The example files are images to try Graphic Workshop
out with. 

Example 1 -  two colour image file. This will be
             viewable on any card.

Example 2 -  sixteen colour image file. This will
             be viewable on EGA and VGA cards.

Example 3 -  256 colour image file. This will be
             viewable in its true colours on VGA 
             cards, although you'll be able to see
             it on EGA cards using colour approximation. 

To really see what dithering can do, print out
example one.