DOS Fn 1fH: Get Drive Parameter Block (current disk)

                                                         Compatibility: 5.0+ 
 Expects: AH    1fH
 Returns: AL    0ffh on error, else...
                0 no error and...
          DS:BX address of a Drive Parameter Block for the default drive
    Info: Returns a block of information that is useful for applications
          and utilities which perform sector-level access of disk drives
          supported by device drivers.

          This returns the pointer for the current default drive.  A more
          flexible version is DOS Fn 32H (which see for related details).

 Warning: ■ Alters DS.

Versions: ■ This known to work starting with 3.0, but has only been
            documented since 5.0.

See Also: Fn 32H (get drive parameter block)
          INT 25H/26H
          Drive Parameter Block
          Disk Drive Functions
          DOS Functions