ref: d743498615c8e3b3f09578b924a96ac4faea85df
parent: dd752bbf3a1d7bec2f2c79eaed60277a1a4d53fe
author: phil9 <telephil9@gmail.com>
date: Mon Dec 27 19:18:21 EST 2021
implement edition value under the cursor can be modified by entering valid hex digits.