Apple Personal LaserWriter300 - Manual (Page 20)

3. Insert a stack of paper that fits below the top edge of
the paper bracket inside the cassette.
4. Slide the cassette into the printer.
To remove the cassette to refill it, grasp it and pull firmly
straight out.
Push firmly to make sure
the cassette is in place.
Make sure paper fits under
the corner brackets.
Insert paper this end first.
Corner bracket
12 Chapter 2: Adding Toner and Paper