Here is my demo code from today (some of the comments may be
illustrative):
http://www.eng.utah.edu/~agreer/dualport_vga_test_demo.zip

The smiley face image (xess format) is here:
http://www.eng.utah.edu/~agreer/smiley_512x384.xes

The image conversion software from xess.com is available here:
http://xess.com/downloads/img2xes.zip