BTC 5151 - Foam and Foil w/Key Tronic style caps

[snuci]

I wasn't going to post this but I was shocked at how good the foam and foil is holding up on these switches! Since I took the pics anyway, I figured, why not? The foam is nothing like the Key Tronic foam and foil that I've replaced on many keyboards. This keyboard is unmarked on the outside and speculation was that it was a PC based Key Tronic keyboard. The sticker indicates that this came from a Research facility that had published some keyboard research. If it was Key Tronic, some searching around determined that there were some interesting keyboards that Key Tronic had made; including one with a microphone that you could dictate to (back in the old days). But alas, it is not a special keyboard.

This keyboard is unmarked, other than the asset sticker, so the BTC 5151 identification is coming from the PCB board markings. This one is from the 50th week of 1984.

Anyway, here are some pics:

BTC 5151 - keyboard profile

BTC 5151 - keyboard profile.JPG (242.51 KiB) Viewed 2606 times

BTC 5151 - keyboard front

BTC 5151 - keyboard front.JPG (260.47 KiB) Viewed 2606 times

BTC 5151 - keyboard back

BTC 5151 - keyboard back.JPG (188.79 KiB) Viewed 2606 times

BTC 5151 - top of switch plate

BTC 5151 - top of switch plate.JPG (264.08 KiB) Viewed 2606 times

BTC 5151 - bottom of foam and foil switch plate

BTC 5151 - bottom of foam and foil switch plate.JPG (301.92 KiB) Viewed 2606 times

BTC 5151 - PCB top

BTC 5151 - PCB top.JPG (353.52 KiB) Viewed 2606 times

BTC 5151 - PCB back

BTC 5151 - PCB back.JPG (281.22 KiB) Viewed 2606 times

BTC 5151 - PCB identification

BTC 5151 - PCB identification.JPG (313.7 KiB) Viewed 2606 times

BTC 5151 - top of key switch with spring

BTC 5151 - top of key switch with spring.JPG (210.16 KiB) Viewed 2606 times

BTC 5151 - top of key switch overhead

BTC 5151 - top of key switch overhead.JPG (202.22 KiB) Viewed 2606 times

BTC 5151 - foam and foil is still pristine!

BTC 5151 - foam and foil is still pristine!.JPG (219.07 KiB) Viewed 2606 times

BTC 5151 - bottom of key switches

BTC 5151 - bottom of key switches.JPG (283.29 KiB) Viewed 2606 times

BTC 5151 - key switch with spring removed

BTC 5151 - key switch with spring removed.JPG (248.64 KiB) Viewed 2606 times

BTC 5151 - Keytronic style key caps

BTC 5151 - Keytronic style key caps.JPG (207.89 KiB) Viewed 2606 times

[terrycherry]

Rare to see the very early 1984 BTC keyboard!
The foam and foil weren't damage in this age. Great made indeed.
My 1983 made KeyTronic butterfly's foam and foil were damage and bad shape.

[snuci]

I know what you mean. Two weeks ago, I was putting new foam and foil in two Victor 9000 Key Tronics made keyboards. The foam was toast. You can see what those look like in this previous post here: photos-f62/sirius-s1-victor-9000-1982-t6068.html Nice keyboards (I have two Victor 9000 computers to go with them) but bad foam like all Key Tronic keyboards I've come across.

[terrycherry]

Still cleaning some parts.
I'm considering to put the new variant foam and foil to the butterfly.

[Chyros]

My three Wang 725s with KT foam and foil also all have their foam intact and pristine, they haven't crumbled.

Frankly I haven't had a single F&F board with crumbled Oo . I wonder if there was a difference in the foam they used over time.

[seebart]

My three Wang 725s with KT foam and foil also all have their foam intact and pristine, they haven't crumbled.

Frankly I haven't had a single F&F board with crumbled Oo . I wonder if there was a difference in the foam they used over time.

I have...but some were intact:

keyboards-f2/key-tronic-corp-serial-no- ... y%20tronic

[Chyros]

My three Wang 725s with KT foam and foil also all have their foam intact and pristine, they haven't crumbled.

Frankly I haven't had a single F&F board with crumbled Oo . I wonder if there was a difference in the foam they used over time.

I have...but some were intact:

keyboards-f2/key-tronic-corp-serial-no- ... y%20tronic

Interesting, the foam in yours is green! The ones in all my boards is brown for Key Tronic, and yellow in my BTC.

[Daniel Beardsmore]

Hm ... there are broadly two different manufacturing approaches here. This one has exposed pads on the PCB. If this is capacitive, then presumably the foil discs are plastic-coated.

Other examples have the pads covered in solder mask, so the foil discs could be bare metal:

[wiki]BTC 5100[/wiki]
[wiki]BTC 5060[/wiki]

I don't have any foam and foil keyboards, but I do have some loose Alphameric resistive modules, and the matt finish foil discs on those are …

Well, here's the strange thing. Next to me was a small Stanley Philips screwdriver, which I tested (not sure why) and the shaft is not conductive. It looks like metal, but no current passes through it. The tip is, however, conductive!

I seem to have fallen through a crack in the laws of physics. The foil discs on my Alphameric resistive modules don't register any current, but in this altered state of reality I can't draw any conclusions.