is a television picture format used in the United States and Japan.
You will probably have to reformat that drive, using the PC, to enable it to work correctly once more.
I've got an external HDD formatted in NTSC that worked fine on my Macbook (i've got NTSC-3G installed) and on windows laptops, until I accidentally unplugged it without ejecting on my mac. Now, the drive is read-only on macs and readable an writable on a PC. I tried repairing permissions in disk utility but all the buttons (repair, repair permissions, verify..) are disabled, I can't get my macbook to write on that drive anymore! Has someone got an idea to fix this problem? I'm lost. Thank's!