Nov 26 2008
doctor half-adder
When illustrating basic Boolean logic, mechanical demonstrators are not only useful but fun. And score you geek points. Here’s a half-adder, which adds two binary digits to produce a sum and a carry, implemented in string, pegs and nuts.
(A full adder, which can also add in the carry digit from a previous adder, is just a bit more complicated. But would make a marvellous Heath-Robinson device in nuts and string.)
Propella also has several photos of the device’s construction on their stream and a whole set showing how to build a cardboard-based logic demonstrator.
(Dr. Adder has nothing to do with Boolean logic, but I could hardly pass up that title.)
Photo: “P1050370″ by Propella, CC-by 2.0. Taken 23 November 2008 with a Panasonic DMC-LS1.
