Usage - Control Data Corporation 3300 Reference Manual

3.5.15
USAGE
3-40
The USAGE clause specifies the format of a data item
in
storage.
USAGE IS
DISPLAY
{
COMPUTATIONAL}
COMP
{
COMPUTATIONAL-1 }
COMP-1
{
COMPUT ATIONAL-2 }
,COMP-2
INDEX
- - -
The USAGE clause can be written at any level; at a group level, it applies to
each elementary item in the group. The USAGE clause of an elementary item
cannot contradict the USAGE clause of a group to which the item belongs.
H USAGE is not specified for an elementary item, or for any group
to which
the item belongs, usage is assumed to be DISPLAY. DISPLA Y indicates
that the data is standard data format. Standard data format uses the decimal
system to represent numbers (regardless of the radix used by the computer),
and the remaining characters in the COBOL character set
to
describe non-
numeric data items.
A COMPUTATIONAL item contains a value to be used in computations; it
must be numeric. The PICTURE string of a COMPUTATIONAL item without
an integer suffix can contain only 9 S V and one or more pI s. H a group
item is described as COMPUTATIONAL, the elementary items in the group
are COMPUTATIONAL; however, the group item, itself, is not COMPUTA-
TIONAL since a group cannot be used in computations. A COMPUTATIONAL
item is stored in standard data format and its sign is stored over the low-
order numeric digit. Its size must not exceed
18
numeric digits.
COMPUTA TIONAL-1 describes an elementary item in fixed point binary
format. Such an item occupies one computer word (24 bits) and its value
may not exceed 223_1. A fixed point binary number consists of a Sign bit
and coefficient as shown below:
2322
00
II
coefficient
+
sign bit
60229400