I agree. Hexadecimal entry would be preferred. If you are using any 4x4 or 4x5 keypad then each hex digit could be assigned a key and data entry would be a lot easier.

If you're really going to be entering 1's and 0's that's binary input. It doesn't require a keyboard. Just two buttons--one button for "1" and another button for "0". Of course, if you're entering 40 lines of 40 binary digits that means you're going to have to enter 1600 binary digits! That's a lot of "typing" and lots of opportunity for errors in data entry.

Go with hex instead!

Regards,
Craig Steiner