Int 2F Fn 0600  - DOS 3+ Assign - Installation Check                       [U]

   AX = 0600h

Return: AL = status
       00h not installed
       01h not installed, but not OK to install
       FFh installed

Notes: ASSIGN is not a TSR in DR-DOS 5.0; it is internally replaced by SUBST
     (see INT 21/AH=52h)
   undocumented prior to the release of DOS 5.0

See Also: AX=0601h,INT 21/AH=52h