Int 15 Fn 03  - Cassette - Write Data (pc And PCjr Only)                   [B]

   AH = 03h
   CX = number of bytes to write
   ES:BX -> data buffer

Return: CF clear if successful
       ES:BX -> byte following last byte written
   CF set on error
   AH = status (see AH=02h"CASSETTE")
   CX = 0000h

See Also: AH=00h"CASSETTE",AH=02h"CASSETTE"