Int 21H, AH=3CH

2 and higher

“CREAT” - CREATE OR TRUNCATE FILE

DosOpen

      AH = 3Ch
      CX = file attributes (see #01401)
      DS:DX -> ASCIZ filename

 CF clear if successful
          AX = file handle
      CF set on error
          AX = error code (03h,04h,05h) (see #01680 at AH=59h/BX=0000h)

if a file with the given name exists, it is truncated to zero length

under the FlashTek X-32 DOS extender, the pointer is in DS:EDX

DR DOS checks the system password or explicitly supplied password at the end of the filename against the reserved field in the directory entry before allowing access

Bitfields for file attributes:

AH=16h,AH=3Dh,AH=5Ah,AH=5Bh,INT 2F/AX=1117h

Text based on Ralf Brown Interrupt List Release 61