I tried to use it, but there're some quirks in it that prevented me from doing so.
1. If the filenames of a disk have some non-ASCII characters it failed to extract them (and it even crashed for me occasionally). Since the filenames aren't relevant to anything I think the tool should just let the user enter the names of the exported files, instead of using the internal filenames in the disk (if this was what it was trying to do).
2. Sometimes, for unknown reasons, the HEX dump and/or the disassembly of a file on the right would be chopped off abruptly after a few lines. Maybe it was trying to display some certain characters causing this.
I ended up using
FDS Study (as infoseek took off its free web hosting service recently the site is now dead; this is an archived link) instead, which isn't very convenient (but it has enough features for it to be quite useful) as I have to use Applocale to avoid guessing on gibberish text.
BTW, if your tool is to be updated, a feature suggestion is the ability to extract a
side and to add a
side to an image. This would make say, using those FDS graphics editor disks easy, as you can put the editor on side A and the game to hack on side B (using separate images isn't very good atm as most emulators by default resets the system when you change the image). I know there're other tools to do this (and this isn't hard with hex editing) but it would be handy to have such feature.