The valid keystrokes for the different tests are:

'1'	: Loads textures into the Texture Cache via a Heap method.
'2'	: Loads textures into the Texture Cache via a System Memory
	  method.
'3'	: Loads textures into the Texture Cache via a Direct Frame
	  Buffer Access method.
'4'	: Shows how to use LUT4 textures.
'8'	: Shows how to use LUT8 textures.
'L','l'	: Draws lines.
'T','t'	: Shows some of the many possible texture mapping types.
'U','u'	: Shows more concepts of texture mapping.
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