HelpPC 2.10 Quick Reference Utility Copyright 1991 David Jurgens

               INT 21,40 - Write To File or Device Using Handle

       AH = 40h
       BX = file handle
       CX = number of bytes to write, a zero value truncates/extends
            the file to the current file position
       DS:DX = pointer to write buffer

       on return:
       AX = number of bytes written if CF not set
          = error code if CF set  (see DOS ERROR CODES)

       - if AX is not equal to CX on return, a partial write occurred
       - this function can be used to truncate a file to the current
         file position by writing zero bytes

Esc or Alt-X to exit int 21,40 Home/PgUp/PgDn/End ←↑↓→
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