forum.defence-force.org

Hi all,
I'm trying to write FT-DOS on a real 3" disk for someone that bought a Jasmin drive, but I keep having write errors after a while.

I noticed the DSK file is 513Kb big. Isn't it too much for a 3" disk?
Or is it just my real disks, or drive, that are getting old?

Hi,

The usable size is 256 bytes * 17 sectors * 41 Tracks * 2 sides = 356 864 bytes.

But, a MFM_DISK image use 256 bytes for the header and 6400 bytes per track instead of 17*256 = 4352.
256 + 6400 * 41 *2 = 525 056 bytes or about 513Ko

Ah, thanks a lot for this! Brillant explanation. So it should be fine, I'll keep trying with other disks...

BTW I tried to test the faulty disk with my Jasmin 2 but it began smoking after 30 seconds of unsuccessful attempts to boot...
I really know why I prefer tapes