ADFs can be mounted easily. There are many packages for this on Aminet, for example FMS, XFS, DiskImage and many more.
For HDFs it is more difficult because they can be of different size. Diskimage.device can surely mount a HDF but you have to make an individual dosdriver for each size. You can take the dosdriver for a ADF and change heads = 1, sectors = 32 and cylinders to match the size of the hdf. Divide the size of the HDF in bytes by 512 and by 32 to get right number of cylinders.
