punch card programming

Use 3x5 index cards, a sharpie, and a webcam to program a simple machine.

The index card is oriented vertically with the red line to the left. This
provides 10 columns relative to the blue lines and leaves the far left and
and right parts of the card for comments. Each card has 8 rows spaced
uniformly, corresponding to 8 instructions of 10 bits each.

The machine is a simple accumulator machine. It only provides a few basic
operations, 8 registers, and I/O. The registers and operations work with
arbitrary precision integers.