Atari 800xl "translator disk"?

[David Betz]

I have an Atari 800xl and a couple of 1050 disk drives. I also have  
two copies of the M.U.L.E. game on disk. Unfortunately, I can't get  
either to boot on the 800xl. I suspect that these are older games that  
were written for the 400/800 and may need the "translator disk" that  
allowed the 800xl to run games written for the older machines. Does  
anyone know where I could obtain a copy of this translator disk?

Thanks!
David Betz