Re: P00-format + new D-format

From: Marko Mäkelä (
Date: 1998-10-10 18:55:59

On Sat, 10 Oct 1998, Levente Harsfalvi wrote:

> What about a flexible disk image format, with variable parameters?
> I mean, if it contained a header, from which the programs could decide
> if the image contains X or Y tracks/sectors etc.

This is a good idea, although I think that the geometry can be determined
from the image file size.  I see no reason in inventing disk images with
completely different geometry; as André pointed out, you should use the
underlying file system unless you are using a disk image that originates
from a real Commodore (8050, 8250, 8280, 4040, 1541, 1571, 1581, maybe CMD
FD-2000 and FD-4000, maybe also the D9060 and D9090 hard disks).

> Maybe, some presets could be used instead/besides the tracks/sectors etc.
> datas, telling if the image is a plain 1541, 1551, 2031, 8050, 8250, SFD1001
> etc. image. And the other parameter-definitions could modify this, like it is
> seen in reality (I mean, 1541 disk with 41 tracks, 1541 disk stored in
> GCR data and etc...). This could be done with storing the preset type,
> and registering if one or another modifier is valid and must override
> the appropriate setting given by the preset. (So in fact, this
> format is as flexible as using no presets at all, but can be handled
> easier).

These are good ideas.  I think that also the plain raw disk image format
should be supported; the tools shouldn't require this header to be
present.  BTW, the cbmconvert package by me coudl be a good starting point
for supporting different disk images.

Your description of emulating 1541 hardware was interesting.  I gave up
the idea even before considering such optimizations.


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