Epson 20 - Manual (Page 153)

You see these messages on the screen:
KEYBOARD CHECK
Press ESC followed by ENTER to exit.
Press END followed by ENTER if screen and
keyboard do not match.
If all the keys function correctly and match the characters displayed,
press
E
SC
and then Enter.
If all the keys function, but the characters displayed do not match the
keys, press E
SC
and then Enter. Then reselect the keyboard test
from the DEVICE LIST, and check that you selected the correct
keyboard layout. You can find diagrams of all the international
keyboard layouts in the MS-DOS manual.
If any key is incorrect, press End and Enter. Make a copy of the
error code and message, or print them out, and contact your Epson
dealer or service center.
Monochrome Display Adapter and CRT Check
Use this option to verify the operation of a monochrome display
adapter, VGA, or EGA attached to a monchrome monitor. This test
includes several checks that allow you to identify particular problems
related to the monochrome display. To run this check, the monitor
switch on the front panel must be set for a monochrome monitor.
Performing
System Diagnostics C-9