Re: .DSK Image does not work on real machine, but, works fine in an Emulator

[olcott <olcott@qwest.net>]

I am not sure, but, I think that the .DSK
image is already in DOS order, since
the original software was from a DOS
3.3 disk, and the .DSK file was created
with ADT for DOS 3.3. These are the
disks in question...

http://www.grin.net/~cturley/a2zine/Utils/AztecC_DOS33dsk.zip

Patrick Schaefer wrote:

> olcott schrieb:
>
> > The problem is this file will not run on a real Apple IIe,
> > but, does
> > run on an Apple IIe emulator. How could a DSK work on
> > an emulator, but, NOT, work on a real machine?
>
> The logical sector numbers do not follow the physical ones, there ist an
> interleave. DOS sector 1 is on physical sector 1, DOS 2 on phys. 7 and
> so on. This gives the computer some time to process the data before the
> next sector has moved towards the RW head.
>
> DOS 3.3 and ProDOS use different interleaving schemes.
>
> ADT expects the disk images to be in DOS order, that means using the DOS
> 3.3 interleave. That means block 1 is written on physical sector 1, bloc
> 2 on 7 and so on.
>
> NuLib creates image files in ProDOS order. If you download a *.SDK image
> and extract the *.dsk file, it won't work with ADT because the sectors
> are scrambled. However, the emulator programs can recognize the image
> format and therefore run both types. (They look at the catalog track)
>
> Some time ago I have written a small TurboPascal program for PCs that
> converts ProDOS order into DOS order. If you are interested, I can email
> you a copy, or I can upload it to a ftp server (which - is
> apple.cabi.net back?).
>
> Patrick