IBM 3741 Data Station Reference Manual page 35

I n this example, the accounts receivable job has two pro-
gram levels, starting in track 01, sector 01. Payroll has
three program buffers starting in track 02, sector 01,and
so on. By arranging each group of programs on a separate
track, allowance is made for adding new programs.
If, after keying these programs onto a disk, the operator
wants to load the payroll programs, the operator performs
a search on record address, keys in 02 (track) 001 (sector),
and presses REC ADV. When the first of the three payroll
programs is displayed, the operator presses FUNCT SEL
and PROG LOAD, and keys number 1. This loads the first
program into program buffer 1. By pressing R EC ADV,
selecting PROG LOAD, and keying the number 2, the next
program is loaded into program buffer 2. The third payroll
program is loaded into program buffer 3 in the same way.
Another approach would be to organize the program disk
as follows:
Address
Track Sector Record
01 0
01 Accounts receivable (header)
01 0 02
Accounts receivable program 1
01 0 03 Accounts receivable program 2
02 0 01
Payroll (header)
02 0 02 Payroll program 1
02 0 03
Payroll program 2
02 0 04 Payroll program 3
03 0 01 Accounts payable (header)
03 0
02 Accounts payable program 1
03 0 03
Accounts payable program 2
In this example, each job has a header record recorded on
the disk preceding the actual program. A header record
contains descriptive information about the programs. A
typical header record for payroll programs would be as
follows:
PAYROLL PROGRAMS-EMPLOYEE MASTER, DAILY
TIME, DEDUCTIONS.
Messages can also be included in the header program. To
find the payroll program using this approach, the operator
performs a Search on Content, keys in the word Payroll,
then presses REC ADV. This causes the data station to
search for the Payroll header record. The operator then
presses REC ADV, selects program load, and loads as many
programs as needed for that job.
Thus far, the methods of creating and storing programs
have assumed a program disk for each operator. The other
basic system approach is to include programs on the same
disks that are to contain data.
For simplicity, assume an installation has only 20 programs
for all of the jobs to be performed on the 3741. Each disk
in the installation can have a bypass data set label
established for track 1 (26 sectors), in which programs are
to be recorded. The second data set label can be established
to reserve tracks 2 through 73 for data.
Thus, an operator can insert a diskette, search for the de-
sired program, load it, and proceed to enter data on the
same diskette. The procedure would be as follows:
1. Insert diskette.
2.
Search for a program (record address or search on
content).
3. Load program(s).
4. Press the return to index key. (This returns the
read/write head to the index track, the label for the
program data set.)
5. Press the record advance key. (This increments to
the next sector on the index track, which in this case
would be the data set label for the data portion of
the disk.)
6. Select a mode. (The read/write head is positioned at
the first sector of the data portion of the disk, and
the data station is placed in the selected mode.)
I n summary, rekeying programs as they are used is inefficient
and an error prone practice. Programs should be stored on
a diskette in one of the following ways:
1.
2.
Create a separate program diskette that contains all
programs routinely used for key entry, verification,
and field totals operations.
Record the programs on the same diskette that is
used for recording and verifying data.
Program Information 29