On Sep 20, 2015, at 8:55 PM, Jerome H. Fine
<jhfinedp3k at compsys.to> wrote:
  ... 
 I used the above example when I created a CD which had files to be used
 with RT-11 in addition to being a normal CD under Windows.  I found that
 for a normal CD under Windows, sectors 0 to 15 (hard disk blocks 0 to 63)
 on the CD were empty.  I don't know if that area is reserved for boot code
 under Windows when the CD is bootable, but my goal did not require the
 CD to be bootable under Windows. 
I did something similar a long time ago, when some people at DEC were working to create an
"Everything for RSTS/E" CD (similar, I think, to what was done for VMS at that
time).  In my utility "rstsflx" I added a mode to produce a split structure
somewhat like what you mentioned, but simpler.  The RSTS file system looked like a CD
file, and the rest of the CD looked like allocated space to the RSTS file system.
I heard rumors that the CD it was meant for was created, but I never actually saw one.
        paul