Yesterday, I finally scanned in my entire Atari 400/800 OS Source Listing from 1982, complete with coffee stains. It's at 600dpi and it's a searchable PDF.
I've made it available for download on my Chimera blog, but be aware, it's over 400MB!
I hope it's useful.
Atari 400/800 Operating System Source Listing
Moderator: Atari Frog