                 DROP SHADOW TEST 

This is a crucial test for 240p upscan converters.
It displays a simple sprite shadow (32x32 pixels)
against a background, but the shadow is shown only
on each other frame. On a CRT this achieves a
transparency effect, since you are watching a 30hz
(25Hz) shadow on a 60hz (50hz) signal. No 
background detail should be lost and the shadow 
should be visible. 

The user can toggle the frame used to draw the
shadow with button #GCL#G. Backgrounds can be
switched with the #GA#G button and button #GCR#G
toggles sprites.