A sequential (SEQ) device specification, entered in positions 36 through 42 in the file description specification, indicates that the input or output is associated with a sequentially-organized file. Refer to Figure 189. The actual device to be associated with the file while running the program can be specified by a IBM i override command or by the file description that is pointed to by the file name. If SEQ is specified in a program, no device-dependent functions such as space/skip, or CHAIN can be specified.
The following figure shows the operation codes allowed for a SEQ file.
| File Description Specifications Positions | Calculation Specifications Positions | |
|---|---|---|
| 17 | 18 | 26-35 |
| I | P/S | CLOSE, FEOD |
| I | F | READ, OPEN, CLOSE, FEOD |
| O | WRITE, OPEN, CLOSE, FEOD | |