Function 5Ah (90)        Create Unique File                           DOS 3.0

Creates a unique filename, then opens that file in the specified
directory.

On entry:      AH         5Ah
CX         File attribute
DS:DX      Pointer to path ending in \ (ASCIIZ string)

Returns:       DS:DX      Pointer to filename (ASCIIZ string)
AX         Error code, if CF is set

Error codes:   3          Path not found
5          Access denied

Call Function 59h for extended error code information.

Network:       Requires Create access rights

                                                                          

Function 5Ah creates a file, and opens it in compatibility mode with
Read/Write access. This function is often used to create temporary
files, but note that DOS does not automatically delete the file when
the program terminates.

Notes:         The pathname must end with a backslash character.

Reserve 13 bytes following the pathname so that DOS
can append name of the newly created file.

See also: 16h
See also: 3Ch
See also: 5Bh
See also: 59h

5Ah (90) Create Unique File >= DOS 3.0