Can you be a little more specific? I don't see how a 2-d function (and I mean function, I've never done much polar or diff. eq. stuff) could be grayscale. It's simple to write a tsr using the user interrupt to display a background picture in grayscale, if all you're after is something cool looking (and it does look neat). >Grayscale graphing would be nice. Anyone got any ideas on that