Re: .DSK images with 40 tracks?

[steve@dosius.zzn.com (Dosius)]

Holger Picker <pickerh@uni-muenster.de> wrote in message news:<Pine.A41.4.44.0303112110440.81632-100000@zivunix.uni-muenster.de>...
> Hi,
> 
> well, at least it shouldn't be too much of a problem for an emulator to
> support 40 tracks. Whether you've got 30, 35, or 40 tracks, from the
> algorithm's point of view that's all the same. What's important though is
> how you would like to load and store a 40 track disk image. The standard
> .dsk image format (as well as .do or .po) only stores 35 tracks. Either you
> would have to come up with a new format or extend a previously existing one.
> (I'm sorry, I have not taken a deeper look into formats like 2em yet.) Could
> I ask you, please, which "real" disk drive supported a 40 track disk image?
> Were 40 tracks possible on a standard disk ][ drive? I know of a few AppleII
> emulators that are currently still under development, e.g. AppleWin,
> AppleOasis, Dapple, Kegs... If they do not support 40 tracks yet and 40
> tracks are considered standard, then 40 tracks should and could easily (IMO)
> be implemented.
> Kindest regards
> 
>   Holger

My Unidisk supports a 40-track DOS.  There are I/O errors reading the
disk in Mutandos (a 35-track DOS hack), but not in the DOS on the disk
(which was also a clone of DOS 3.3, and could read/write normal DOS
3.3 disks).

Disk ][, I cannot vouch for... :( I have no *working* disk ][
controller/drives.

I'd like to see an extension (160K DO?), maybe just a file-size check
on DSK images to autodetect 40-tracks.

-uso.