Int 13 Fn 43  - Ibm/ms Int 13 Extensions - Extended Write                  [d]

   AH = 43h
   AL = write flags
      ---v1.0,2.0---
      bit 0: verify write
      bits 7-1 reserved (0)
      ---v2.1---
      00h,01h write without verify
      02h write with verify
   DL = drive number
   DS:SI -> disk address packet (see #0204)

Return: CF clear if successful
       AH = 00h
   CF set on error
       AH = error code (see #0166)
       disk address packet's block count field set to number of blocks
         successfully transferred

Note:  the BIOS returns CF set/AH=01h (invalid function) if verify is
     requested but not supported

See Also: AH=03h,AH=41h"INT 13 Ext",AH=42h"INT 13 Ext",AH=44h