Toshiba Tecra A3 Maintenance Manual page 91

3. Tests and Diagnostics 3.12 Keyboard Test
Pressing a key also reveals that key's scan codes in the upper right hand corner of the screen.
When the key is depressed, its make code is displayed. When the key is released, the break code
is shown.
3-16 Tecra A3/S2 Series Maintenance Manual