Keyboard – How can I enter hexadecimal quickly?

I am a computer science student and often have to enter hexadecimal strings manually. However, entering a combination of numbers and ABCDEF is so slow, whether I use the number series or the keypad.

One idea I had was perhaps that there are special hexadecimal keyboards. However, a quick search does not take place everywhere.

So yes, how can you enter hexadecimal quickly?