Directory and File Functions

 39H MkDir: create a new directory      3cH create file
 3aH RmDir: remove a directory          41H delete file

 3bH ChDir: select default directory    0eH select current default disk
 47H query current default directory    19H query current default disk
 56H rename a directory

 5700H      query file time/date        5701H change file time/date
 4eH or 42H query file size             42H   change file size (pre-allocate)
 4300H      query file attribute        4301H change file attribute
                                        56H   change a file's name/move it

 5cH lock/unlock file access            Network and File-Sharing Functions
 68H commit (flush buffers to disk)
 0dH reset disk (flush buffers)         IOCTL Functions (file/device info)

 4eH 4fH search for files via ASCIIZ filename (get file info)
 11H 12H search current directory via FCB (get DirEntryRec)
 Service Groups   Data Structures   File Handles   DOS Functions