Примеры работы с функцией int 2Fh

--------c-2F4A10BX0000-----------------------
INT 2F - SMARTDRV v4.00+ - INSTALLATION CHECK AND HIT RATIOS
    AX = 4A10h
    BX = 0000h
    CX = EBABh (v4.1+; see Note), and CX <> 0EDCh
Return: AX = BABEh if installed
        DX:BX = cache hits
        DI:SI = cache misses
        CX = number of dirty cache elements
        BP = version in BCD (4.10 = 0410h)
        4.0  = 0400h (Windows 3.1)
        4.01 = 0401h (MS-DOS 6.0, 1992/07/30)
        4.10 = 0410h (1992/11/11)
        4.20 = 0420h
        5.0  = 0500h (MS-DOS 6.2)
Notes:  most of the SMARTDRV API, including this call, is supported by
      PC-Cache v8.0 and recent versions of the Norton Caches
    the internal name for SMARTDRV is "BAMBI", hence the magic "BABE".
    if DBLSPACE.BIN is installed but SMARTDRV has not yet been installed,
      then calls of this function with CX<>EBABh on entry cause
      DBLSPACE.BIN to display the error message
      "Cannot run SMARTDrive 4.0 with DoubleSpace" and abort the caller
      with INT 21/AX=4C00h
    Since the Novell DOS 7 - DR-DOS 7.03 NWCACHE supports a similar 
      install check at this function, but the returned registers
      contain different data, the caller must take the returned AX value
      into account to ensure proper interpretation of the returned info.
      The caller should ensure CX <> 0EDCh to avoid any interaction
      with the NWCACHE and COMMAND.COM special case of CX=0EDCh.
      Although this is an install check, NWCACHE always flushes delayed
      writes to disk, when calling this function with CX<>0EDCh or while
      /FLUSH:ON is active, but this is nothing to rely upon. The reason
      for this could be to get more accurate statistics, while SMARTDRV
      just takes a on-the-fly snapshot of the statistic vars.
    The private NWCACHE/NLCACHE install check INT2Fh/D8C0h does not flush
      to disk, and therefore can be used by callers that must ensure
      the buffers aren't flushed on this function (e.g. alternative
      command shells may need this to make their "flush before prompt"
      feature configurable).
    The NWCACHE 0EDCh special case will most probably vanish with
      future issues of NWCACHE (2.0+).
    SMARTDRV v3.x had a completely different API using IOCTL calls, which
      was also supported by the Norton Caches
BUG:    Although DS and ES registers are listed as unmodified, some
      releases of SMARTDRV seem to trash the DS register, at least the
      MS-DOS 6.2+ KEYB takes care to preserve the DS register when calling
      this function.
SeeAlso: AX=4A10h/BX=0001h,AX=4A10h/BX=0004h,AX=4A10h/BX=0005h
SeeAlso: AX=4A10h/BX=0007h,AX=4A10h/BX=1234h,AX=4A11h/BX=0000h
SeeAlso: INT 21/AX=4402h"SMARTDRV",INT 21/AX=4403h"SMARTDRV"