Nixie Black

"Typically connected to the Nixdorf 8870 Quattro microcomputers of the time, in addition to the CT08 and CT11 keyboards, the CT06/07 looked quite similar in design scheme to other Nixdorf branded keyboards at the time, but instead featured a special kind of Cherry MX switch that was only since been almost entirely seen in the likes of these specific Nixdorf branded keyboards. (There is one instance of these being found in CT11s, linked at the end of this article.) If you haven’t been read this bedtime story before, this certainly seems like a baffling choice as currently Cherry only does their OEM sets of switches and never produces custom switches for anyone. Rest assured, Cherry back in the day was not shy about doing custom switch designs, schemes, or layouts for particular companies, with one of the other most ‘common’ famous examples being the Cherry MX Olympia Whites. Moving back to the CT06/07, these particular Cherry MX style switches appeared to be just Cherry MX Blacks that would have been produced at that time, but with a translucent, milky top housing rather than an all-black getup. However, these vintage switches are particularly unique in that they contained the diodes for the PCB inside of the switches rather than in a through-hole fashion soldered underneath the switch. Interestingly as well, one of these boards specifically even came mounted with black o-rings underneath each of the keys which didn’t happen often at the time for mechanical switches. The final remaining point of interest regarding the Nixdorf Black switches, commonly now shorted as ‘Nixies’, was that in addition to a full layout of these on the CT06/07, every board came with a differently weighted and colored spacebar switch like a lot of other vintage keyboards at the time. Rather than the famous black color, these one-per-board switches featured a white stem as well as a significantly heavier spring weight than the black Nixies." - Theremingoat