[simonh]

Modern computer operating systems won't let you arbitrarily switch pixels on the screen on or off, so you'd need to either write a program that uses a GUI library to create a window, controls, etc, or generate an image file you can open in a viewer.

For Python, matplotlib(1) will let you generate plots and graphs, including simple x/y graphs, or you could use the built-in TkInter(2) library to do a simple GUI with a drawing canvas.

(1)http://www.labri.fr/perso/nrougier/teaching/matplotlib/ (2) http://www.python-course.eu/tkinter_canvas.php

[jeffwass]

Thanks. The drawing canvas seems just what I'm looking for.

(And yeah, I totally get I can't just flip arbitrary screen screen pixels, any more than I can access arbitrary system memory like I used to be able to with PEEK and POKE).