deskthority

I did know from HaaTa's work that Nixdorf used magnetic valve switches on some of their keyboards. Wodan also owns one of these, they do show up occasionally.
Keyboard parts: top and bottom case, large isolation shield, metal plate with switches and lock module, PCB.
When I first pulled the keycaps for cleaning one switch came off and I thought I broke it. Wrong. It's supposed to come off, very serviceable and quite practical. This reminds me of first generation Honeywell hall effect or Tesla hall effect where the entire switch can be disassembled effortlessly, although here the switch is one closed part.
These magnetic valve switches are snap-on/off detachable on the fly without any soldering or screws (!). How can the switch be detachable and still function? The ferrite bead that makes the contact is soldered to the PCB, the actual switch itself is not!Rather the switch snaps firmly into holes on the metal plate, the plate sits on top of the PCB which has cutouts for the switches.

You can read what exactly a ferrite bead is here: https://en.wikipedia.org/wiki/Ferrite_bead
The slider shape is so strange because the spring is integrated in that round top white slider plastic achieving a smaller keyswitch housing and hence a thinner keyboard. Also the magnet had to be integrated into the slider base for the mechanism to work. Essentially the keycap mount is only a cross, it is possible to mount the keycaps the wrong way around.The area in front of the magnet with the recess is for the ferrite bead on the PCB.

Those little black open boxes on the PCB along the cutouts where the switch sits house the the ferrite beads in form of little wheels that actually move.
The metal plate with the snap on switches sits on top of the PCB with the ferrite beads at the holes on the PCB:
This is the slider pressed down through the hole in the PCB, notice the magnets.
Despite the slider making quite a bit contact with the housing due to it's strange shape, the switch is quite smooth in movement, nothing like Fujitsu leaf spring 3rd gen though. The switch is linear with no tactile event and no feedback. The keyboard does have a beeper / clicker that reads "VAC".
Top part of the case is light grey sturdy ABS, the date inside the case reads 9/86.
The Lebenslauf sticker on the PCB reads 9/7/87.
Just like everything about this keyboard, the key stabilization is also unusual and quite ineffective on the enter key while the spacebar is stabilized just fine.
The lock module in the metal plate is one part with five placeholders for the locks that is held in place by that metal bar. As usual I do not have the key. ;P Left of the lock section is the power slider switch, also quite low in profile.
This keyboard does not have any feet and is 3,5cm at the back and only 2,0cm low in profile at the front. It's 53cm across and 18cm wide on the side at 2085 grams. It has four round rubber pads that work quite well in keeping the keyboard in place.
The keycaps are thick doubleshots with a concave "scoop" like on the other Nixdorf CT** keyboards.
Concluding this it really makes me wonder why so few keyboards were built with this type of switch and if it was a cost factor how much more it actually cost to build something like this. Since this keyboard came with a Nixdorf terminal it wasn't cheap anyway. Like with the CT11 I could find almost nothing online about these Nixdorf terminals.

photos-f62/nixdorf-surprise-t13842.html?hilit=nixdorf

https://www.flickr.com/photos/triplehaa ... 7424/page1