IBM Personal Computer AT Manual To Operations page 346

6
Did all the buttons show pressed and released and
did the joysticks or paddles move in each
direction?
PRESS AND RELEASE ALL BUTTONS
EXERCISE ALL JOYSTICKS/PADDLES
AND PRESS ANY KEY WHEN DONE
DID ALL BUTTONS SHOW PRESSED AND
RELEASED. AND DID ALL JOYSTICKS
OR PADDLES MOVE IN EACH DIRECTION?
(Y/N)
?
YES Press Y then press Enter
(...-J)
and refer
to the screen for the next test.
NO Have your system unit serviced. Be sure
your Key Lock key is with your system
unit.
1300-6 Test