Joined: 06 Sep 2005 Posts: 28 Location: Minneapolis US
Following may help you...
COMPUTATIONAL or COMP (binary)
This is the equivalent of BINARY. The COMPUTATIONAL phrase is
synonymous with BINARY.
COMPUTATIONAL-1 or COMP-1 (floating-point)
Specified for internal floating-point items (single precision). COMP-1 items are 4 bytes long.
COMPUTATIONAL-2 or COMP-2 (long floating-point)
Specified for internal floating-point items (double precision). COMP-2 items
are 8 bytes long.
COMPUTATIONAL-3 or COMP-3 (internal decimal)
This is the equivalent of PACKED-DECIMAL.
COMPUTATIONAL-4 or COMP-4 (binary)
This is the equivalent of BINARY.
COMPUTATIONAL-5 or COMP-5 (native binary)
These data items are represented in storage as binary data. The data items cancontain values up to the capacity of the native binary representation (2, 4 or 8 bytes), rather than being limited to the value implied by the number of nines in the picture for the item (as is the case for USAGE BINARY data). When numeric data is moved or stored into a COMP-5 item, truncation occurs at the binary field size, rather than at the COBOL picture size limit. When a COMP-5 item is referenced, the full binary field size is used in the operation.
Specified for internal decimal items. Such an item appears in storage in
packed decimal format. There are 2 digits for each character position, except for the trailing character position, which is occupied by the low-order digit and the sign. Such an item can contain any of the digits 0 through 9, plus a sign, representing a value not exceeding 18 decimal digits.
For more details you can refer IBM COBOL Programming Guide.