A standard telephone keypad, with four rows of three keys each. The top row consists of 1, 2, and 3, with keys continuing down in order until the last row, which is usually *, 0, and #. Such a keypad ...

The PCB must be mounted floated, otherwise key presses don't work reliable. Connect pins 3 and 4 on connector P1 for 16-pin button mode. Smaller keypads with less pins may work, but are not tested.

Ask the publishers to restore access to 500,000+ books. An icon used to represent a menu that can be toggled by interacting with this icon. A line drawing of the Internet Archive headquarters building ...