Anyone ever used an ASR-43 Teletype?

[ch_123]

There was one lying around in my college which I had a look at. It white sliders that looked something like this. The underside of the keycaps looked similar to the ones in those pictures.

The feel off them was what really interested me - they somewhat reminded me of Beam Springs - there was a short linear travel followed by an impressive collapse. Nonetheless, they were nowhere near as good as the real deal, they felt stiffer, and there was a lot of friction in the action (however, the friction seemed to vary from key to key, so it could be an issue of wear)

Underneath the cover of the keyboard, there was an unused switch with a black slider that was of a different shape to the others. This was much softer, so it felt much more Beam Spring like than the others.

The switches were definitely electro-mechanical - there was two contacts coming out of the bottom that were soldered to a PCB. I didn't have any screwdrivers with me at the time, but the next time around it, I might try and dismantle one of the switches to see what's inside.

I have some pictures of the switches which I will post later.

[microsoft windows]

They're old ALPS key switches.

[ch_123]

I was aware of that. Either way, I'm not entirely convinced that they were exactly the same, they just looked similar. I'll have to upload my pics later.

[ricercar]

nice. I'm too much a noob. Never used one of those. And free. You're 1337

Last year I missed my chance to get my long-coveted new-school Texas Instruments Silent 700; $10 was too far over budget the day after i was laid off. We used to do all our h4xx0ring with these, two decades before the word was invented.

[ricercar]

Analog communications device for crossbar switching matrix. Effective in its time, but the frequency response was dismal, 300-3000Hz +/- 12dB. It does have mechanical switches. You pretty much had to bottom out each in daily use. Oh, it was quite noisy, especially at the start of a session.

[ricercar]

6-20V nominal, 100V ring @ 50Hz. We used to hook up regular light bulbs for silent ringers. They'd flicker in the wee hours when Ma Bell tested the lines for unauthorised phones.

[Specter_57]

...

I see a rotary telephone in one of those pics.

I still have several of the old 500 series types...and one is here on my computer desk...and it gets everyday use...along with an only slightly more modern push button DTMF type.

Friends think I'm a bit odd for still using it...but then  I still use fountain pens too....

...those coiled telephone cords could be pressed into service if necessary on your keyboards....I've actually seen it done....

...and...telephones sit at -48v on-hook and about 6-7v off-hook for the older mechanical phones....ring voltage about as stated, ring frequency 17-25Hz...and that 300-3000 Hz bandwidth was actually deliberate...phones were designed for intelligibility rather than fidelity.


...and a page about telephone stuff....  http://www.telephonecollectors.org/library/weco/weco.htm

...and for something completely different...http://www.i-hacked.com/content/view/205/47/

...and ...sorry for taking the post sort-of off-topic.

.........
Spec57

[JBert]

[IMG of article]

I love how they promoted the "CAPS LOCK" key as a "clever keyboard feature". x years later we're still trying to get rid of it.

Also, in the last one pictured a lot of keys are covered up by a plexi-glass plate. Why they'd do that for?

[ch_123]

I think that pic was from a computer museum.