[sebhc] H8D files and labels

Dave Dunfield dave06a at dunfield.com
Tue Mar 28 06:18:15 CST 2006

>I looked into my simulator and discovered/recalled that the sim
>actually accepts an image which is any integral number of
>tracks (ie: any multiple of 2560).
>So the simple size > or == test isn't suitable.
>The scheme would still work, as long as your comment field
>is not exactly 2560 bytes in size (which is a pretty big comment).
>I could have the H8D command automatically pad with an extra
>space if the supplied data is exactly this size.

Another approach, which is actually what ImageDisk does, would
be to have the tool automatically generate the first line of the
command in the format:

   H8D version.revision: dd/mm/yy hh:mm:ss
   (user supplied comment text follows as additional lines)

Which provides the visual information that this is an H8D file,
the version of the tool that created it (which allows for variations
in the specicification), and the date/time that it was created.

When loading this file, the first three characters must be "H8D"
for it to be a new format image. If this is likely to occur in an old
format image (I don't think so), you can further verify the 1st
line by insuring that it contains only space, 0-9, '.', '/' and ':'.

If the first three characters are "H8D". then you scan for the
^Z, record the offset, and validate the remainder of the file as
an integral number of tracks.


dave06a (at)    Dave Dunfield
dunfield (dot)  Firmware development services & tools: www.dunfield.com
com             Collector of vintage computing equipment:

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