deskthority

Hello Guys,

after sliding hand over fist into the mechanical keyboard hobby, especially retro ones, i wanted to share with u what i found over the last months, starting with the board who started it all.
While at work, i spotted an old keyboard in the electronics scrap-pile and decided to take a closer look. While i didnt recognize the switches , it looked kinda interesting, so i decided to rescue it anyways. Overall in good condition, it turned out to be just telekom branded, since it was originally built by ericsson.
Sadlly, one of the keys was missing, but since iam planning to use it in TKL mode i will probably just steal one of the numpad ones.

The Board is really two seperate boards, held together by a thick and sturdy metal bar, connecting the two pieces. The "main" Keyboard is PS/2 , but the numpad is connected to the main board via an AT Style connector i think. After seperating the two Boards, and pulling of all the keycaps, to clean them in the washing machine, the board looked like this.
Since i plan to whiten the plastic with Hair - Bleach , i took the outer casing apart too.
naked PCB with switches looks like this: Single switch i desoldered from the numpad just to look at it. Notice the two wheels at the top right ? While i dont know what the first one does, the other one is a volume knob for setting the volume of the inbuilt speakers, that makes a sound for each keystroke (u can disable it completly)
While plugging it into my ps/2 capable machine, i noticed all the "normal" keys seemed to be working just fine, while the double F row (F13-F24), just where the same keys like the row under it.
Also, some of the special keys at the side didnt seem to register on the keytesting site i used.

I will probably post more vintage keyboard related stuff soon, i u guys have any more information / have any questions regarding this board, i would be happy to get some feedback.

Best Regards, and happy typing !

Nick

Interesting find! Look quite long even in the 'TKL' mode.

The Numpad being moveable to either side is a feature more keyboards should emulate.

switches in the wiki:
wiki/Ericsson_RMD_973_series

Nice find

Aye. Nice Ericsson “Unsaver”. You done good on your first find.

How do you like the switches? Haven't heard too much about these so far tbh

Reminds me of this thing.

Have a look there:
viewtopic.php?p=465335#p465335

TNT wrote: 02 Apr 2022, 23:24 How do you like the switches? Haven't heard too much about these so far tbh

i kinda like them to be honest, they need quite a bit of force to actuate , but travel is smooth overall. board feels really solid.

Slom wrote: 02 Apr 2022, 21:29 switches in the wiki:
wiki/Ericsson_RMD_973_series

Nice find

thank u !

paperWasp wrote: 02 Apr 2022, 19:40 Interesting find! Look quite long even in the 'TKL' mode.

it looks kinda big, but it feels quite perfect as a work board on my desk tbh, really looking forward to restoring it and making it white again

Info: Board is for Sale - just write me a PM - sold

I recently got my hands on one of these, but an Ericsson branded one, and probably a bit older since it has a traditional AT plug, which is causing a lot of woes.

A regular AT to USB converter does absolutely nothing, while a soarers XT/AT makes the locklights wake up, but nothing else, is that normal?

I guess whats next is to wire up a set 3 converter for terminals and see if that works, but is it known if any keyboard with a set 3 terminal protocol ever had locklights?

Aruberon wrote: 06 Dec 2022, 16:15 A regular AT to USB converter does absolutely nothing, while a soarers XT/AT makes the locklights wake up, but nothing else, is that normal?

To be honest, i dont know anymore. I used it the last time almost a year ago. Maybe you could ask user:
memberlist.php?mode=viewprofile&u=22697
about it , since he is the one who i sold the board to.

Aruberon wrote: 06 Dec 2022, 16:15 I guess whats next is to wire up a set 3 converter for terminals and see if that works, but is it known if any keyboard with a set 3 terminal protocol ever had locklights?

I personally dont know of such a board

Just let me tell you that while it is among the rarer boards and switches , i didnt really like the switches. Some were quite scratchy and bindy , probably due to the open design of the switches:
download/file.php?id=73260

But good luck on your journey. feel free to post pics or your progress here

I agree switch wise, they didnt feel particularly great out the box, but I havent had time to open it up and take a closer look, perhaps some cleaning and some dry teflon will make them nice.

As for the board, maybe its just cooked, considering yours, while being a ps/2 version was fine, looks wise mine is identical on the outside, minus the plug of course

Aruberon wrote: 06 Dec 2022, 19:03 I agree switch wise, they didnt feel particularly great out the box, but I havent had time to open it up and take a closer look, perhaps some cleaning and some dry teflon will make them nice.

I would love to hear a sound test on that once youve done it ! I recently got an ultrasonic aswell as a gift from my father and iam stoked to try it out on switches that need it !

Aruberon wrote: 06 Dec 2022, 19:03 As for the board, maybe its just cooked, considering yours, while being a ps/2 version was fine, looks wise mine is identical on the outside, minus the plug of course

Could be but Iam not knowledgeable enough to give any clues , sorry

So I opened it, and there is no visible issue with it, im getting good readings on the multimeter etc.
So it either speaks moonspeak, and considering its quite unusual with 0 documentation, thats a dead end, or its just mega cooked beyond salvation, it does after all have chips like an old 80s home computer, so they might just be no good etc.

Its effectively scrap, and will be treated like scrap, which is a shame.
However, while the switch might not be fantastic, it would be nice to have a working reference so im thinking about getting the numpad up and running instead.

It has no microcontroller of its own, so it would have to be handwired, the dummy switches will be replaced by normal switches as well, creating a 5x5 numpad, and with all keycaps being a uniform profile I can pick and choose from the board carcass.

For now the main board has been robbed of switches, they will get a good cleaning until the arduino arrives sometime next week.

Status update: It lives!

So after a decent bit of troubleshooting, my first handwire project was successful:
It looks like an absolute abomination, and reusing the original PCB as a bracket to hold the switched ment I had to drill out the traces manually so nothing would cross and activate when it shouldnt, this took longer to trouble shoot than expected, but the end result looks fantastic:

Before installation, all the switches were lubed with dry teflon lube, alas 3 switches died either during lubing or during the installation process as they are built like actual garbage, so as per request by guidemetothelight a soundtest will follow with lubed v unlubed switches installed on PCB with keycaps on.

Lastly, its currently set up as a keypad with some extra features: Ive never given a keypad layout much thought, if any of you have any good ideas for a 5x5 keypad layout let me know!

The Finale

The end is here, as the numpad is now actually operational, it ate a pro micro in the process but with the bootloader button installed, ideally this contraption will remain forever shut.


And as promised, sound test.
I think its pretty clear which is which, the sound and feel is much improved, they arent actually too bad in their lubed state.

https://soundcloud.com/dan-254739213/rmd973