Hello!

  WP> is it possible to read atari recorded 5.25" disks
    > (160kB) with that?  it does use FAT filesystem but
    > don't know what about sector layout.

The 8-bit Atari 5.25" diskettes were FM encoded, so I doubt
a PC diskette drive would make much sense of them.  I
probably know some people who know the filesystem, or who
could find out. The general format was 40 tracks, 18 sectors
per track, 128 bytes per sector, single sided = 90Kb (this
is from my notes on the Atari 810 drive).

  CG> Assuming you mean Atari ST...
    >
    > I think they have the same format as on PC, so 160kB
    > should be 512 bytes per sector, 8 sectors per track,
    > 40 tracks, 1 side.

It's possible to plug a 5.25" drive into an ST, but they
normally used 3.5" drives.  The earliest models used single
sided disks (80 tracks x 9 sectors/track x 512 bytes/sector
x 1 head = 360Kb), most used double sided 'double density'
(80 x  9 x 512 x 2 =  720Kb) and a few used high density
(80 x 18 x 512 x 2 = 1440Kb) drives.  I understand it was
common to squeeze more sectors onto a disk, so there are
probably some diskettes out there with odd formats.

Hope this helps,
  - Andy Ball.