In 1982, Hewlett Packard's HP-75 incorporated a 1-line text display, an alphanumeric keyboard, BASIC language and some basic PDA abilities.
From the en.wikipedia.org
Simple CAPTCHA systems which display alphanumeric characters have proven vulnerable to optical character recognition software but those that scramble the characters appear to be far more effective.
From the en.wikipedia.org
Alphanumeric pagers are essentially modified versions of numeric pagers with sophisticated display to accommodate text.