I think it might have; I'm pretty sure the first mice were done by Engelbart's group at ARC (but I'm too lazy to check). ISTR that they were used in the MOAD. PARC's contribution to mice was the first decent mouse. I saw an ARC mouse at MIT (before we got our Altos), and it was both large, and not smooth to use; it was a medium-sized box (still one hand, though) with two large wheels (with axes 90 degrees apart), so moving it sideways, you had to drag the up/down sheel sideways (and vice versa). PARC'S design (the inventor is known; I've forgetten his name) with the large ball bearing, rotation of which was detected by two sensore, was _much_ better, and remained the standard until the invention of the optical mouse (which was superior because the ball mouse picked up dirt, and had to be cleaned out regularly). PARC's other big contribution was the whole network-centric computing model, with servers and workstations (the Alto). Hints of both of those existed before, but PARC's unified implementation of both (and in a way that made them cheap enough to deploy them widely) was a huge jump forward. Although 'personal computers' had a long (if now poorly remembered) history at that point (including the LINC, and ARC's station), the Alto showed what could be done when you added a bit-mapped display to which the CPU had direct access, and deployed a group of them in a network/server environment; having so much computing power available, on an individual basis, that you could 'light your cigar with computes' radcally changed everything. Noel