Function 16h Create File with FCB

mov dx, seg FileFCB

mov ds, dx

mov dx, offset FileFCB ;ds:dx points to FCB

mov ah, 16h ;Create File with FCB

int 21h

cmp al, 0 ;zero means success

jne error_handler

Create File with FCB (16h) creates a new file having the filename specified by the file control block (FCB). If a file with the specified name already exists, MS-DOS opens it and truncates it to zero length.

This function has been superseded by Create File with Handle (Function 3Ch).

Parameter

FileFCB

Points to an FCB structure that identifies the file to create. The fcbDriveId, fcbFileName, and fcbExtent fields must specify the filename and drive. All other fields must be zero. The FCB structure has the following form:

FCB STRUC

fcbDriveID db ? ;drive no. (0=default, 1=A, etc.)

fcbFileName db '????????' ;filename

fcbExtent db '???' ;file extension

fcbCurBlockNo dw ? ;current block number

fcbRecSize dw ? ;record size

fcbFileSize db 4 dup (?) ;size of file in bytes

fcbFileDate dw ? ;date file last modified

fcbFileTime dw ? ;time file last modified

fcbReserved db 8 dup (?) ;reserved

fcbCurRecNo db ? ;current record number

fcbRandomRecNo db 4 dup (?) ;random record number

FCB ENDS

For a full description of the FCB structure, see Chapter 3, “File System.”

Return Value

If the function is successful, the AL register contains 00h. Otherwise, the AL register contains 0FFh.

Comments

This function can be used to create files on a network drive but only if the network has granted create (or similar) access to the given drive.

The EXTENDEDFCB structure can be used in place of the FCB structure to assign attributes to the file when creating it. In this case, the EXTENDEDFCB structure is used for all subsequent read, write, and close operations.