I would see if you can find one of these keypad drivers. They are obsolete, and have become expensive, but sometimes you can find them.
http://www.fairchildsemi.com/pf/MM/MM74C922.html
JImmy
I would see if you can find one of these keypad drivers. They are obsolete, and have become expensive, but sometimes you can find them.
http://www.fairchildsemi.com/pf/MM/MM74C922.html
JImmy