When an image file is made with DiskDupe the entire disk is read in
and the image file contains only the information from the tracks that
have data on the master (the "Track Range Data" setting has no effect
when disks are read).
It is important that the master be "clean" (formatted with format
set to "Always" under "Options" in DiskDupe or formatted from Dos
using the /u switch) before files are copied to it so that there is no
old data on the final tracks of the disk.
When any image is used for copying and the
"Track Range" is set to
"Data" only the tracks that have data on the master are copied and
verified on the destination disk. If DiskDupe has trouble reading any
of the tracks that it is copying to then it will try to reformat the
disk from the bad track through the last data track of the disk, so a
poorly formatted disk is still usable. By choosing "Track Range Data"
DiskDupe is forced to look at only the data tracks of the destination
disk (to speed up the copying process) so any errors in the part of
the disk beyond this data will not be caught. The disk will perfectly
readable from Dos because all of the data tracks have been copied and
verified by our software (provided that "Verify" is set to "Always" in
the "Options" menu), but it may not be readable from our software if
the final tracks are bad.
To take an extreme case you can copy from an image file to an
unformatted diskette with the "Track Range" set to "Data" and the disk
produced will be perfectly readable from Dos and invariably unreadable
as a master with DiskDupe (which will report an "Error 204, Record Not
Found" as soon as it reads the last data track). This disk can,
nevertheless, be compared to the image file it was created from in
DiskDupe if the "Track Range" is set to "Data".
