I wasted a couple hours debugging a Kensington Pocket Keypad I had purchased to work with a 3D program I’m using. I use ancient Model M keyboards on all my PCs, specifically the 84-key Space Saver design that lacks a numpad. Geeky notes follow.
PC Keyboard Scan Codes
Every key on a IBM PC-style keyboard has a unique identifier called a “scan code”. For complex applications with a lot of functions, it’s not uncommon to use the numeric keypad for special uses. So while you might think typing a “9” on the numpad or the top row of keys doesn’t really make a difference, they are two distinct keys. Each key has a unique scan code, and software can be written to take advantage of that.
I used a nifty utility called ScanCode Show to tell me what scancodes were being sent by the Kensington compared to the Targus keypad I just picked up. The Targus (model AKP01US, wireless) sent the correct codes. The Kensington sent the codes for the other number buttons at the top row of the keyboard. Functionally, this is OK most of the time, but it is 100% useless for what I need it to do. Back it goes!
It’s really too bad, because otherwise it’s a very attractive, compact, good-feeling keypad with extra USB ports.