Int 10 Fn 13  - Video - Write String (at And Later,ega)                    [V]

   AH = 13h
   AL = write mode
      bit 0: update cursor after writing
      bit 1: string contains alternating characters and attributes
      bits 2-7: reserved (0)
   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

Return: nothing

Notes: recognizes CR, LF, BS, and bell; for the ET4000 BIOS, scrolling,
     backspace, and CR only take place in the active page
   also available PC or XT with EGA or higher
   HP 95LX only supports write mode 00h
   IBM documents AL=10h,11h,20h,21h as "private" rather than "reserved"
BUG:   on the IBM VGA Adapter, any scrolling which may occur is performed on
     the active page rather than the requested page

See Also: AH=09h,AH=0Ah,AH=13h"DOS/V"