What is the difference between zoned decimal and packed decimal?

What is the difference between zoned decimal and packed decimal?

Zone decimal uses an entire byte for each digit. This means you can just print a number as if it was text (each ‘character’ stores a digit 0-9) but since there are only 10 digits and a byte can hold 256 different values this is a bit wasteful. Packed decimal uses the fact that 4bits can store 16different values.

How do you convert a decimal to a zoned decimal?

This can be accomplished using SORT. p,m,PD,TO=ZD converts the PD values to ZD values. By default, a 4-byte BI value produces a 7-byte ZD value, but LENGTH=6 override the default length to produce a 6-byte ZD value.

How do you declare a packed decimal in COBOL?

For example, on the mainframe the value 12,345 would be five (5) bytes in length (i.e. x’F1F2F3F4F5′). If the same information is stored in a packed-decimal (i.e. USAGE IS COMPUTATIONAL-3 or abbreviated as COMP-3) the field would be three (3) bytes in length (i.e. x’12345C’).


Digit Digit
1 2
0001 0010
1 2

What is packed decimal in SAP?

A packed number consists of the length multiplied by 2 minus 1 digits and can have a maximum of 14 decimal places. Packed numbers are used to implement fixed point numbers. The decimal places in a packed number are an attribute of its data type and are fixed for this type.

What is zoned decimal in sort?

A zoned decimal representation stores a decimal digit in the low order nibble of each byte. For all but the byte containing the sign, the high-order nibble is the numeric zone nibble (F on EBCDIC and 3 on ASCII). The sign can be merged into a byte with a digit, or it can be separate, depending on the representation.

What is ZD format?

The ZD format fills in zeros to the left of the data value. Like standard format, zoned decimal digits are represented as EBCDIC characters. Each digit requires one byte of storage space. The rightmost byte represents both the least significant digit and the sign of the number.

What is meant by packed decimal?

Packed-decimal format means that each byte of storage (except for the low order byte) can contain two decimal numbers. The low-order byte contains one digit in the leftmost portion and the sign (positive or negative) in the rightmost portion.

How do I view packed decimal data?

You can use DFSORT to convert the packed decimal numbers into readable formats. There are 27 pre-defined DFSORT editing masks are available for commonly used numeric editing patterns, encompassing many of the numeric notations used throughout the world.

What is ZD in mainframe?

ZD is signed zoned decimal in the form X’FdFd… sd’ where d is a digit (0-9) and s is the sign (usually C or F for plus and D for minus). ZD collates as signed numbers (e.g. -123 before +123).

What is packed decimal in COBOL?

How do you write ZD?

The ZD format fills in zeros to the left of the data value. Like standard format, zoned decimal digits are represented as EBCDIC characters. Each digit requires one byte of storage space.

  1. ‘F0’x=0, ‘F1’x=1, and so on.
  2. ‘C0’x=+0, ‘C1’x=+1, and so on.
  3. ‘D0’x=-0, ‘D1’x=-1, and so on.

How do I get comp 3 values?

1. In case the COMP-3 Data, that you want to see is the data in a Mainframe File, and you would like to see the contents on TSO/ISPF, you can turn the HEX ON on the Command Line. In the below file, the last 2 Bytes are COMP-3 Data. You read the Hexa-decimal value in a top-down fashion.

How do you convert packed decimals to numbers?

This document describes how packed decimal values (Computational-3) can be converted to numeric values via File Master using COBOL copybooks. The only method to get this done is to use a File Master Reformat data set, aka. REFFILE. (“11 REFORMAT Convert file from one record layout to another”).

What is zoned decimal in COBOL?

A zoned decimal is a USAGE DISPLAY item where every digit is represented using one byte character, the corresponding ASCII or EBCDIC character is used for each digit.

What is the difference between Comp and Comp-3?

COMP usage stores the data in half word or in full word, depending on the size of the data. COMP3 usage stores 1 digit in half byte (i.e. 4 bits) and a separate 1 bit is reserved for the sign, which is stored at the right side of the data.

What does packed decimal look like?

Packed Decimal Data

A packed decimal representation stores decimal digits in each “nibble” of a byte. Each byte has two nibbles, and each nibble is indicated by a hexadecimal digit. For example, the value 15 is stored in two nibbles, using the hexadecimal digits 1 and 5.

What is zoned decimal in mainframe?

In zoned-decimal format, each digit in a decimal number includes a zone portion; however, only the low-order zone portion serves as the sign. Figure 1 shows what the number 21544 looks like in zoned-decimal format. You can specify an alternative sign format for zoned-decimal format.

Which is faster COMP or COMP-3?

Comp-3 = Packed-Decimal is faster, because the z/Architecture, and also previous architectureres beginning with S/360, has built in instructions to directly manipulate Packed-Decimal data, e.g AP (Add packed).

How do you read BCD?

Binary Coded Decimal Representation of a Decimal Number
In the BCD number system, the binary weight of each digit increases by a factor of 2 as shown. Then the first digit has a weight of 1 ( 20 ), the second digit has a weight of 2 ( 21 ), the third a weight of 4 ( 22 ), the fourth a weight of 8 ( 23 ).

Why do we use comp-3?

COMP-3 enables the computer to store two digits in each storage position, except for the rightmost position, which holds the sign. Suppose if you move 1234567 into a field defined 9(7). In DISPLAY mode, which is default, this field will use 7 storage positions.

What is the difference between COMP-1 and COMP-2?

COMP-1 refers to short (single-precision) floating-point format, and COMP-2 refers to long (double-precision) floating-point format, which occupy 4 and 8 bytes of storage, respectively. The leftmost bit contains the sign; the next seven bits contain the exponent; the remaining 3 or 7 bytes contain the mantissa.

What is Zone in BCD code?

The BCD code is the adaptation of the punched card code to a six-bit binary code by encoding the digit rows (nine rows, plus unpunched) into the low four bits, and the zone rows (three rows, plus unpunched) into the high two bits.

Why is BCD used?

The goal of BCD is to make it simpler to convert human numbers into values that a machine can understand. BCD can automate some tasks and systems for humans and make these processes operate with greater efficiency.

What is the difference between Comp 1 Comp 2 and Comp-3?

COMP-2 is more precision than COMP-1. Interview Question : Why COMP-1, COMP-2 don t have PIC clause? PIC creates relation between data name and data type. Whereas here data is numeric and length is predefined as one word floating for COMP-1 and double word floating for COMP-3.

Which is better comp or COMP3?

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