INT 2F U - NORTON UTILITIES 5.0+ TSRs - INSTALLATION CHECK/STATUS REPORT
        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
SeeAlso: 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)