iTS 1.0+)

SCREEN COBOL Source Program

Compaq NonStop™ Pathway/iTS SCREEN COBOL Reference Manual—426750-001

2-29

Data Representation

In the Working-Storage Section and Linkage Section, data items are stored in a certain

number of bytes; each byte is an 8-bit unit of storage. Bytes are grouped in pairs to form

words.

Data items whose usage (as defined by a USAGE clause) is DISPLAY occupy one byte

per character. Table 2-10

indicates the storage occupied by data items whose usage is

COMPUTATIONAL.

In the Screen Section, items do not have individual storage assigned; storage of these

items is of no consequence to SCREEN COBOL programming.

Standard Alignment

The standard rules for positioning data within an elementary item depend on the

category of the receiving item. The rules are as follows:

•

If the receiving data item is described as numeric, the sending data is aligned either

by decimal point with zero fill on either end of the value or by truncation on the low

end, as required. Truncation on the high end is not permitted, and if required, causes

suspension of the program. When no decimal point is specified, the receiving data

item is treated as if it had an assumed decimal point immediately following the

rightmost character.

•

If the receiving data item is described as alphanumeric or alphabetic, the sending

data is aligned at the leftmost character position in the data item with space fill or

truncation to the right as required.

Optional Alignment

Standard data representation and alignment rules are not always appropriate, so

provisions exist to override them. The JUSTIFIED clause can be used in the data

description to right justify data within a data item.

Sometimes a server requires that data items in messages be aligned on word boundaries.

Data items aligned on word boundaries are said to be synchronized. Synchronization

typically is achieved by organizing and describing data so that item boundaries coincide

with word boundaries. This task can be eliminated by using the SYNCHRONIZED

clause to force alignment of data items to their natural boundaries.

Table 2-10. Storage Occupied by COMPUTATIONAL Data Items

PICTURE Size in Digits Storage Occupied

1 through 4 2 bytes

5 through 9 4 bytes

10 through 18 8 bytes