- hardlinks, and detect hardlinks by examining directory
- create image if not found
- read directories
- mount option which prohibits more than 144 dir entries
- 40track d64: enhance detection by looking for zero blocks in BAM
- d71 - upon mount make a validate run through the disk and check which sectors on track 53 can be deallocated (because they are not used)
- interleave has to be done with a table for each disk type
  + D64: file sector interleave 10, dir sector interleave 3
  + D71: file sector interleave 6,  dir sector interleave 3
  + D8?: interleave 1
  + interleave explained in disk.txt
- document commodore type type to unix file permissions mapping
