DOS Fn 4301H: Set File Attribute

                                                         Compatibility: 2.0+ 
 Expects: AX    4301H
          CX    file attribute to assign to the file
          DS:DX address of an ASCIIZ▲ string of a filespec▲
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 Returns: AX    error code if CF is set to CY
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    Info: Sets the file attribute of a file or directory.

    DS:DX points to an ASCIIZ string in the form...
             d:\path\filename.ext◄0►
          ...which identifies the location and name of the file.  It must
          not contain wildcards▲, but it may identify a directory name.

          If CF is set on return, an error code is in AX and no action was
          taken.

   Notes: ■ To add an attribute to an existing value, use fn 4300H to
            obtain the current setting, OR the desired new attribute bit,
            then call this function.

          ■ Bits 3 and 4 of CX (volume label and directory) must be clear
            when calling this function.  If you wish to hide a directory,
            use CX=02H (not 12H as you might expect).

See Also: Fn 4300H (query file attributes)
          File Attribute
          Directory and File Functions
          DOS Functions
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