Algodoo

You should give some instruction on how to use these. It took me a while to figure out that I had to push the inputs with my drag tool. But I still don't know how I can activate TWO inputs with only one drag tool. Sure, I could make a rectangular box to use for pressing two inputs, but since you did not provide one in the scene, I assume there must be some other way to do it. Suggestions?

A button connected with the two buttons. Done!

Apologies for the vague description; A logic gate is a device mostly used in electrical machines to perform simple operations. In this scene, I have provided a mechanized version of some simple logic gates for lucidity.
You may view a more elaborate description here: http://en.wikipedia.org/wiki/Logic_gate

joon -- I understand what a logic gate is (I have worked with digital electronic circuits for many years), but the problem with this mechanical version is you cannot activate TWO inputs at the same time with only the drag tool. That is what I tried to clearly explain in my first comment, but I think you missed that. So, do you have a suggestion on how two inputs can be activated using only the drag tool?

Thanks

Sorry for the misunderstanding - I have updated the scene. A toggle mechanism has been added to each of the inputs, to make simulation easier. I hope this solves the problem.

Works good now!

Are these your own design, Joon? i must say the XOR gate is incredible. You have the great mind of a mechanical engineer!