INT 10 - VIDEO - WRITE STRING (AT and later,EGA)
        AH = 13h
        AL = write mode
           bit 0: update cursor after writing
               1: string contains alternating characters and attributes
        BH = page number
        BL = attribute if string contains only characters
        CX = number of characters in string
        DH,DL = row,column at which to start writing
        ES:BP -> string to write
Notes:  recognizes CR, LF, BS, and bell
        also available PC or XT with EGA or higher
        HP 95LX only supports write mode 00h
BUG:    on the IBM VGA Adapter, any scrolling which may occur is performed on
          the active page rather than the requested page
SeeAlso: AH=0Ah