On Tue, 10 Aug 2004, Dwight K. Elvey wrote:
> There is a format that has been used with the H8/89
> hard sectored disk called SVD. I like it in some ways but not
> in others.
Do you have a good description of the SVD format somewhere? I'm sure it
has some useful information.
> The issue of reading the actual file from an image and placing
> that into a file is another issue. Each disk system uses a
> different directory structure and allocation method. How this
> could be simply encoded into the image files is more than I'd like to
> think about unless one would just settle for a textual description
> in the comment space.
The idea is to make a representation of the raw bytes of the media,
segregated with markups into tracks, sectors, etc. (or whatever is
applicable for the particular media).
See my paper here for an idea of what I'm talking about:
http://www.vintage.org/content.php?id=004
Scroll down about halfway to the inset with the HTML-looking markup stuff.
> As an example, the H8/89 hard sectored disk have a volume number
> encoded in the header field ( that isn't part of the data ). The
> directory and allocation tables are pointed to by specific locations
> on track 0. They are not at specific locations.
All that data would be preserved in the format that I have in mind, since
the raw bytes of the disk would be preserved.
> Other issues that might be a problem are things like the actual encoding
> methods used. Not all data is in nice 8 bit chunks ( my Nicolet does
> 20 bit chunks ). Inter leaving is usually not a great issue since
> it often only effects speed but it might be important.
Exactly. This is something that will be addressed in the standard.
You should be able to specify the byte/word length, interleave, encoding
format, etc.
--
Sellam Ismail Vintage Computer Festival
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Received on Tue Aug 10 2004 - 22:02:57 BST