With this you can HEX-keypad in style, you'll no longer have to slave away entering HEX-digits using your standard base 10 numpad! This is the deluxe keypad belonging to the RC-ONE computer, a KIM-1 replica, so you'll also have the additional keys found on the classic computer designed by the late Chuck Peddle. MOS was famously bought up by a somewhat unknown typewriter-manufacturer named Commodore, so the computer was also later rebranded as the Commodore KIM-1 which shares the key-layout I've used!

This module plugs onto that keypad-module, see my other shared projects for the actual keypad-part. What this does is plug into the same connector ordinarily used to connect to the RC-ONE computer, through the modern miracle of the Arduino Pro Micro the keypad'll now work on your modern PC as a USB-keyboard.

If you want to continue using the keypad with the RC-ONE computer you should install a female 2x8 pin female header on the bottom of the module, that way you can insert and remove it as needed. If you only intend to use it as a HEX-keypad connected to a modern PC, I recommend just using soldering it straight on with header pins cut down to size afterwards - in which case you should not inistall the LED on the keypad itself (the holes for it can be soldered with header pins for added support).