[NiLuJe]

@frostschutz: I was vaguely wondering if we could somewhat get rid of the delay= shenanigans by plotting a pixel (say, the last one on the bottom right) in a specific sentinel color (say, 0xEE), then checking regularly if it hadn't been cleared to white (as the very bottom-right corner pixel ought to be white pretty much everywhere except the USB screen), which would indicate that the page has been redrawn...