AT&T 305B Buckling Spring Keyboard

[MissileMike]

Here's one from NCBound that you don't see to often, an AT&T buckling spring board.  They're a little quieter than the IBM keyboards, from my experience...  They're definitely not rebadged IBMs as the case is completely different.

link

[MissileMike]

And here is another 45$ BIN and it looks in very good condition.

[Sam]

Do you know any details about the buckling springs in these?  Similar to a Model M, with a membrane, or do they use Model F style capacitance switches, or something different?

[MissileMike]

Do you know any details about the buckling springs in these?  Similar to a Model M, with a membrane, or do they use Model F style capacitance switches, or something different?

The springs themselves seem identical to the model M.  I am not sure why they seem quieter.  It could be because I have only seen 1 AT&T board and it was a fluke, or the maybe the barrel is different.

[msiegel]

wow!

key construction is different. see photo 6

[MissileMike]

The second one I posted sold.  Did someone here snag it?

Model M keycaps do work with these boards, but the colors do not match.  These are pretty much white, instead of the M beige.  They also do italics on the letters.  But, unlike the Dell Model Ms, these are significantly different than their IBM brothers.

[MissileMike]

One of these days, I am going to take mine apart and do a side by side with a 1391401....

[itlnstln]

I still would like to know the story behind these.  I wonder if AT&T manufactured these themselves, was there any licensing involved, etc.

[Sam]

The BIN must have sold soon after the OP was posted.  By the time I saw the post a couple hours later it was already gone.

[keyb_gr]

I could swear we had a discussion of these at some point... Ah, there it is. Maybe it's in the wiki, too.

[ch_123]

wow!

key construction is different. see photo 6

I've seen Model M keystems where parts were not hollow. Two holes is interesting, but it's perfectly conceivable that there are IBM keyboards out there with such key stems.

I still would like to know the story behind these.  I wonder if AT&T manufactured these themselves, was there any licensing involved, etc.

FCC ID says it was made by Lucent. The insides look nothing like anything IBM or Lexmark made. Why they bothered making their own is a complete mystery though.

[keyb_gr]

FCC ID says it was made by Lucent.

... which emerged out of AT&T in the '90s.

The insides look nothing like anything IBM or Lexmark made. Why they bothered making their own is a complete mystery though.

They had a patent for a quietened BS mechanism.

[Sam]

... which emerged out of AT&T in the '90s.

They had a patent for a quietened BS mechanism.

Interesting.

In accordance with the present invention, acoustical noise generated by the buckling coil spring in a key switch mechanism is minimized by insertion into an opening formed by the coils of the spring, a cylindrical core formed from a foam type material and positioning it in a predetermined location within the opening in the spring.

Great, another keyboard with foam in it to deteriorate.  With the beam springs, you have to worry about that piece of rubber deteriorating.  With Model F's, it's the foam.  With Model M's, it's the plastic rivets.  With these, maybe it'll be the sound absorbing foam.  Somebody please design a good keyboard without any components that can deteriorate in my lifetime.

[MissileMike]

I don't think they ever put this patent to use.  There is no foam in my AT&T....

[MissileMike]

Another oddity about these AT&T boards...  Almost all of them seem to have a yellow space bar.

[Sam]

There is no foam in my AT&T....

Hey, see, it already deteriorated into nothing!  At least it's environmentally friendly foam.

[ch_123]

Some of the Greenock Model Ms have yellowish spacebars too, for some reason.

Maybe they were stealing samples from the Alps factory on the sly.

[ch_123]

Great, another keyboard with foam in it to deteriorate.  With the beam springs, you have to worry about that piece of rubber deteriorating.  With Model F's, it's the foam.  With Model M's, it's the plastic rivets.  With these, maybe it'll be the sound absorbing foam.  Somebody please design a good keyboard without any components that can deteriorate in my lifetime.

With the Model F, it's only the stuff around the edges that really disintegrates. I think this was one of Ripster's trolls a few centuries ago.

[JBert]

What's the problem? It doesn't cause any trouble if you leave it undisturbed, and even if it deteriorates, it won't jam the keys.

With the beam springs, you could have the rubber falling from between the keys if you turned the keyboard upside down, and even then that seems unlikely.

[keyb_gr]

I don't think they ever put this patent to use.  There is no foam in my AT&T....

So they made (essentially) bog standard BS boards instead? Wacky. Well, at least there's no foam to go bad there...

Some of the Greenock Model Ms have yellowish spacebars too, for some reason.

That seems quite normal. With a board that had considerable sun exposure, you'd typically see a yellowed spacebar (it's ABS) and fading on the non-black legends, like the brown ones on the numpad keys.

[msiegel]

the photo i took looks awful; there *was* deterioration throughout the sheet.

i'm with sam, we should figure out a replacement for foam. felt or something fibrous? i wish i knew...

[JBert]

Guess what Stage Two of foam decomposition is?

From my Selectric Cleaning Mod.
[ Disintegrated foam dust bunnies ]

Still not a problem for a model F keyboard. Those few moving parts (the springs and hammers) are actually sealed off from the foam by the barrel assemblies being pressed hard onto the PCB.