In order to differentiate being the RETURN and ENTER keys on an Apple III, you need to redefine the keyboard layout table to command the console driver to return two bytes with every request for a character. While we cannot obtain a document of the format of the keyboard part of the driver, the diagram on page 165 in conjunction with the diagram on page 135 of the Standard Device Drivers manual shows what information is returned in the two byte mode. The ENTER key will return $0D just like RETURN but the second byte will have bit 7 set. Beware that after enabling the double byte read from Business BASIC, an invokable module is required for text. Two GET statements won't work.