INT 2F - HyperDisk v4.50+ - SET CACHE STATE
        AX = DF02h
        BX = 4448h ('DH')
        DL = new caching flags (see AX=DF01h)
Return: AX = 0000h if supported
            BX = number of cache buffers in use
            CX = number of cache buffers which have been modified
            DL = previous caching flags (see AX=DF01h)
Program: HyperDisk is a shareware disk cache by HyperWare (Roger Cross)
Note:   AH=DFh is the default; if it is already in use by some other program,
          HyperWare programs then scan multiplex numbers from C0h through FFh
SeeAlso: AX=DF00h,AX=DF01h

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