Cherry G81-3000 broken? :( (Update: Adapt Liberty to USB/PS2

[Masterchief79]

Hey guys,
a friend of mine bought a Razer Black Widow and told me about the differences between normal and mechanical keyboards. I looked around in my room (let's say you can't set a foot without stepping on 3 or 4 CPUs, Mainboards or GFX cards) and I really found an old Cherry G81-3000 (LGNDE /00) with MX Clear switches.
So, I cleaned it carefully wih spiritus and now it's as good as new. Then I plugged it on my Asus Rampage Extreme mainboard and powered it up.
The strange thing is, the keyboard is mostly working, just a few keys are causing problems. These are "3-E-D-C" which are working sometimes, but regularly not - there seems to be a connection with the Num-Lock-Key ("E" for example is seldomly working after releasing Num-Lock). Further, "Q-A-Y"(or QAZ for your English layout), "Tab", "Escape", "Tilde" and "1" don't work at all. I marked it on the pics below.

Note that it originally has the "big" PS2 out for the old Pentium MMX mainboards, and that I'm using an adapter.

Any suggestions to maybe get it working again? Torx screws ain't a problem, neither is soldering, just tell me what to do

[mbodrov]

I'm sorry to say that your keyboard does not have MX Clear, but instead MY switches, which are semi-mechanical (plunger over membrane). MY switches are often cited among the worst-feeling of them all, described as "typing on wet newspapers." This keyboard won't give you a good idea of what mechanical keyboard are about, so it probably isn't worth repairing.

Keyboards whose model number starts with G81 use MY switches. Those starting with G80 have MX, which is what you need to look for.

[Masterchief79]

Oh, okay, pity but good to know. As I said, till yesterday I didn't even know mechanical keyboards existed.^^ I looked around and found a pic titled "MX Clear" and the switches looked exactly like mine. This is a pic of my keyboard's switches:

// Yep you're right MY... Well, next question, what keyboard am I supposed to buy? I'm more or less through with my G15, using it for four years now every day... Doesn't feel nice any more, trust me. I look around if I find another 15 year old mechanical keyboard laying around..^^ but in case not, prepare your purchase advising skills >:D

[mbodrov]

Those are MY switches all right. The "+" shape and the color match, but the body of the switch looks very different from MX. This is MX:



Not to worry though, if you want to learn about mechanical keyboards you've come to the right place.

[Masterchief79]

Sounds good. I really found a keyboard with MX black switches in our house, but when i had a closer look.. life can be cruel T_T (sorry only iPod cam)
There is no way to adapt this to PS2 right^^

[kbdfr]

This time you're right, those are MX blacks
Mind posting a picture of the whole board?

[kbdfr]

[…] Well, next question, what keyboard am I supposed to buy? […]

Hey folks, another one getting hooked up

[Masterchief79]

Hey,
'course not, here are some digicam pics, but beware this thing is REALLY old (note: F13-F16 )
Also found a sh*tload of old keyboards, Cherry G83 etc but nothing mechanical in sight. (Why do we have more than 20 keyboards at home?)

[damorgue]

interesting layout, especially for being so old. They compressed keys in there everywhere but still chose to use a huge space bar

Hook it up to a teensy and you'll have it programmable too.

[Findecanor]

Looks like the exact same layout as a Wyse ASCII keyboard, for a text terminal. There are probably several other terminals that have the same layout, or very close to it.

Interesting key caps. The shape looks the same as Cherry's own caps, but the font is different. Could we get a picture of the inside of a key cap?

[JBert]

Hey,
'course not, here are some digicam pics, but beware this thing is REALLY old (note: F13-F16 )

Do I spot a diode in there? If so, the keyboard might even be NKRO, at least if the controller was made properly. Only getting it to work with USB will be some hassle, we don't know yet what protocol it talks to the terminal or computer it belonged to.

Certainly a keeper if you want to invest somewhat and keep it original. Oh, and it might need some cleaning...

[Masterchief79]

Hey thanks guys,
the whole terminal unit is still working if that helps, I think my father still uses it for testing sometimes. So, I hope I can use the keyboard as we don't have another one with this interface.^^
If you adapt that thing to USB, won't that cause the usual USB latency "problem" we were actually glad to get rid of with a mechanical PS2 keyboard? Or does that only apply to non-mechanical keyboards and doesn't have something to do with the USB interface?

So, going to take closer photos now... Gimme 5 minutes.

PS@cleaning: Sure, I mean this thing is nearly as old as I am, but with spiritus you can get it as good as new.

[Findecanor]

Thanks for the pictures. Oh, these keys are not even made by Cherry. When I look more closely, I see that the edges are actually sharper than Cherry's keys.

[Masterchief79]

Just opened the case. Damn, look at this baby Solid black eloxated aluminium (?) base and the electronics - see for yourself.
Btw powered up the terminal, keyboard working perfectly althouhh the layout is really something you have to get used to.

The information on the PCB is interesting, the keyboard gets a straight 12V input, whereas USB gets +5V i believe? Adapting this will require an own PCB with voltage regulators etc, and maybe I will have to program my own microprocessor to convert the information sent by the keyboard. Well, challenge accepted, I always wanted to do this on my own Would be fun to develop a PCB.

[Soarer]

Yeah, looks like fun! BTW, Paranoid has one of those too.

[Masterchief79]

Nice link, could be helpful, thanks