The red, green, and blue RCA connectors on your TV are component inputs, not composite. A composite input is a single RCA input and is usually yellow. The Hackvision outputs composite video. I’m very surprised that a TV does not have a composite input. I’m not sure what an SCART adapter is (is that European?).
So finally I tried downloading Asteroids to the Duemilanove and it won’t run. My instincts are it needs a different version of TVout. Please could someone advise me on exactly which version of TVout I need to get Asteroids to run?
If you have an Uno bootloader, I may have to provide a precompiled .hex file for Asteroids just as I did for Space Invaders/Pong. Something about having the Uno bootloader makes the older games not run when compiled with the newer IDEs.