Int 2F Fn FE00  U - Norton Utilities 5.0+ Tsrs - Installation Check/statu  [U]

   AX = FE00h
   DI = 4E55h ("NU")
   SI = TSR identifier
       4346h ("CF") NCACHE-F (v5) / NCACHE (v6.0+)
       4353h ("CS") NCACHE-S (v5 only)
       4443h ("DC") DISKREET
       444Dh ("DM") DISKMON
       4653h ("FS") FILESAVE (v5) / EP (v6.0+)

Return: SI = TSR reply
       lowercase version of SI on entry (i.e. SI OR 2020h)
   AH = status
       00h installed but disabled internally
       01h installed and enabled
   AL = status
       00h NCACHE-x or DISKREET installed
       01h FILESAVE / EP / DISKMON v6 installed
       45h DISKMON v5 installed
   BX = length of *.INI file (DISKMON and FILESAVE/EP only) (see below)
   CX = segment of resident portion
       FFFFh if completely loaded high (NCACHE)
---FILESAVE/EP---
   DL = ??? (apparently always 00h)
---DISKMON---
   DX = ??? (apparently always 1AE6h [v5] / 1B86h [v6])

Note:  the value returned in CX is incorrect for NCACHE 6.00

See Also: AX=FE01h,AX=FE02h,AX=FE03h,AX=FE04h,AX=FE05h

Format of DISKMON.INI file:
Offset Size    Description
-6Ch 108 BYTEs (in memory copy only)
       list of filenames which are always protected:
         IBMBIO.COM/IBMDOS.COM, IO.SYS/MSDOS.SYS, TBIOS.SYS/TDOS.SYS,
         MIO.SYS/IO.BIN, COMMAND.COM
 00h   BYTE    ??? always 01h
 01h   BYTE    disk light (00h off, 01h on)
 02h   BYTE    disk protection (00h off, 01h on)
 03h   BYTE    protected areas
       01h system area
       02h files
       03h system area and files
       04h entire disk
 04h   BYTE    floppy access (00h not allowed, 01h allowed)
 05h 27 BYTEs  filename extension list (9 entries)
       (lowercase, blank padded or = 000000h)
 20h 240 BYTEs filename list (20 entries)
       (lowercase, name and extension blank padded, with '.')

Note:  CX:0508h -> copy in installed TSR (v5)
   CX:052Fh -> copy in installed TSR (v6)

Format of FILESAVE.INI / EP.INI file:
Offset Size    Description
 00h 26 BITs   drive list (bit set: file protection on, cleared: off):
 00h   BYTE    drives  A: - H:
 01h   BYTE    drives  I: - P:
 02h   BYTE    drives  Q: - X:
 03h   BYTE    drives  Y: - Z:
 04h   BYTE    which files to protect
       00h all files
       01h all files with extension in list
       02h all files except those with extension in list
 05h 27 BYTEs  filename extension list (9 entries, uppercase, ASCIZ)
 20h   BYTE    include files with archive bit clear (00h no, 01h yes)
 21h   WORD    number of days after which files are purged (0 = never)
 23h   WORD    max kilobytes of erased file space to hold (0 = all)

Note:  CX:03D2h -> copy in installed TSR (v5.0)
   CX:03F5h -> copy in installed TSR (v6.0)