Difference Engine Simulator

Each of the boxes represents a digit. In real hardware, this is a wheel with the labels 0..9 (no error checking in the software simulator!).
Each row of boxes represents a number. In real hardware, there is a "carry" mechanism: when a wheel transitions from 9 to 0, it steps its left neighbour wheel (try pressing "+1" on some row several times).
When the "crank" is operated, the number at a lower row is added to the number right above it, which is then added to the number right above it, and so on (with carry).
Normal operation: manually set all wheels in the right position (here: click a box and enter a digit), and then keep on "cranking" to produce a stream of numbers (in the top row).
Press on of the "example" buttons for sample setups (note: for negative number, use the 10's complement, i.e. substract from 1000).