[Build log] IBM Model M 122-key ANSI Conversion

[akoimeexx]

So a friend was cleaning out the basement of his house, and ran across what we thought were two IBM Model F Terminal keyboards. Since he wasn't tech-inclined, he kept the better of the two and sold it off, giving me the other one that someone had previously mangled in an unfinished conversion project. I hopped on the IRC channel to talk with people who know a good deal more about identifying the keyboards than myself (Thanks again Compgeke!), and found out what I had was actually a Model M.

IBM Model M 122-key, closed

keyboard-1.png (743.42 KiB) Viewed 2699 times

I love the heft and weight of the keyboard, and since it's already been partially modified (the underlying key plane has been hacked up and melted together to change the 'plus' arrow key placement to 'inverse t', and tabs were cut on the top cover to presumably add Context/OS keys) I'd like to refurbish it with a new keyswitch setup (the electronics inside were -gone-). Here's what I have to work with from the original board:

IBM Model M 122-key, open

keyboard-2.png (730.59 KiB) Viewed 2699 times

I'm currently debating using Cherry MX Blue switches for most of the keys, as I want the audible and tactile feedback they provide; but I don't know how well they would fit and have been trying fruitlessly to get a hold of someone at Cherry corp for a single sample request each of Blue and Green MX's (green for the spacebar, I feel would work well). I will be writing my own firmware to an Atmel chip as opposed to a Teensy (I don't like to waste a development board on something that will be basically permanent).

I'll keep this thread updated as a build log for the project and will post any new developments as they happen. When the source for the keyboard firmware and driver is finished I will post that as well.
In the meanwhile, anyone know of a company or individual that I can request a couple sample switches from? Any suggestions or critiques on this conversion would be most appreciated as well.

[Halvar]

Oh dear, that thing is destroyed. The broken plate, missing controller, missing parts and full keys, keycaps written on with a marker... this looks sad.

I would start by reading about bolt mods and how a Model M exactly works and to make a plan of all that would be needed to make this work again. If you're asking for "a couple of sample switches" that suggests that you don't seem to know how a Model M works yet.

Replacement parts for Model Ms are not really cheap, I'm afraid it might turn out that the most economic way to turn this into a working an usable keyboard would be to start with this replacement part, and combine parts. Good luck!

[akoimeexx]

Yeah; basically have a case and keyplane, plus most of the key caps and key slides. This is why I'm looking to replace the internals with mechanical keyswitches and a custom uC; I'll wiring it for bluetooth connectivity and USB charging for a LiPoly battery.

Edit: That link looks like a Model F?

[kint]

Halvar, as far as I understood theres nothing more left than keycaps barrel plate and case and akoimeexx wants to mod that. True, this is pretty much as worse as it will get. I'm not really into Model Ms but maybe this offer gives a hint about the worth of your beaten unit: http://deskthority.net/marketplace-f11/ ... ilit=model
So akoimeexx I'm with you there, modding the fu... ..n out of it is probably the best idea. You won't get sample switches from Cherry - they are not that kind of business. I don't know which shop sells individual switches in the USA, but there are some afair. cheapest option is maybe 7bits thread: http://deskthority.net/marketplace-f11/ ... t2760.html although I'm not sure on the current status, what's available and such. So to get some MX just for testing maybe it's best to do an ad in the marketplace.
Just as a reminder - the casing for all MX switches regardless of blue, black, red, etc is identical, so if you just want to see if they fit into the project get the cheapest MX you can find out there.

[Kurk]

If you love to tinker and make the nearly impossible possible then this is a nice project. If not, you're better off getting a working IBM M 122.
Have you thought about this?
*IBM M keycaps do not fit on Cherry MX switches (and vice versa).
*You would need to create a bent mounting plate if you go for Cherry MX switches; that alone is a lot of work or very expensive.
*Economy: 122 Cherry MX switches will cost you approx. 80 USD. A set of MX keycaps at least another 50 USD.

I don't want to talk you out of this, just warning of the rocky road ahead. It would be great if you manage to pull it off.

O yeah, 7bit will soon tune in and show you the way to his Cherry MX group buy: http://deskthority.net/marketplace-f11/ ... t2760.html

[kint]

...O yeah, 7bit will soon tune in and show you the way to his Cherry MX group buy: http://deskthority.net/marketplace-f11/ ... t2760.html

To be precise: He will also show the way to his MX keycaps groub buy...

[Halvar]

He might also mention his Matias GB (cheaper switches), although it will be hard to find keycaps for a Terminal keyboard.

Sorry, it must have totally overlooked the next-to-last paragraph in the OP. I'm either getting old or it wasn't there yet when I started writing...

It's in fact a great project to make your own bluetooth controller, and I think there will be much interest for that here. I'm not sure if I would use this huge wreck as a base. Kurk's points are valid, and additionally, MX blue switches are not comparable in feel to a real buckling spring keyboard.