Creating And Storing Programs - IBM 3741 Data Station Reference Manual

An additional duplicate function called auxiliary duplica-
tion is available. For the auxiliary duplicate function, the
data to be duplicated into the current programmed duplicate
field in the record is obtained from program buffer 4. The
data in the program buffer must be in the same positions
as the field in the current record. More than one field can
be duplicated from program buffer 4 if desired. All that
is required is that, for each field to be duplicated, the
data in the program buffer be in the same positions as the
duplicate fields in the record. Program buffer 4 is loaded
with the duplicate data just as if a program were being
loaded into the buffer. The auxiliary duplicate function is
initiated by pressing NUM SH I FT and DUP. The
auxiliary duplication function is useful when data is to
be duplicated into certain records, such as header records.
Skip Fields
Fields can be programmed as skip fields. This means the
3741 will fill the field programmed as a skip field with
blanks and then go to the next field. In verify mode, skip
fields are checked for blanks. The skip field is skipped
automatically when AUTO DUP/SKIP is on. If the
AUTO DUP/SKIP switch is off, the field appears as a.
manual alpha or numeric field depending on the field
definition character. Skip field definition characters are
Sand K. The S field definition character defines a numeric-
skip field and the K field definition character defines an
alphabetic skip field. Follow the skip field definition
character used (S or K) by the appropriate continuation
character (dash or period) to complete the field.
Self-Check Fields
Self-check fields provide a method for checking the
entries in numeric fields that contain a precomputed self-
check digit. The field definition characters for self-check
fields are H, C, F, G, L, and M. The F, G, L, and M
characters are automatic field definition characters{AUTO
DUP/SKIP must be on).
The Hand C field definition characters define manual
numeric self-check fields for modulus 10 and modulus 11
respectively.
The F and G field definition characters define automatic
numeric skip self-check fields for modulus 10 and modulus
11,
respectively. I n verify mode or field correct mode,
these fields are handled as bypass fields with only the self-
check computation being performed when the self-check
feature is installed. If the self-check feature is not
installed on the 3741, the fields are handled as an auto
skip field (verified for blanks).
28
The Land M field definition characters define numeric
automatic duplicate self-check fields for modulus 10 and
11 , respectively.
For more information on self-check, see Chapter 9. Self-
Check Feature.
Creating and Storing Programs
There are two basic approaches to creating programs,
based on responsibility for creation. The first approach
follows the procedure used in many of today's card punch
installations, where each operator has the responsibility
to make up and maintain program cards. With the 3741
system, an operator can simply key and maintain programs
on the disk, rather than program cards. One disk can hold
as many as
1898
programs.
The second basic approach is that of having a supervisor,
lead operator, or system engineer create all of the programs
for every operator in the installation. Here the responsible
person keys all of the programs for the installation, then
makes copies of the master program disk for all operators.
Each operator then has a program disk, as in the first
approach; the only difference is that the program disks
were prepared centrally.
Centrally prepared program disks are maintained by chang-
ing existing programs or adding new ones to the master
program disk. Copies are then made and issued to each
operator. The effective date of the program disk can be
noted on the external label, thus indicating whether the
program disk is the latest version.
With either method of program disk preparation, the
programs must be organized in some manner so that they
can be located again. The simplest approach is to key the
programs on the disk in any desired sequence, keep track
of the addresses, and then locate the record by using search
on record address.
Another method is to arrange each group of programs on a
separate track, for example:
Address
Track Sector
Programs
01 0 01 Accounts receivable
01 0
02 Accounts receivable
02 0 01 Payroll
02 0 02
Payroll
02 0 03 Payroll
03 0 01 Accounts payable
03 0 02
Accounts payable