INT 15 - TopView - SEND MESSAGE - "WRITE" - WRITE STRING TO WINDOW
        AH = 12h
        BH = 05h
        BL = window to write to
            00h DWORD on top of stack is window handle
            01h write string to task's default window
            0Ch (DV 2.26+) default window of task owning handle on top of stack
            0Dh (DV 2.26+) default window of parent of current task
        STACK: DWORD object handle if handle passed on stack
               DWORD total length of string (high word == 0)
               DWORD address of string to display
Return: indicated actions performed
        a. non-control characters are displayed (opcodes DEh and DFh control
           whether the attributes are left or changed to the current attrib)
        b. CR/LF/BS/Tab cause the usual cursor movement
        c. ESC starts a data structure with additional commands if following
           byte is less than 20h; otherwise, it is written to the window
        STACK:  DWORD handle of new window if window stream opcode E6h
                else nothing
SeeAlso: AH=12h/BH=85h

Data Structure:
        MAGIC  DB  1Bh
        MODE   DB  ?   ; 00h, 01h, 10h, 14h-1Fh legal
        LENGTH DW  ?   ; length of remainder in bytes
        var-length fields follow, each an OPCODE followed by
             zero or more args