Hi All 😀

Ontrack Disk Manager mangles disk partitions in a way that prevents Linux from seeing where a partition starts. So there is no easy way to mount a FAT32 partition on a OTDM disk. I searched for a way for mounting these partitions on Linux but found nothing on the internet. I discovered this method myself so I thought I should document it here.

- Ontrack Disk Manager 9.57 from Phil's Computer Lab: https://www.philscomputerlab.com/ontrack-disk-manager.html
- Install Ontrack Disk Manager on the retro computer and create and format a single big partition as FAT32 and install os on it.
- Move the disk to a Linux computer and search for the start of the FAT32 partition by opening the disk (in this example: /dev/sde1) to a hex editor:

1hexdump -C /dev/sde1 | less

- Search for FAT32 id string "MSWIN4". In my case the first occurrence of the "MSWIN4" string was not the beginning of the partition but the second one was.
- Count three bytes backwards from the beginning of the "MSWIN4" string and take a note of that hex address. In my case it was: 0xEA03 and the beginning of the partition was: 0xEA00.
- Convert the address to decimal (0xEA00 = 59904) and mount the partition using this number as offset to the start of the FAT32 partition:

1mount -t vfat -o offset=59904 /dev/sde1 /mnt/

Done 😀 Now you can copy stuff to / from the partition and move the disk back to your retro DOS - machine.

Further reading:
https://wiki.osdev.org/FAT#FAT_32
https://en.wikipedia.org/wiki/Design_of_the_FAT_file_system