49440
You're doing it right.
I was learning how to make stuff on the atari 2600 when this compo appeared. I noticed how loud, harsh and not quite pitch accurate some of the sounds were on this chip, which is just what is needed here..!
Here's the .bin for it;
http://2a03.free.fr/dl.php?file=4612
Unfortunately the last 8 or so patterns got lost in the pattern limit :(