The original Space Invaders?

[KeyDeep]

I recently came across a HI-TEK keyboard that looked very interesting. The keyboard only has passive components, and no date to truly identify its origin, but, from the switches layout, it looks like it was designed for the Apple IIc, around 1983. This was the time when HI-TEK launched the 725 switch series (space invaders).



I looked, but didn't find any previous pictures or any other literature for these switches.



The only place where the same switches are see is in the drawings of the European patent—EP0124206A1 “Low profile keyswitch”



They have no eyes and the contact opening is similar to the first generation "Gundam", but shorter. The switches are linear and smooth as butter. The keycap doesn't have the tabs to hold the switch, but just sits on top of the switch and can just be pulled out.



Interestingly, there are no stabilizers anywhere on this keyboard. The spacebar is missing, but there is no stabilizers even for the spacebar. I am not sure if this was a prototype board.

Any information or hints about these switches would be greatly appreciated.

[TheInverseKey]

Looking into this, it seems more like this might have been a one-off. The switches based on the slider does look different from the patent, as there is no protrusion coming from the top of the slider for the fourth post on the slider well. This might have been a stopgap switch between the 4-post switch and the later Gundam switch.