WYSIWYG came about when displays became bit-mapped graphics with a sufficient amount of dots per inch. Previously, displays used a character generator ROM chip

WYSIWYG came about when displays became bit-mapped graphics with a sufficient amount of dots per inch. Previously, displays used a character generator ROM chip which mapped ASCII onto one character. For a terminal I designed and built in those days, I used an off-the-shelf character generator chip which had a 5x7 font. The original IBM PC used a character generator.