This is just some Unix stuff so most probably don't want to read it...
(Ok, if you use Windows and prefer cygwin mkisofs over the
commercial UltraISO software it might be still interesting)
Since it's 34C outside again i decided to stay inside and test this
"UltraISO" (works fine with WINE) method of shrinking on Metal Slug.
Ofcourse it didn't work so i tried to find out what "UltraISO" really does on
"load -> replace dummy -> save". Well it simply does a new iso while keeping
the original values for "application id", "copyright", "system id" "volume" etc.
I decided to try my luck with mkisofs and didn't really expect it to work.
To my surprise mkisofs produced an ISO i could transfer with hdl_dump
to my PS2 and play it.
I didn't try any other games yet, but chances are good that this method
works on all the games which can be shrinked with the "UltraISO" method.
Ok what i did was:
Mounting the original ISO "mount metal_slug.iso /mnt/cdrom -o loop".
Then extract all files to a folder. (You can avoid this by doing symlink
magic for everything besides the dummy file to a different folder)
Replace this APP0000.DAT with a 0 byte file "rm APP0000.DAT && touch APP0000.DAT"
Create a new ISO with mkisofs using the same ID tags as the original ISO:
mkisofs -l -copyright "PLAYMORE" -sysid "PLAYSTATION" -A "PLAYSTATION" -V "METALSLUG" -o /tmp/metal_slug_shrunk.iso .
Check with "hdl_dump cdvd_info /tmp/metal_slug_shrunk.iso":
"SLPS_256.50" "METALSLUG" 711466KB
If you don't give mkisofs the right ID args it will complain with:
/tmp/metal_slug_shrunk.iso: not a Playstation CD-ROM/DVD-ROM.
Last thing was the usual uploading to the PS2 with inject_dvd.
I don't know why UltraISO, which i used to sucessfully convert obscure
formats before, failed here. It's cool that mkisofs did the job well though.
I suggest this shrinking stuff only on images you want to transfer
with hdl_dumb or a similar tool and not for burning with growisofs etc.