IBM 5155 Manual To Operations page 93

Test 490
If you have an external display connected to your IDM
Portable Personal Computer, the sample screens shown
in test 500 apply to both displays. If your external
display is an IDM Color Display, and if the sample
screens are not the same, go to Test 9000.
The internal display in the IBM Portable Personal
Computer
will
not give a true representation of the
colors shown in Test 500. The colors will be displayed
as different shades of amber and black.
Continue with the next Test.
January 1984
Test 490-1