjoy,
DoN.

--
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Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"DoN. Nichols" wrote:

Michael A. Terrell wrote:

How about their 'calculator' built with NE2 ring counters, and
'programmed' with a rotary switch and a telephone dial?

Hmm ... I seem to have missed that one. Perhaps when I moved
and it was a while before I could find a place to buy new issues?

Any idea when that one appeared? It sounds like fun.


'67 to '70, while I was in high school.


Come to think if it -- with the proliferation of LEDs, does
anyone still make and sell NE2s? Last I've seen them has been in AC
power switches in power fanout boxes for home computers, in generally
blinking or not even that as the lamps age. :-)
\

You can buy bags of 100 on Ebay, and I think Mouser still sells them.


--
You can't have a sense of humor, if you have no sense.

On 2012-02-17, Michael A. Terrell wrote:

"DoN. Nichols" wrote:

Michael A. Terrell wrote:

How about their 'calculator' built with NE2 ring counters, and
'programmed' with a rotary switch and a telephone dial?

Hmm ... I seem to have missed that one. Perhaps when I moved
and it was a while before I could find a place to buy new issues?

Any idea when that one appeared? It sounds like fun.


'67 to '70, while I was in high school.

O.K. I was working by then, in electronics, and did not bother
with Popular Electronics by then. Instead, the industrial mags
available at work were more fun for me -- including the ad for a company
to do assembly work for your company. They pulled the nicest looking
receptionist from the front desk and posed here with a Ungar soldering
iron -- the kind with the screw-in ceramic heating elements. And had
her posed holding it by the ceramic, not the cork grip a little farther
back on the handle. Based on the serenity of her expression, it was
clear that the other end of the iron's cord was *not* plugged in. :-)

Come to think if it -- with the proliferation of LEDs, does
anyone still make and sell NE2s? Last I've seen them has been in AC
power switches in power fanout boxes for home computers, in generally
blinking or not even that as the lamps age. :-)
\

You can buy bags of 100 on Ebay, and I think Mouser still sells them.

Hmm ... 100 of those, and 100 caps and resistors and a diode and
other cap of the right size, and you could have a nice "old computer"
front panel simulator. :-)

Enjoy,
DoN.

--
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Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"DoN. Nichols" wrote:

Michael A. Terrell wrote:

'67 to '70, while I was in high school.

O.K. I was working by then, in electronics, and did not bother
with Popular Electronics by then. Instead, the industrial mags
available at work were more fun for me -- including the ad for a company
to do assembly work for your company. They pulled the nicest looking
receptionist from the front desk and posed here with a Ungar soldering
iron -- the kind with the screw-in ceramic heating elements. And had
her posed holding it by the ceramic, not the cork grip a little farther
back on the handle. Based on the serenity of her expression, it was
clear that the other end of the iron's cord was *not* plugged in. :-)


That, or she really was a blonde. ;-)


You can buy bags of 100 on Ebay, and I think Mouser still sells them.

Hmm ... 100 of those, and 100 caps and resistors and a diode and
other cap of the right size, and you could have a nice "old computer"
front panel simulator. :-)


Orget creative with thin plexiglass and make your own 'Nixie' style
displays y edgeligting the individual layers. ;-)

--
You can't have a sense of humor, if you have no sense.

On 2012-02-18, Michael A. Terrell wrote:

"DoN. Nichols" wrote:

[ ... Ne-2 lamps ... ]

Hmm ... 100 of those, and 100 caps and resistors and a diode and
other cap of the right size, and you could have a nice "old computer"
front panel simulator. :-)


Orget creative with thin plexiglass and make your own 'Nixie' style
displays y edgeligting the individual layers. ;-)

Hmm ... you know that a commercial product had that. The
Non-Linear System's digital voltmeters used a series of stepper motors
to implement a Kelvi-Varley divider. Four digits, IIRC. Really noisy
with the sound-deadening cover off for test or repair. :-)

However -- they needed a lot more illlumination than a NE-2
could create. They used the little flanged incandescent lamps of the
327 series. (I forget what the actual number was. 327 was 28V IIRC,
and 328 was 6V. They were common in aircraft indicators and such.)

Enjoy,
DoN.

--
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Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"DoN. Nichols" wrote:

On 2012-02-18, Michael A. Terrell ? wrote:
?
? "DoN. Nichols" wrote:

[ ... Ne-2 lamps ... ]

?? Hmm ... 100 of those, and 100 caps and resistors and a diode and
?? other cap of the right size, and you could have a nice "old computer"
?? front panel simulator. :-)
?
?
? Orget creative with thin plexiglass and make your own 'Nixie' style
? displays y edgeligting the individual layers. ;-)

Hmm ... you know that a commercial product had that. The
Non-Linear System's digital voltmeters used a series of stepper motors
to implement a Kelvi-Varley divider. Four digits, IIRC. Really noisy
with the sound-deadening cover off for test or repair. :-)


Today, you could use a couple rectangular LEDs per segment. You could
even change the color for out of range conditions.


However -- they needed a lot more illlumination than a NE-2
could create. They used the little flanged incandescent lamps of the
327 series. (I forget what the actual number was. 327 was 28V IIRC,
and 328 was 6V. They were common in aircraft indicators and such.)


And in legended indicator switches. I still have a few of both types
as spares.


--
You can't have a sense of humor, if you have no sense.

On Feb 16, 11:13*pm, "DoN. Nichols" wrote:

* * * * Come to think if it -- with the proliferation of LEDs, does
anyone still make and sell NE2s? *Last I've seen them has been in AC
power switches in power fanout boxes for home computers, in generally
blinking or not even that as the lamps age. :-)

* * * * Enjoy,
* * * * * * * * DoN.

Chicago Miniature
http://www.chml.com/products/pdf/5-4.pdf

Several flavors in stock at Mouser.

Now I have to wonder why it is that whenever I do a new design, at
least one part goes obsolete before the design is finished. But I can
still buy NE2s by the thousands?

On 2012-02-19, Michael A. Terrell wrote:

"DoN. Nichols" wrote:

On 2012-02-18, Michael A. Terrell ? wrote:
?
? "DoN. Nichols" wrote:

[ ... Ne-2 lamps ... ]

[ ... ]

Hmm ... you know that a commercial product had that. The
Non-Linear System's digital voltmeters used a series of stepper motors
to implement a Kelvi-Varley divider. Four digits, IIRC. Really noisy
with the sound-deadening cover off for test or repair. :-)


Today, you could use a couple rectangular LEDs per segment. You could
even change the color for out of range conditions.

Yes, those would be pretty good. Of course, they would be
*much* more expensive to make than the off-the-shelf 7-segment LED
readouts. (There was a *lot* of precision machining in that NLS readout
assembly. :-)

However -- they needed a lot more illumination than a NE-2
could create. They used the little flanged incandescent lamps of the
327 series. (I forget what the actual number was. 327 was 28V IIRC,
and 328 was 6V. They were common in aircraft indicators and such.)


And in legended indicator switches. I still have a few of both types
as spares.

Indeed so, as do I. Lovely little things. What would be nice
would be to get LEDs in the same package -- ideally with a built-in
bridge rectifier to make them happy with AC power. :-) Should last a
*lot* longer than the same lamps in a vibrating environment like an
aircraft cockpit.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"DoN. Nichols" wrote:

On 2012-02-19, Michael A. Terrell wrote:

"DoN. Nichols" wrote:

On 2012-02-18, Michael A. Terrell ? wrote:
?
? "DoN. Nichols" wrote:

[ ... Ne-2 lamps ... ]

[ ... ]

Hmm ... you know that a commercial product had that. The
Non-Linear System's digital voltmeters used a series of stepper motors
to implement a Kelvi-Varley divider. Four digits, IIRC. Really noisy
with the sound-deadening cover off for test or repair. :-)


Today, you could use a couple rectangular LEDs per segment. You could
even change the color for out of range conditions.

Yes, those would be pretty good. Of course, they would be
*much* more expensive to make than the off-the-shelf 7-segment LED
readouts. (There was a *lot* of precision machining in that NLS readout
assembly. :-)


Which would be easy with a CNC machine. Can you imagine the problems
NCR had making their mechanical cash registers without CNC?


However -- they needed a lot more illumination than a NE-2
could create. They used the little flanged incandescent lamps of the
327 series. (I forget what the actual number was. 327 was 28V IIRC,
and 328 was 6V. They were common in aircraft indicators and such.)


And in legended indicator switches. I still have a few of both types
as spares.

Indeed so, as do I. Lovely little things. What would be nice
would be to get LEDs in the same package -- ideally with a built-in
bridge rectifier to make them happy with AC power. :-) Should last a
*lot* longer than the same lamps in a vibrating environment like an
aircraft cockpit.


LED replacements have been available for over 20 years, but they are
even more expensive than the lamps they replace.

--
You can't have a sense of humor, if you have no sense.

On 02/14/2012 10:14 PM, Michael A. Terrell wrote:

"DoN. Nichols" wrote:


I had a keyboard (originally from a Tektronix Silent-700 terminal


Texas Instruments made the Silent-700 line of terminals. I think I
still have one around here.


I have 2 rolls of paper for Silent-700, still in the black
plastic bags.

--
Gary A. Gorgen | "From ideas to PRODUCTS"
| Tunxis Design Inc.
| Cupertino, Ca. 95014

"Gary A. Gorgen" wrote:

On 02/14/2012 10:14 PM, Michael A. Terrell wrote:

"DoN. Nichols" wrote:


I had a keyboard (originally from a Tektronix Silent-700 terminal


Texas Instruments made the Silent-700 line of terminals. I think I
still have one around here.


I have 2 rolls of paper for Silent-700, still in the black
plastic bags.


I had a whole case, but I think it was in the warehouse I lost when I
got sick. I bet someone would buy that paper on Ebay.


--
You can't have a sense of humor, if you have no sense.

On 2012-02-20, Michael A. Terrell wrote:

"DoN. Nichols" wrote:

On 2012-02-19, Michael A. Terrell wrote:

"DoN. Nichols" wrote:

[ ... ]

Non-Linear System's digital voltmeters used a series of stepper motors
to implement a Kelvi-Varley divider. Four digits, IIRC. Really noisy
with the sound-deadening cover off for test or repair. :-)


Today, you could use a couple rectangular LEDs per segment. You could
even change the color for out of range conditions.

Yes, those would be pretty good. Of course, they would be
*much* more expensive to make than the off-the-shelf 7-segment LED
readouts. (There was a *lot* of precision machining in that NLS readout
assembly. :-)


Which would be easy with a CNC machine. Can you imagine the problems
NCR had making their mechanical cash registers without CNC?

Indeed -- lots of custom fixturing. Actually, I think that the
frame for all the Plexiglas (or Lucite) panels was likely made with a
horizontal mill with a stack of cutters on it cutting all the guide
slots in the sides in a single pass, then assembled to make the overall
frame.

[ ... ]

Indeed so, as do I. Lovely little things. What would be nice
would be to get LEDs in the same package -- ideally with a built-in
bridge rectifier to make them happy with AC power. :-) Should last a
*lot* longer than the same lamps in a vibrating environment like an
aircraft cockpit.


LED replacements have been available for over 20 years, but they are
even more expensive than the lamps they replace.

Not when you count the cost of replacing them frequently, or
having a crucial indicator lamp burn out in the cockpit. (Of
course, they typically had two or three lamps per indicator, so you get
some warning when one lamp burns out.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 2012-02-20, Gary A. Gorgen wrote:
On 02/14/2012 10:14 PM, Michael A. Terrell wrote:

"DoN. Nichols" wrote:


I had a keyboard (originally from a Tektronix Silent-700 terminal


Texas Instruments made the Silent-700 line of terminals. I think I
still have one around here.


I have 2 rolls of paper for Silent-700, still in the black
plastic bags.

And what color is the paper by now? :-) Unless it was stored in
a cool environment the whole time, it is likely too dark to use. :-)
After all, the printing was done by flashing it with heat. That is what
made it "silent" compared to the mechanical marvel which was the ASR-33
Teletype. :-)

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"DoN. Nichols" wrote:

On 2012-02-20, Michael A. Terrell wrote:

"DoN. Nichols" wrote:

On 2012-02-19, Michael A. Terrell wrote:

"DoN. Nichols" wrote:

[ ... ]

Non-Linear System's digital voltmeters used a series of stepper motors
to implement a Kelvi-Varley divider. Four digits, IIRC. Really noisy
with the sound-deadening cover off for test or repair. :-)


Today, you could use a couple rectangular LEDs per segment. You could
even change the color for out of range conditions.

Yes, those would be pretty good. Of course, they would be
*much* more expensive to make than the off-the-shelf 7-segment LED
readouts. (There was a *lot* of precision machining in that NLS readout
assembly. :-)


Which would be easy with a CNC machine. Can you imagine the problems
NCR had making their mechanical cash registers without CNC?

Indeed -- lots of custom fixturing. Actually, I think that the
frame for all the Plexiglas (or Lucite) panels was likely made with a
horizontal mill with a stack of cutters on it cutting all the guide
slots in the sides in a single pass, then assembled to make the overall
frame.


Their early models were brass & steel parts, wih a small glass window
over the mechanical displays.



LED replacements have been available for over 20 years, but they are
even more expensive than the lamps they replace.

Not when you count the cost of replacing them frequently, or
having a crucial indicator lamp burn out in the cockpit. (Of
course, they typically had two or three lamps per indicator, so you get
some warning when one lamp burns out.


They were $17 each, and the lamps were 85 cents. The problem is that
a lot of them were used on AC, and the early LED replacements not only
had to be DC, but the sockets had to be wired for the correct polarity.


--
You can't have a sense of humor, if you have no sense.

On 02/20/2012 05:52 PM, DoN. Nichols wrote:
On 2012-02-20, Gary A. wrote:
On 02/14/2012 10:14 PM, Michael A. Terrell wrote:

"DoN. Nichols" wrote:


I had a keyboard (originally from a Tektronix Silent-700 terminal


Texas Instruments made the Silent-700 line of terminals. I think I
still have one around here.


I have 2 rolls of paper for Silent-700, still in the black
plastic bags.

And what color is the paper by now? :-) Unless it was stored in
a cool environment the whole time, it is likely too dark to use. :-)
After all, the printing was done by flashing it with heat. That is what
made it "silent" compared to the mechanical marvel which was the ASR-33
Teletype. :-)

Enjoy,
DoN.

I'm sure they have deteriorated, by now. ( 40 yrs. )
I think the mechanical marvel is the model 35 Teletype.

One of the jobs I had at Tymshare, was evaluating terminals.
I had just about everything that could put characters on paper. :-)
Most were preproduction or prototypes.
There was a lot of strange terminals in the late 60's, early 70's.

--
Gary A. Gorgen | "From ideas to PRODUCTS"
| Tunxis Design Inc.
| Cupertino, Ca. 95014

On 2012-02-21, Michael A. Terrell wrote:

"DoN. Nichols" wrote:

On 2012-02-20, Michael A. Terrell wrote:

"DoN. Nichols" wrote:

On 2012-02-19, Michael A. Terrell wrote:

"DoN. Nichols" wrote:

[ ... ]

Non-Linear System's digital voltmeters used a series of stepper motors
to implement a Kelvi-Varley divider. Four digits, IIRC. Really noisy
with the sound-deadening cover off for test or repair. :-)

[ ... ]

Which would be easy with a CNC machine. Can you imagine the problems
NCR had making their mechanical cash registers without CNC?

Indeed -- lots of custom fixturing. Actually, I think that the
frame for all the Plexiglas (or Lucite) panels was likely made with a
horizontal mill with a stack of cutters on it cutting all the guide
slots in the sides in a single pass, then assembled to make the overall
frame.


Their early models were brass & steel parts, wih a small glass window
over the mechanical displays.

Hmm ... early being when? I first saw them back in 1960/1961
IIRC.

Speaking of "mechanical displays", we had one DVM at a later
date which was a servo driven Veeder-root counter which rotated the
digit drums do display the position of a 10-turn pot. I forget who made
those. Not very impressive, really. :-)



LED replacements have been available for over 20 years, but they are
even more expensive than the lamps they replace.

Not when you count the cost of replacing them frequently, or
having a crucial indicator lamp burn out in the cockpit. (Of
course, they typically had two or three lamps per indicator, so you get
some warning when one lamp burns out.


They were $17 each, and the lamps were 85 cents. The problem is that
a lot of them were used on AC, and the early LED replacements not only
had to be DC, but the sockets had to be wired for the correct polarity.

Yes -- a problem. That's why I wanted one with a built in
bridge rectifier. Are those made now?

O.K. A quick search finds this:

http://www.martekled.com/-strse-173/midget-flange-based-LED/Detail.bok

and they offer your choice of AC, positive center contact, and negative
center contact. (And, your choice of colors, too.) And the price is
down to $4.25 if you buy in sufficient quantities (1000). :-) Unit price
is $8.95 ea, which is better than it once was, at least.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"DoN. Nichols" wrote:

On 2012-02-21, Michael A. Terrell wrote:

Their early models were brass & steel parts, wih a small glass window
over the mechanical displays.

Hmm ... early being when? I first saw them back in 1960/1961
IIRC.


I'm talking about the all mechanical cash registers that were the
main products of NCR. The had several large buildings in the Dayton
area that were machine shops cranking out all the parts to feed their
assembly plants. They started building them over 100 years ago.


Speaking of "mechanical displays", we had one DVM at a later
date which was a servo driven Veeder-root counter which rotated the
digit drums do display the position of a 10-turn pot. I forget who made
those. Not very impressive, really. :-)


Sounds as bad as the old HP printer with a bunch of rubber wheels and
solenoids to rotate them to the proper number to log a frequency.



Yes -- a problem. That's why I wanted one with a built in
bridge rectifier. Are those made now?

O.K. A quick search finds this:

http://www.martekled.com/-strse-173/midget-flange-based-LED/Detail.bok

and they offer your choice of AC, positive center contact, and negative
center contact. (And, your choice of colors, too.) And the price is
down to $4.25 if you buy in sufficient quantities (1000). :-) Unit price
is $8.95 ea, which is better than it once was, at least.


That's a big improvement. The AC version in white would make a nice
universal replacement, but colored lamps would eliminate the need for
those tiny colored silicone rubber covers.

I first saw the 327/328 lamps on a tour of the VOA Bethany facility
while it was being upgraded from the original design. It was one tech's
job to wander around the facility to test & replace bad lamps. There
were over 3,000 in use, and they were still installing new equipment.

--
You can't have a sense of humor, if you have no sense.

On 2012-02-22, Michael A. Terrell wrote:

"DoN. Nichols" wrote:

On 2012-02-21, Michael A. Terrell wrote:

Their early models were brass & steel parts, wih a small glass window
over the mechanical displays.

Hmm ... early being when? I first saw them back in 1960/1961
IIRC.


I'm talking about the all mechanical cash registers that were the
main products of NCR. The had several large buildings in the Dayton
area that were machine shops cranking out all the parts to feed their
assembly plants. They started building them over 100 years ago.

O.K. I thought that we were still talking about the NLS digital
voltmeter readouts. :-)

Speaking of "mechanical displays", we had one DVM at a later
date which was a servo driven Veeder-root counter which rotated the
digit drums do display the position of a 10-turn pot. I forget who made
those. Not very impressive, really. :-)


Sounds as bad as the old HP printer with a bunch of rubber wheels and
solenoids to rotate them to the proper number to log a frequency.

How about the line printers (not HP) which had a drum of letter
forms rotating and a solenoid driving a hammer on the other side of the
paper to drive it into the ribbon. Early ones had all the letters lined
up, but tended to fail with the massive current surge when you printed a
line of all '*' or all '_'. The latter, btw, made a nice "tear here"
weakened point. :-)



Yes -- a problem. That's why I wanted one with a built in
bridge rectifier. Are those made now?

O.K. A quick search finds this:

http://www.martekled.com/-strse-173/midget-flange-based-LED/Detail.bok

and they offer your choice of AC, positive center contact, and negative
center contact. (And, your choice of colors, too.) And the price is
down to $4.25 if you buy in sufficient quantities (1000). :-) Unit price
is $8.95 ea, which is better than it once was, at least.


That's a big improvement. The AC version in white would make a nice
universal replacement,

I wonder why they make the polarized DC versions? Perhaps
brighter? I didn't see a clue that the AC ones cost any more -- though
they *should*. :-)

but colored lamps would eliminate the need for
those tiny colored silicone rubber covers.

The ones which tended to tear when you tried to pull them over
the rim of the bulb sleeve, or when you pressed on them to eject a bad
bulb. :-) Who was it -- Honeywell -- who made those switch assemblies.
I know that MicroSwitch made the snap-on switch elements.

I first saw the 327/328 lamps on a tour of the VOA Bethany facility
while it was being upgraded from the original design. It was one tech's
job to wander around the facility to test & replace bad lamps. There
were over 3,000 in use, and they were still installing new equipment.

With a pushbutton on each panel to light all bulbs on that
panel? There were such on the flight simulator instructor's control
panel which a company I worked for for a while made.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"DoN. Nichols" wrote:

On 2012-02-22, Michael A. Terrell wrote:

I'm talking about the all mechanical cash registers that were the
main products of NCR. The had several large buildings in the Dayton
area that were machine shops cranking out all the parts to feed their
assembly plants. They started building them over 100 years ago.

O.K. I thought that we were still talking about the NLS digital
voltmeter readouts. :-)


Sorry, I thought 'NCR' was enough information. Of course I grew up
near there and knew some employees.


How about the line printers (not HP) which had a drum of letter
forms rotating and a solenoid driving a hammer on the other side of the
paper to drive it into the ribbon. Early ones had all the letters lined
up, but tended to fail with the massive current surge when you printed a
line of all '*' or all '_'. The latter, btw, made a nice "tear here"
weakened point. :-)


We had a large DataProducts drum printer on the SATE for the PRC-77.
It would shake the entire computer booth when it printed a line of
asteriks to signal a failure. I was there one day when the engineer
from Data general was doing a core dump to the printer. it didn't have
a refolder, so the paper was sraying off the ceiling. ;-)


Years later, I had to scrap a tractor trailer load of those printers,
along with a trailer full of VAX based CAD systems that had come off
lease. The owner wanted cerified destruction to keep them off the
market. It made me sick to trash the uncased NTSC studio grade
monitors. but the contrast said they could not be resold. A lot of small
TV stations would have paid $1000 each for them, for spares.


I wonder why they make the polarized DC versions? Perhaps
brighter? I didn't see a clue that the AC ones cost any more -- though
they *should*. :-)


Probably for the anal retentive types? Also, it would allow for
simple bicolor indicators, by simply inverting the polarity if two are
wired in parallel.


but colored lamps would eliminate the need for
those tiny colored silicone rubber covers.

The ones which tended to tear when you tried to pull them over
the rim of the bulb sleeve, or when you pressed on them to eject a bad
bulb. :-) Who was it -- Honeywell -- who made those switch assemblies.
I know that MicroSwitch made the snap-on switch elements.


Master Specialties. I may still have a new switch or two left.

http://www.marineairsupply.com/catalogs/10_Series.pdf


I first saw the 327/328 lamps on a tour of the VOA Bethany facility
while it was being upgraded from the original design. It was one tech's
job to wander around the facility to test & replace bad lamps. There
were over 3,000 in use, and they were still installing new equipment.

With a pushbutton on each panel to light all bulbs on that
panel? There were such on the flight simulator instructor's control
panel which a company I worked for for a while made.


They used the switch itself, with the console in diagnostics mode.
He would just push a switch, then pull it out with what looked like an
IC extractor and replace a bad lamp, and test again.


--
You can't have a sense of humor, if you have no sense.

On Feb 18, 10:39*pm, rangerssuck wrote:
On Feb 16, 11:13*pm, "DoN. Nichols" wrote:

* * * * Come to think if it -- with the proliferation of LEDs, does
anyone still make and sell NE2s? *Last I've seen them has been in AC
power switches in power fanout boxes for home computers, in generally
blinking or not even that as the lamps age. :-)

* * * * Enjoy,
* * * * * * * * DoN.

Chicago Miniaturehttp://www.chml.com/products/pdf/5-4.pdf

Several flavors in stock at Mouser.

Now I have to wonder why it is that whenever I do a new design, at
least one part goes obsolete before the design is finished. But I can
still buy NE2s by the thousands?

Millions of power bars sold every year still have a neon indicator in
them. They're cheap and they're "green", neon being basically a by-
product of air liquification and fractionation. Think of how much
toxic waste an LED needs to get manufactured.

Stan