INT 2F U - MIN-MEM v2.11 - INSTALLATION CHECK
        AH = F1h
        AL <> F1h
Return: AL = F1h if installed
Note:   MIN-MEM is a shareware TSR manager by Biologic which permits up to 24
          popup TSRs to be loaded but swapped out to disk, EMS, or XMS.  One
          TSR at a time is brought back into memory at the user's request.