[Coco] Floppy format questions

David Ladd davidwladd at gmail.com
Mon Jun 17 13:40:17 EDT 2019

On Mon, Jun 17, 2019 at 11:42 AM Neil Cherry <ncherry at linuxha.com> wrote:

> I recall that OS9 had a unique (at least I thought so) format/layout
> for the floppy disk. Something odd about one of the tracks (I think).
> Can someone point me to a link with the information. I'm trying to
> setup a Gotek device with the correct floppy layout to start with.
> I do have a bunch of floppy drives (5 1/4 and 3 1/2 & 40 and 80 track)
> but it has been so long since I've used them. I'm betting they'll need
> more than a clean up.

PDF page 65 is the start of the information you might be looking for.

The thing is that the default sector count is the same.  18 (256 byte)
sectors per track.
Disk Basic is tracks 0-34 single sided only.
OS-9 can do double sided floppy disks and go up to 80 tracks or more
depending on what the actual drive itself can handle.

Disk Basic stores its special information on track 17 where as OS-9 stores
its volume information in LSN0 like most other OS's of the time did.

I hope this is helpful. :D

> Thanks
> --
> Linux Home Automation         Neil Cherry       ncherry at linuxha.com
> http://www.linuxha.com/                         Main site
> http://linuxha.blogspot.com/                    My HA Blog
> Author of:      Linux Smart Homes For Dummies
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