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Re: DSK format specification



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In article <XPmcnegnDrhixo-iXTWJkw@comcast.com>,
Bill Garber <willy46pa@comcast.net> wrote:
>"Andy McFadden" <fadden@fadden.com> wrote in message
>news:jfrQa.1595$dk4.78076@typhoon.sonic.net...
>> In comp.sys.apple2 Michael Pender <mpender@hotmail.com> wrote:
>
>> I should probably point out that you get most of that with ShrinkIt.
>> Empty blocks can be "zapped" with ProDOS 8 ShrinkIt, and then compress
>> down to nothing.  Date and volume name info are stored.  It's always
>> ProDOS-ordered, so there's no confusion.  There's a widely-tested utility
>> for creating and unpacking images on the Apple II, and (if I may say so
>> myself) solid support under pretty much every other platform via NuLib2.
>
>But even SHK files give us trouble as Andy and I found out earlier
>today, or was that yesterday as of now, anyway, apparently people
>have uploaded files thru a browser or were not posted to the folder
>properly on GROUND and the files ended up with an HTML header.
>128 bytes of it. Once removed the file is fine, but does not work without
>taking off the header.

That would most likely be a Binary II header, not an "HTML header" (no such
thing exists in the context of Apple II archives).  Apple II files residing
in binary form on non-Apple II systems should have them.  ShrinkIt reads
right through them.  NuLib can read them as well:

nulib bx foo.bxy

produces FOO.SHK (or FOO.SDK if it's a disk image), which can be passed back
into NuLib to decompress.

There are other methods for stripping a Binary II header off a file; for
instance, you could use dd under Linux, Cygwin, Mac OS X, etc. to start
copying a file from position 128 instead of position 0.

  _/_   Scott Alfter
 / v \  salfter@salfter.dyndns.org
(IIGS(  http://alfter.us            Top-posting!
 \_^_/  pkill -9 /bin/laden         >What is the most annoying thing on Usenet?

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