IBM 5280 Programmer's Manual page 32

The following text explains some of the statements in figure 2.3; later sections
in this chapter give detailed rules for coding each field.
II
The Sequence Number field (columns 1-5). The number in this field appears
in the source listing under the SEQ.# column, as shown in figure 2.4.
fJ
The Name Type field (column 17). For record description statements, this
field contains an R. For field description statements, this field contains a
blank.
II
The Record Name field (columns 19-26 for record description statements) or
the Field Name field (columns 19-24 for field description statements). These
names (EMPRECD, ACREC, EMPNO, etc.) will appear as the 01 and 02
level data items in the COBOL program, as shown in figure 2.4.
II
The Length field (columns 30-34 for field description statements only.) This
field specifies the length of the field on the screen, and the size of the 02 level
data-item in the COBOL program, as also shown in figure 2.4.
II
The Data Type field (column 35 for field description statements only). This
field defines the data type and keyboard positioning, in this example A for
alphabetic shift,
D
for digits only, and
X
for alphabetic only.
m
The Decimal Positions field (column 37 for field description statements only).
This field determines whether the corresponding data-item in the COBOL
program will be compiled as alphanumeric or numeric. If blank, the data-item
will be alphanumeric; if any number between 0 and 9 (indicating a decimal
position), the data-item will be numeric.
In the example, the Decimal Positions fields all contained blanks. As shown in
figure 2.4, this created alphanumeric (X) data-items for all the fields.
D
The Usage field (column 38). This field defines whether or not the operator
can enter data in the field. If it is
B
(for both input and output) the operator
can enter data into the field, and the program can write data from the field to
the screen. If it is 0 (for output only), the program can only write data to the
screen using literal statements as will be shown later.
aNotel: You can access in your COBOL program only those fields defined
with usage B. As shown in figures 2.3 and 2.4, only B fields are compiled as
data-items.
aNote 2: Wand
I fields (shown on the coding form) aren't valid fields for
COBOL programs.
iii
The Location field (columns 39-44 for field description statements only). This
field specifies the line and column number where the field is to appear on the
screen.
The physical line number on the screen where the field will appear depends on
(1) the value you code in columns 39-41 and (2) the value you code in the
STARTING AT LINE clause in the associated WRITE statement in your
program. See the section "Location Field" for the rules on how these two
values affect the placement of fields on the screen.
The value you code in columns 42-44 determine the horizontal placement of
the field.
II
The Editing field (columns 45-80). You write the keywords that control the
editing, field attributes, and keyboard conditioning in this field. Some of these
keywords used in this example will be explained in the following text. Refer to
figure 2.5 while reading the text.
Chapter 2. Transaction I/O - Screen Definition 2- 5