Q34: does anyone know if the gnome calculus(A&EG) was ever updated, and Q35: can u dual wield them?
A34: It hasn't been updated.
A35: It's an oversized sling. As with slings, you can fire, but not load, a Gnome Calculus with one hand. Therefore, if you had two pre-loaded Gnome Calculi, you could use the TWF rules to make two attacks. You'd then either have to reload as per the reloading rules for slings (which means two move actions to reload both) or pick up two new Gnome Calculi to be able to attack with the TWF rules in the following round.