PURPOSE: To allow a user to see characters or patterns written on a card-shaped memory medium only when said memory means is loaded in a correct way, by forming a window at the corner of a container for said memory means.

CONSTITUTION: A card-shaped memory container 1 is attached rotatably and in a free loadable/reloadable way to a base 2 at a single side by means of a hinge. A window 3 is formed at a corner on the surface of the container 1 to see the program names or patterns written on said memory medium when this memory means is loaded in a normal way, i.e., the contact of the memory medium can abut on a contact pin attached to the base 2. In such a constitution, the program names written on the card surface can be viewed through the window 3 by opening the container 1, then loading the card memory medium in a prescribed direction.