Re: DSK format specification

[Andy McFadden <fadden@fadden.com>]

In comp.sys.apple2 Michael Pender <mpender@hotmail.com> wrote:
> I think its time for a new DSK format that includes at least these features:
> -  support for 256 byte, 512 byte, and 1024 byte blocks
> -  a used-block map for supporting sparse disks
> -  other information such as the date the media was formatted, original name
> of the volume, etc.
> 
> The new format would be a super-set of other formats and the embedded
> information would help eliminate many of the problems of dealing with
> archived media from 4+ different operating systems (DOS 3.3, ProDOS, Pascal,
> CP/M, etc.)  However, I haven't spent much time thinking about support for
> copy-protected disks of the era.  I'm not sure there is a good way to deal
> with those.


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.

The only copy-protected disks worth saving are 5.25", for which we have
NIB (though see the recent discussion about things NIB doesn't have).
Preserving copy-protected 3.5" disks doesn't seem to be all that important
to people.

Rather than finding an uber-format that handles everything, I think
it's best to reduce as many formats as possible down to a single approach.
Resolving the DOS vs. ProDOS ordering ambiguity can either be done like
2MG does it (adding a flag to support both and requiring all programs
to handle them) or by simply defining things to be one way, and letting
format conversion programs take the burden of swapping sectors around.

-- 
Send mail to fadden@fadden.com (Andy McFadden) - http://www.fadden.com/
CD-Recordable FAQ - http://www.cdrfaq.org/
CiderPress Apple II archive utility for Windows - http://www.faddensoft.com/
Fight Internet Spam - http://spam.abuse.net/spam/ & http://spamcop.net/