Mainframe storage of numbers question

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Mainframe storage of numbers question

Postby pintu1228 » Wed Mar 22, 2017 9:08 am

Hi everyone,

I just wanted to know what the value -8453.234 looks like in mainframe storage if stored in packed decimal and also if stored in zone decimal.

Can anyone help me understand this??

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Re: Mainframe storage of numbers question


Re: Mainframe storage of numbers question

Postby steve-myers » Wed Mar 22, 2017 10:09 am

In hexadecimal representation
Packed - 8453234D
Zoned - F8F4F5F3F2F3D4

There are other, equally valid representations.

The last byte reflects the "preferred" sign for a negative number.

You can find more information through this link.
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Re: Mainframe storage of numbers question

Postby Robert Sample » Wed Mar 22, 2017 2:31 pm

One thing to note is that the decimal point itself is NOT stored in either zoned decimal nor packed decimal -- it is an implied decimal point only. If you need the decimal point stored, you use the "numeric edited" form of the PICTURE clause in COBOL.
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Re: Mainframe storage of numbers question

Postby enrico-sorichetti » Wed Mar 22, 2017 2:52 pm

the manual
z/Architecture Principles of Operation

available here ( You might need to register to download ) ... c500428f9a

will tell all You might want to know about internal number representation
When I tell somebody to RTFM or STFW I usually have the page open in another tab/window of my browser,
so that I am sure that the information requested can be reached with a very small effort
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