I told myself I would stay out of this thread. Steve jobs first got the idea for the mouse after visting Xerox and seeing the mouse being used by PARC, which was created by Engelbart. He then hired a outside group called Hovey-Kelley, to design and build the perfect mouse. They made hundreds of variations, field tested them all, came back to apple with the mouse that worked best, it was Engelbert's design with a button placed on top of it. But it was not until 1987 and ibm and windows creating the first ps/2 connection that allowed for a the 2 button mouse, did anyone find a point to the mouse. The mouse on the lisa computer was pretty, but really did not do anything. Most people did not bother to plug in the mouse, because it was kind of hard to use.