Sequential Work Station I/O - IBM 5280 Programmer's Manual

SEQUENTIAL Work Station I/O
Here are the rules for input/output between a work station and a COBOL
program:
1. The entries in the FILE-CONTROL paragraph are:
SELECT file-name ASSIGN TO WORKSTATION
[n]
ORGANIZATION IS SEQUENTIAL
[FILE STATUS IS data-name-3]
[ACCESS MODE IS SEQUENTIAL]
WORKSTATION indicates this is a work station for a sequential file.
n
is an integer that specifies one of the three sizes of work station screens
as follows:
480 for the 480-character screen.
960 for the 960-character screen.
1920 for 1920-character screen.
If you don't specify n, a screen size of 1920 characters is assumed.
2. The maximum record size that can be written is 78 bytes. If the record
defined in your program is greater than 78 bytes, the excess characters will
be truncated. If the record is less than 78 bytes, the right-most bytes will be
padded with blanks.
3. Specify OUTPUT mode in the OPEN statement for the file defined for the
work station.
4. If a sequential file and a transaction file are both assigned to the work
station, only one of them can be open at a time. However, multiple
sequential files assigned to the work station can be open simultaneously.
5. ACCEPT and DISPLAY statements can be issued while a SEQUENTIAL
I/O file for the work station is opened.
6. The ADVANCING mnemonic-name phrase is not supported for the
WRITE statement.
7. The AT END imperative phrase will be ignored. It will not be executed
because an AT END condition cannot occur on a work station.
8. If the screen is clear, the first record written to the screen will appear in
line 3. Otherwise, the first record will appear after the last line already on
the screen.
9. When the last line of the screen has been used, the next record will be
wri tten to line 3.
6- 4 IBM 5280 COBOL Programmer's Guide