If all eight pages are correct, press Y and Enter. If any page is filled with an incorrect number, press N and Enter co display the error message.

Light Pen Check

To check the function of a light pen connected to the color graphics adapter card, press 8 and then Enter. This test checks that a light pen connected to the color graphics adapter is performing accurately. When you select this check, you see these prompts:

Enter Y to start light pen check.Enter N to return to the menu.

If you do not have a light pen attached, press N and Enter. To begin the test, press Y and Enter. You see this prompt:

PLACE LIGHT PEN ON CENTER OF WHITE BLOCK

Touch the center of the white block on the screen with the light pen. When the light pen is correctly positioned, the block moves to another part of the screen for a second teat. After three successful tests, the check ends.

An error occurs if:

The light pen is not connected properly

You touch the screen at the wrong point

The light pen is malfunctioning

You do not touch the square within a certain amount of time (which is dependent on the current CPU speed).

D-20 Performing System Diagnostics