DOS Fn 3bH: Set DOS Default Directory -- CHDIR

                                                         Compatibility: 2.0+ 
 Expects: AH    3bH
          DS:DX address of an ASCIIZ string of a directory name
 Returns: AX    error code if CF is set to CY
    Info: Selects a default directory for a drive.

          DS:DX points to an ASCIIZ string in the form...
          ...which identifies the directory to become the default.  If the
          d: portion is missing, the \path\dirname is assumed to be on the
          current default drive; see Fn 0EH (set default drive).

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

   Notes: ■ This selects the default directory for the specified or current
            drive.  it DOES NOT select a default drive.
          ■ If drive and/or leading path are omitted, defaults are assumed.
          ■ The maximum length of the ASCIIZ string is 64 bytes.

See Also: Directory and File Functions
          DOS Functions