[sebhc] h17 and h8d disk images

Mark Garlanger garlangr at verizon.net
Wed Sep 1 21:01:03 CDT 2004

"Dan Lanciani" <ddl-cctech at danlan.com> wrote:
> "Barry Watzman" <Watzman at neo.rr.com> wrote:
> |Only by recording BOTH of these -- they physical layout AND the logical
> |layout (the numbers in the header) would it be possible to physically
> |reproduce a physically correct image of the diskette.
> If you *do* have to worry about non-standard formats used in copy 
> protection
> schemes then merely recording that information is far from sufficient to
> reproduce the disk.  Using funny sector/track numbers and positions got 
> old
> within months of its introduction.  To be able to make an accurate copy 
> you
> need to record both the data and the *clock* bits in the FM or MFM stream 
> along
> with the timing relationship to the index hole.  This is because people 
> learned
> to embed headers within data areas and play games with non-standard 
> address
> marks.  Even with the data and clock bits recorded you might not be able 
> to
> make a reliable copy if you don't know how to recompute the correct 
> precomp
> shifts.

Did anyone exactly make copy-protected software for the H89 in either HDOS 
CP/M? I had quite a bit of software for the H89, but don't remember one 
that used copy-protection. (I do remember Apple II games having it and alot
of IBM PC software had it.)


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