Patent US 3,974,493

In a keyboard entry word processing system, text is stored in a recirculating refresh memory along with a carriage return code at the end of each line. The text is displayed on a CRT screen. A cursor symbol, also displayed on the screen, may be moved by keyboard control to designate a particular character position on the screen where editing is to occur. When the cursor is within the field of displayed text, characters may be edited at the location in memory corresponding to the location of the cursor on the screen. When the cursor is outside the field of displayed text, the cursor is first "found" by altering the refresh memory to provide a new memory location corresponding to the cursor location, and then editing is performed at the new memory location.