INT 21 U - DR-DOS 5.0 - HISTORY BUFFER, SHARE, AND HILOAD CONTROL
        AH = 44h
        AL = 16h to 18h
Note:   these obsolete subfunctions (which will not be supported in future
          versions of DR-DOS) are identical to AX=4456h through 4458h
SeeAlso: AX=4456h,AX=4457h,AX=4458h

.