Inside Atari Dos provides some insight - and has the 2.0s source code.
Or even easier - just dump out DOS.SYS to a text file. Amazing that they used the program/workspace layout that they did, they probably could have saved 2 or 3 sectors by moving the embedded work areas to the end so that they weren't part of the loaded file.
I dumped out mine, there's a directory sector buried as well as FCB and other work areas.
So yeah, if you had a proper "virgin" copy of DOS, it might have a bunch of zeros in those areas or might have even been mastered from a "work" situation where there's remnants of a directory listing from something else.
(OK - I was doing this with DOS 2.5 but it's virtuall the same thing and I do suspect 2.0s would have the same bad habits)
Edited by Rybags, Sat May 12, 2018 7:09 AM.