The ‘under’ in Undershield comes from this shield being mounted underneath the Arduino, unlike every other shield on the planet. Doing so allows use of a standard 0.100″-spaced prototype PCB ...

[Usmar A. Padow] put together an Arduino Uno, SD card, four line character LCD, and PS/2 keyboard. but he’s also included alternative options to go without an LCD screen by using a computer ...