Recovered a mystery keyboard from the jobsite... Help!

[Mzen]

To keep the long story short, I've managed to spot one of the sweet-looking keyboards from the place I work at in a bucket full of random broken stuff. I asked what was supposed to happen there and the technician simply said "it's scrap metal". Hmm... "Any chance I might get a hold of it for myself?"

After a short talk with the master technician, he decided that I could have it. Success!

It was looking miserable when I got it home, but after a full evening cleaning up everything and plugging it into a PS/2 to USB converter... It was in absolutely perfect working order. The only weird thing at first was that something seemed to be broken underneath the space bar, but it turned out that the stabilizer was just placed the wrong way.

Here's the exemplar in question, after cleanup:


And the back label:


There is absolutely no information online that I can find about this keyboard, except for this PDF on the GMK website:
https://www.gmk-electronic-design.de/fileadmin/user_upload/Datenbl%C3%A4tter/Datenblatt_Multifunktionskeyboard.pdf

Now for my question... I'm particularly interested in the possibility of being able to use the top rows to create some custom macros, I assume that's the main purpose of that bit:


I've tried multiple key combinations and lengths of time, but I didn't get any results. I also assume that little LED number can go up to nine for different layers... but I can't change it no matter what. By the way, all the buttons on the top layer currently correspond to "F1+Alt", "F2+Alt", etc. While the second row corresponds to "F1+Shift", "F2+Shift" and so on. The "Prog" and "Layer" buttons don't have any functions associated with them.

Any ideas on how to get that working? Or maybe some third-party software that could allow me to change what they currently do?

[Nuum]

Looks like a Cherry G81-8308, maybe that helps you find more information?

[Findecanor]

I think I saw this in a thread last year or so, but I don't remember which message board.
Most keys are Cherry MY, and only the two top rows of keys are Cherry MX, right?

[Mzen]

Yeah, definitely MX Clears, lovely PTB keycaps as well. Unfortunately, I forgot to take some pictures when I had the whole thing pulled apart, except this random one to show to a buddy of mine:


As seen here, this one seems to have been manufactured around October of 2016.


I will look into that Cherry G81-8308, much appreciated!

[Findecanor]

Oh, full MX Clears. Nice!

[tp4tissue]

As with all industrial looking boards,  Go over it with a geiger counter to be safe.

[Tactile]

It's pretty common for special purpose keyboards to send key combinations. I have such a keyboard and here's how I solved the problem.

[Mzen]

It's pretty common for special purpose keyboards to send key combinations. I have such a keyboard and here's how I solved the problem.

I'm handy when it comes to computers in general, but that is QUITE the solution
Unfortunately, my programming skills are horribly rusted. I might be able to study that and figure out how it works, but I would also appreciate it if there was an easier solution haha

It is unfortunate that the Prog and Layer keys don't seem to do anything compared to the video I've seen on the Cherry G81-8308 from Chyrosran22, and as expected the official Cherry software doesn't work on this. Either way, thank you for your solution! I would require a specific converter for that, wouldn't I? Haven't heard about the Soarer stuff before this post.

[Tactile]

It's pretty common for special purpose keyboards to send key combinations. I have such a keyboard and here's how I solved the problem.

I'm handy when it comes to computers in general, but that is QUITE the solution
Unfortunately, my programming skills are horribly rusted. I might be able to study that and figure out how it works, but I would also appreciate it if there was an easier solution haha

It is unfortunate that the Prog and Layer keys don't seem to do anything compared to the video I've seen on the Cherry G81-8308 from Chyrosran22, and as expected the official Cherry software doesn't work on this. Either way, thank you for your solution! I would require a specific converter for that, wouldn't I? Haven't heard about the Soarer stuff before this post.

My keyboard was PS/2. Soarer's converter is a very commonly used gadget to convert a PS/2 keyboard to USB. In addition to making this conversion it can also be used to add programming (to re-map keys, for example) and layers to the converted keyboard. If you search for "soarer's converter", both here and on the web, you'll find lots of info. The instructions & firmware required to make it work are right here on Geekhack.

[Rob27shred]

Wow, what an awesome find OP! It wouldn't be a G81 model as G81 denoted MY switches & your has MX switches with product no. should start with G80. If it is a Cherry made board though, I see it is labeled GMK & does not have any product or serial numbers I have ever seen with any Cherry board. Which leads me to believe this is a strictly a GMK product not an OEM Cherry board just marked GMK. Maybe send GMK CS or Livingspeedbump a message about it. I'm sure they could give you more info on it. Anyways GL getting it working with a modern PC & if not you still have one hell of a board to add to your collection!

Edit: Also those whiteish keycaps are most likely lasered POM as that is what Cherry has been using ever since selling their keycap making equipment to GMK. The colored ones may be dye subbed PBT though.