IBM PCjr Hardware Maintenance And Service page 230

The four blocks at the top of the screen represent
buttons on the attachable joystick.
1. Press one button on the attachable joystick, and
then release the button.
One of the blocks on the screen should become
smaller, and then return to its normal size.
2. Test all the joystick buttons. Each button should
affect one block on the screen.
DID EACH JOYSTICK BUTTON AFFECT ONE
BLOCK ON THE SCREEN AS DESCRIBED
ABOVE?
The attachable joystick is bad. Replace it.
If you have another attachable joystick to test,
go to page 2-1300-4. Otherwise, repeat
advanced POST and the advanced tests to
ensure that the IBM PCyr is operating
correctly.
The attachable joystick is operating correctly.
You have completed the Joystick PIC. If you
stOl have an unsolved problem, you should
seek technical assistance.
If you have another attachable joystick to test,
go to page 3-1300-4.
3-1300-8 Joystick