i have made an "electronic" 8bit calculator (not "mechanical" calculator) with the Beta demo of "Little big planet" (a new PS3 game with an editor for create). it do decimal/binary conversions and it can do Add and Sub. There are probably more simple solutions for calculator machine but i was more interested by this "electronic" solution for the fun
computation take clearly less that a half second this calculator use: - 610 magnetic switches - 500 Wires - 430 pistons - 70 emitters and others stuff...
I have made this machine only with the Beta demo, one month before the commercial release of the game (look the date of the video) in approximately one week.
Level called "Little Big Calculator" my PSN is Upsilandre