deskthority

This is from the dome and foil keyboard I'm trying to identify atm. The board is a semi-integrated printer keyboard that's not salvageable anymore so I opened it up to examine a bit and apart from the strange dome and foil switch (it's not very good) I also found it uses thick tripleshot keycaps, some even with windows! So I thought I'd share this rather interesting find .

The caps:


Reverse side:


Obverse side:


The windowed tripleshots are my favourite.


Switch parts:

Very cool! They look a bit like Topre keycaps.

Next thing to find: quadrupleshots.

HaaTa found a very similar one a while ago: photos-f62/burroughs-b25-k2-3675-6104-t12617.html
Looks like the caps could fit on Topre mount. I think I've seen some alike keycaps from Brother typewriters that loosely fit on Topre mount.

Yes, you're right! I knew I'd seen them somewhere recently . So I guess it's Brother Prototopre (or Brototopre ) dome and foil then?

If these fit Topre that'd be kickass .

The keys caps look similar to keys from a Brother typewriter.


I will check tomorrow with my CE-650 ...

ohaimark wrote: Next thing to find: quadrupleshots.

Yamaha made some

Good god... The tooling costs on those must have been half the price of the product line.

quadrupleshots... oh great, yet another thing to covet :'(

Fuck me Yamaha really spared no expense Oo .

Thanks to share this unknown switch! I had seem this switch but didn't know what it inside.
Is it the Brother KB-50 keyboard(1983.11made for brother printer)

I generally call this switch "Prototopre". I've seen it as early as 1982 in some Epson/Seikosha keyboards.

Topre, didn't even start looking into office/business equipment until 1983, but the designs are very similar. My theory is that either some engineers that did the original design or used it as a base for their own (more reliable) switch.

My current theory is that it was created by Brother as some keyboards have "Brother-like" model numbers on the PCB. But not all of them. It may even have been some independent design firm for all we know. Also, the only patent reference I've seen to this switch is also in a Brother patent: http://www.google.com.gh/patents/US3900712 (1975).

Some later IBM RT keyboards used a membrane variant of this switch that was very clearly. These are more clearly shown in patents.

This list even includes a few keyboards I haven't posted yet

Prototopre
DSC03481 Q603A

DSC02895 Burroughs B25 K2

Untitled Seikosha 8620

Untitled IBM RT E57888 6298389

Brother "Topre-like" Domes
DSC_1382 Unisys T27-K5
Note, the graphite pads. Also, Burroughs became Unisys when it merged with Sperry-Rand (Univac). Also note that the mylar membrane supports "both" contact and capacitive switches!

IBM RT E57888 6247440
Uses a mylar membrane closer to what the Model M uses.

Oh, and I have at least one more different Epson keyboard that has this switch (but it's somewhere in my "take photos of" pile )

terrycherry wrote: Thanks to share this unknown switch! I had seem this switch but didn't know what it inside.
Is it the Brother KB-50 keyboard(1983.11made for brother printer)

I can't find pictures of the exact model, but some Brother models did look vaguely like it, so it's probably something made by Brother, yes.

Thanks to HaaTa answer.
Here's the [JP][1983.11]Brother KB-50(for Brother HR-15 & HR-15XL Printer)
[US Magazine advert][1984.11.27]PC Mag(page402)

[US Magazine advert][1984.12.11]PC Mag(page274)
Compare to Chyros and HaaTa disassemble picture of it, the slider looks very similar to Monterey dome with slider and BTC dome with slider. Another wild guess the BTC and Monterey were copied something from Brother.
Here's my [AT][TW][1994.07]Super Gate keyboard(FCCID KU6-SG-1000)[(Tactile)Monterey dome with slider(Yellow)]

I wonder how you repair this kind of switch. I have a IBM RT board (the early square silver label variety) and many of the keys don't register easily. I'm not sure if it's soarer's converter or the electrical contacts.

The contact plates don't have any soldermask on them so I imagine they'd rust easily. The foam holding the disc to the done is also rubbish and can easily fall off.