Looking for knowledge/expertise on a mid 80s keyboard switch.

[Surpex]

Hey guys. I bought an Olympia Electronic Compact typewriter with the intention of recycling its switches for use in a hand wired board. The problem is, most of the switches have two pins on the bottom, just like MX switches, but some of the switches (like the space bar) have 4 pins. Does anyone know what the deal here is? Do I need to wire all 4 leads?

[andrewjoy]

It depends on the switch.

Do you have a multimeter ?

[2ter]

probably double action switches: two contacts for the normal keypress, the other two for when you press harder all the way down. is it marquardt butterfly switches (wiki/Marquardt_Butterfly)?
it should have mitsumi standard mechanical and the switches with 4 pins should be wiki/Mitsumi_standard_mechanical_double_action.

[Surpex]

It depends on the switch.

Do you have a multimeter ?

Unfortunately I don't have a multimeter. I should probably pick one up sometime, considering their utility, though.

.
it should have mitsumi standard mechanical and the switches with 4 pins should be wiki/Mitsumi_standard_mechanical_double_action.

This is exactly what they are! I disassembled the switch to check it out, and it definitely has two sets of contacts, and an extra, harder spring. Any suggestions on how I would wire this to a accommodate a modern keyboard?

[SpacemanToby]

You just have to figure out which two pins actuate on the first press and wire those. You can ignore the other two. I've hand wired a mitsumi typewriter conversion actually.

[2ter]

or you could wire it as if it would be two switches and actually take advantage of the switch.