such as ä and ê. DOS\3: International mode, for FFS (FFS-INTL). This was the most commonly used FFS mode. (All higher dostypes have international mode always enabled.) DOS\4: "Directory Cache" (OFS-DC) mode enabled to primitive cache by creating dedicated directory lists instead of having to pick up the linked directory/file entries that lie scattered over the disk. A certain (small) amount of disk space to store the directory data is allocated. The DirCache option improved directory reading speed drastically but creating, deleting and renaming files became slower. It did not increase the speed of reading individual files. It became a popular choice on Amiga hard drives, but according to Olaf Barthel, author of FFS2, the use of dircache modes was probably better for floppy disks than it was for hard drives, where it would cause an overall degradation in performance compared to lack of dircache. Despite this it was rarely used on floppies, particularly because of the cache eating precious space, and because of the limited space preventing a large number of files to cache in the first place. The dircache mode lacks a "garbage collection" mechanism, which means that partly filled cache blocks are never consolidated and will keep taking up space. DOS\5: Directory caching with FFS (FFS-DC). Both dircache modes were not backwards compatible with earlier versions of FFS. Version 40.1 was the last version of FFS released by Commodore, and came with AmigaOS 3.1, both on the OS disks and in the ROM. After this, several Unofficial patches appeared which allowed its use on drives after the first 2 GB of a hard disk using a 64-bit addressing system called TrackDisk64 or TD64 (although the 2 GB limit on file size and the 127 GB limit on partition sizes remained, as it was a limitation of AmigaOS dos.library and all then-current Amiga software) and carried the version number of v44. The version of FFS that came with AmigaOS 3.5 and 3.9 was v45 and differed in that it used a different 64-bit addressing system, New Style Device or NSD. More recently (from 2003), MorphOS and AmigaOS 4 have introduced support for a slightly updated "FFS2", by Olaf Barthel (FFS v46, v50 respectively). This is compatible with the older FFS. It is PowerPC native, and introduced two more dostypes (which are not capable of being read by the older FFS): DOS\6: "Long Filename" (OFS-LNFS). This allowed files to