Category: D - DOS kernel
Inp.:
AH = 3Ch
CX = file attributes (see #01378)
DS:DX -> ASCIZ filename
Return: CF clear if successful
AX = file handle
CF set on error
AX = error code (03h,04h,05h) (see #01657 at AH=59h/BX=0000h)
Notes: 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
Copied from Ralf Brown's Interrupt List