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.