  addlw 0x0C0                ;  Set Carry if 0x041-0x046 ("A" to "F")
  btfss  STATUS, C
  addlw  7                   ;  If Carry Not Set, 0x030-0x039 ("0" to "9")
                             ;   To Offset from A-F to 0-9
  addlw  9                   ;  Value is now 0-F
