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tommy123 · Beginner Joined: 04 May 2005 Posts: 21 Topics: 11

Hai,

I am new to Mainframes & i am presently undergoing training.I am trying to know what hexadecimal values are.I create a member and enter the value 32 and to see the value i do 3.4 ,do hex on i get the display

000001 32
FF4444444444444444444444444444444444444444444444444444444444444444444444
320000000000000000000000000000000000000000000000000000000000000000000000

If i change the value to 15 in the member & i put on HEX on i still get the same display

000001 18
FF4444444444444444444444444444444444444444444444444444444444444444444444
180000000000000000000000000000000000000000000000000000000000000000000000

Then what is the difference in the hexadecimal values of 32 & 18 as the hexadecima values are 20 & 0F respectively.Can anyone please tell me if i am wrong.Why is there extra F & all 44444444444444 what does it mean ?How can i see values in 3.4 option

s_shivaraj · Posted: Wed May 04, 2005 1:43 am Post subject:

tommy123,

U need to read the Hex values vertically, i,e each character is displayed by its corresponding values in the next 2 lines..

kolusu · Posted: Wed May 04, 2005 5:14 am Post subject:

tommy123,

Mainframes use the EBCDIC code page 1140. Check this link which will gives you the list of for single-byte EBCDIC code page 1140 with hex reprenstation.

http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/IGY3LR10/APPENDIX1.3.1?SHELF=&DT=20020920180651&CASE=

Hope this helps...

Cheers

Kolusu
_________________
Kolusu
www.linkedin.com/in/kolusu

tommy123 · Beginner Joined: 04 May 2005 Posts: 21 Topics: 11

Hai Sivaraj & Kolusu,

Thanks for u replies & i am very clear with the concept of Hexadecimal values now.My understanding is that Mainframes uses EBCDIC values & follows the table code page 1140.I am seeing some values like the ones below when i open a dataset with 3.4 option .What are these values & for these values(symbols) there is no matching at all in the table .I presume these values to be ASCII values if i am correct.How are these ASCII values different from EBCDIC values & i have seen them in many load modules and why do we use them.Do all these ASCII values have their equivalent EBCDIC ,decimal & Hexadecimal values respectively.If any help is there ,i will greatly appreciate as i will be clear with the basic concepts of storage.

kolusu · Posted: Thu May 05, 2005 8:04 am Post subject:

tommy123 · Beginner Joined: 04 May 2005 Posts: 21 Topics: 11

Thanks Kolusu,

Now i have a fair knowledge of internal representation of numbers.Can u please highlight on the difference betweeen EBCDIC & ASCII values in what are they different ? How do ASCII values look like & why do we use ?

kolusu · Posted: Thu May 05, 2005 1:29 pm Post subject:

tommy123,

Mainframes use the EBCDIC code set, while PCs use the ASCII codeset. ASCII sequence has the numbers before the letters/alphabets whereas EBCDIC code set has letters/alphabets first , followed by numbers.

Check this link for

EBCDIC and ASCII collating sequences

Hope this helps...

Cheers

kolusu
_________________
Kolusu
www.linkedin.com/in/kolusu

tommy123 · Beginner Joined: 04 May 2005 Posts: 21 Topics: 11

Thanks Kolusu,

Now i am very clear and have good understanding with internal data represntation of numbers ,Hex values,EBCDIC & ASCII values too.
This group is very much useful to beginers like me to learn a lot and by sharing a lot of info among new members.

I am opening a dataset in 3.4 option in edit / view mode and i get the message on the top of the data starting as :

-CAUTION- Data contains invalid (non-display) characters. Use command
===> FIND P'.' to position cursor to these

I issue this command & press F5 fucntion key & my cursor goes to all blanks and forwards ahead.Now when i open the same member in browse mode,wherever spaces were there visible in edit/view mode they all are now filled up with ....... I issue F5 again & my cursor goes to all ... one by one.Why is there a difference in display when i open in EDIT/VIEW mode to BROWSE mode.Can anyone tell me what is the use of the command
FIND P'.' ?

Dibakar · Posted: Fri May 06, 2005 1:15 am Post subject:

Those are not blanks. FIND P'.' will take you to invalid characters, I beleive it is same as non displayable characters.

The editor shows non displayable characters as blanks and the browser shows them as dots. Why? I am also curious to know that.

I don't have the quick manual link so I am doing a cut paste from mainframe help on "Edit Primary Commands/Find commands/Find/Specifying Char.../Picture...."

[code:1:ca7c293b2c]
The special characters that can be used in a picture string are:

= any character . invalid characters
@ alphabetic characters - non-numeric characters
# numeric characters < lower case alphabetics
$ special characters > upper case alphabetics

tommy123 · Beginner Joined: 04 May 2005 Posts: 21 Topics: 11

Thanks Dibakar,

I have tried out all the options in my shop & i founf them working successfully.Now i have a clear understanding of displayable & non displayable characters.

tommy123

Dibakar · Posted: Sat May 07, 2005 1:21 am Post subject:

You are welcome. Hope you enjoyed.

In case you are still interested, try to search for comma (,) using find command.

semigeezer · Posted: Sat May 07, 2005 8:51 am Post subject:

The reason that the editor looks like blanks and browse uses a character (you can change the character in browse with the DISPlay command) is that the editor is actually putting an attribute byte to the screen so that when you type in a line, the non-displayble character is not changed. This is to prevent you from accidentally modifying characters you can't see. Attribute bytes look like blanks.