https://exxoshost.co.uk/downloads/Atari_HD_File_Sytem_Reference_Guide.pdf3.5 TOS Maximum number of partitions
It is difficult to find information about this limit in the literature. However it seems that the maximum
number of Hard Disk partitions that can be “installed” (or I should say “mounted”) on a system is 14.
The standard Atari File Selector only goes from letter A to P (2 letters for the floppy disks, and 14
letters for the hard disks). This limitation is clearly indicated in the Atari AHDI 3.00 Release notes (in
the PUN section page 15) where the MAXUNITS parameter is defined as 16 (including floppy drive A:
and B:). It does not seem that new releases of TOS have changed this limit.
Note that this maximum limit is to share for all the connected drive. This also implies also that the
maximum number of partitions for one drive is 14.
With BigDOS the limit is uplifted to 29 (C – Z except U) + 1-6.
With Mint the limit is 23 partitions (C – Z except U).