IBM 5150 Hardware Maintenance Manual page 81

This test is used to verify the 40 x 25 Alpha mode logic is
functioning on the Color/Graphics Monitor Adapter. The
border for the 40 x 25 character test should be white. Press
g
and
~
(Enter). The following should appear on
your Display:
40X25 DISPLAY
)*+,-./0123456789:
:(:)?OABCDEFGH!J~LM~OPI
*+,-./0123456789:
:(:)?OABCDEFGH!J~LMNOPQI
+,-.10123456789:
;<:)?OABCDEFGHIJ~LMNOPQR:
,-./0123456789:;(:)?OABCDEFGHIJKLMHOPQRS:
-./e123456789:;(:)?OABCDEFGHIJKLMHOPQRSTI
./B123456789:;(=)?OABCDEFGHIJKLMHOPQRSTUl
101234S6789:;(:)?OABCDEFGHIJKLMNOPQRSTUU~
B123456789:;(:)?OABCDEFGHIJKLMHOPQRSTUUW>
123456789:;(:)?OABCDEFGHIJKLMHOPQRSTUUWX~
IS THE SCREEN CORRECT? (YIN) -
~
­
, "
IS THE BORDER WHITE AND ARE ALL THE
CHARACTERS PRESENT AND COMPLETE?
NO
Replace your Color/Graphics Monitor Adapter. See
Section 3, "Removal/Replacement."
YES
500-10