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geekhack Community => Keyboards => Topic started by: blakespot on Tue, 23 August 2011, 08:42:10

Title: Switches in Acorn A5000 keyboard?
Post by: blakespot on Tue, 23 August 2011, 08:42:10

I have an Acorn Archimedes A5000 and am wondering what type of switches are used in its keyboard. They feel very, very smooth, with completely linear resistance. It feels like I imagine Cherry Reds or Blacks feel, based on what I've read.

The keyboard says 25-ALB55-1010554 on a sticker underneath.

Thanks.



bp

Title: Switches in Acorn A5000 keyboard?
Post by: blakespot on Tue, 23 August 2011, 20:38:44

I just took this pic of the switch on the Acorn keyboard in question. What sort of switch is this? Seems super basic / simplistic.

(http://farm7.static.flickr.com/6066/6075240284_4f0e7bdc4c.jpg) (http://www.flickr.com/photos/blakespot/6075240284/)
Acorn A5000 key switch (http://www.flickr.com/photos/blakespot/6075240284/) by blakespot (http://www.flickr.com/people/blakespot/), on Flickr


bp

Title: Switches in Acorn A5000 keyboard?
Post by: SmallFry on Tue, 23 August 2011, 20:45:57

What the heck? It almost seems like it is a dome underneath there, but that doesn't make sense. Do you have a picture of the internals?

Title: Switches in Acorn A5000 keyboard?
Post by: SmallFry on Tue, 23 August 2011, 20:56:24

According to this article, A4000 though. (http://"http://www.classicacorn.freeuk.com/32bit_hardware/a4000kboard/a4000_keyboard.html) The board is a rubber dome as I predicted. What a shame for such a pretty board.

Title: Switches in Acorn A5000 keyboard?
Post by: blakespot on Tue, 23 August 2011, 20:59:41

There is no dome under there. There is just a little switch arm sitting above the metal baseplate. The only resistance is coming from that spring.


bp

Title: Switches in Acorn A5000 keyboard?
Post by: blakespot on Tue, 23 August 2011, 21:06:53

(http://farm7.static.flickr.com/6074/6074782067_a8f38a2bcb.jpg) (http://www.flickr.com/photos/blakespot/6074782067/)
Acorn A5000 key switch (http://www.flickr.com/photos/blakespot/6074782067/) by blakespot (http://www.flickr.com/people/blakespot/), on Flickr

Title: Switches in Acorn A5000 keyboard?
Post by: SmallFry on Tue, 23 August 2011, 21:19:24

Then my best guess would be to disassemble the board via the instructions of the article I posted. It may be a buckling spring.(NEVERMIND BS ARE TACTILE AND CLICKY) WHOOPS! I haven't any idea as I've never encountered such a board. The only surefire way would be to disassemble.

Title: Switches in Acorn A5000 keyboard?
Post by: Arcanius on Tue, 23 August 2011, 22:07:34

Very interesting switch. Probably propritary? Is looks like a simple spring over membrane! RipOmeter it!

Title: Switches in Acorn A5000 keyboard?
Post by: blakespot on Tue, 23 August 2011, 22:34:17

Inside the cylinder on the keycap is a rod that ultimately pressed down on the little lever switch at the base of the mechanism. It seems crazy basic.

There is linear resistance all the way down, with no variation -- super smooth. Too smooth for my tastes, really.

So this is not a commonly used approach?



bp

Title: Switches in Acorn A5000 keyboard?
Post by: SmallFry on Tue, 23 August 2011, 22:42:23

Nope. It looks like a very pretty board though, what a shame that they are not compatible keycaps.

Title: Switches in Acorn A5000 keyboard?
Post by: The Solutor on Wed, 24 August 2011, 02:26:46

Ah the archimedes, my forbidden dream at the time

Title: Re: Switches in Acorn A5000 keyboard?
Post by: blakespot on Sun, 18 November 2012, 17:15:22

bump

Title: Re: Switches in Acorn A5000 keyboard?
Post by: rowdy on Sun, 18 November 2012, 18:12:37

I used to have an Archimedes.  Very fast computer, for the time.

Given the lack of response, you might have to disassemble it yourself, and then post a picture here for future reference :)

Title: Re: Switches in Acorn A5000 keyboard?
Post by: IvanIvanovich on Sun, 18 November 2012, 18:22:36

Appears to be the same thing used by Amstrad and some others. I guess it's something that primarily stayed in Britain and died.

Title: Re: Switches in Acorn A5000 keyboard?
Post by: TotalChaos on Sun, 18 November 2012, 20:40:48

It looks and sounds awesome!

Please please please place nickels on a key until it registers a keypress.  This tells us its activation force!  Do it for keyboard science!  We need to know!