IBM Mainframe Forum

by **dick scherrer** » Thu Apr 01, 2010 11:45 pm

Hello,

I don't know what you're doing that gave X'00000000D25C5C5C...' instead.

The 5Cs are literals in the code, not the result of the PACK.

Rather than invest much time on why the incorrect PACK coding gave the result it did, i'd suggest concentrating on if the correct code produces the correct result. Does it?

by **helen2000** » Fri Apr 02, 2010 12:45 am

I'm sorry, I'm really interested in mainframe assembler. I think it's very useful for undertanding the detail about compiler info as you
said. but so far I still didn't get the permission for code assembler programming in mainframe env. in my organization. no way, I have to use pc/370 mainfrme assembler software intead . maybe there are some difference between pc/370 and mainframe assembler.
but as the Author's said, no difference between the 2 version because it imitate the MVS ASSEMBLER. anyway, thanks you all help.

Helen.

by **Frank Yaeger** » Fri Apr 02, 2010 1:41 am

Helen,

It took some doing, but I got as close as I could to the "equivalent" of your program to run on the ASMA90 Assembler (but it's not an exact equivalent). The output records looked like this in hex:

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Record 1 (before)
F1F0F6F3F95C5C5C14312D5C5C5C0D25

Record 2 (after)
00000041D25C5C5C14312D5C5C5C0D25

So I can only guess that there's something different about the Assembler you're using, or the OREC record is being overlayed at some point.

I do applaud you for your curiosity about what's going on. Good programmers should be curious. I just don't know how to help you more at this point since I can't duplicate what you're seeing.

I personally find TSO TEST a great way to debug Assembler programs (instruction by instruction) but I don't know if you know how to use it or have it available. If you do have something that lets you step through your program instruction by instruction, I'd suggest using that to see what's happening where in your program.

by **helen2000** » Fri Apr 02, 2010 2:44 am

Hi Mr.Frank
I'm very appreciated you give me a encouragement and tell me very valuable info. I have more confidence to do some research under your help.
I will look for a way to step trace my code. I will let you know if I got any valuable info.
thank you again.
have a nice long weekend!
Helen

by **Frank Yaeger** » Fri Apr 02, 2010 3:47 am

If you can't step trace your code, another trick (though not as good) would be to force an S0C1 ABEND at the point where you want to look to see what's in storage.
For this to work, you need to add

//SYSUDUMP DD SYSOUT=*

to your job so you get the dump.

For example, you could change your code to have:

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...
PACK ONN,OZZ
LA 3,OREC
DC H'0'
...

That will give you an S0C1 dump just after the PACK with reg 3 pointing to your OREC area so you can see what's in it (assuming you know how to look at a dump).

Hopefully, you have a MSGCLASS you can set that will let you look at your JES output online so you don't have to print it out.

by **helen2000** » Thu Apr 08, 2010 3:03 am

during a couple of days' working hard, finally I find the answer:
1: at first, we need to understand 2 develop enviorment: pc/370 MVS assmbler imitator in DOS,
MVS Z/os assmbler in mainframe.
2: my code is from pc/370 in Dos;

3: for all display character, ASCII code in DOS, and EBCDIC code in MVS Mainframe.

4: in my code, the following statement is for convert report.txt from EBCDIC to ASCII

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OI REPORT+10,X'08' PC/370 ONLY - Convert all
* output from EBCDIC to ASCII

5: so, when I remove the above statement, we will get the correct answer. x'14312d' will
be change to x'41d2'.

6: one more question, why do I got the following incorrect output in last test I talked about several days ago?

I will trace my code:
at first take a look main patest.prn list program as following:

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000074 39 *+++++++ OPEN TEACHERS
000074 4120D118 0128 40 LA 2,TEACHERS
000078 0A01 41 SVC 1
00007A 42 *+++++++ OPEN REPORT
00007A 4120D17C 018C 43 LA 2,REPORT
00007E 0A01 290 44 SVC 1
000080 D201D1EDD1DD 01FD 01ED 45 ATEND MVC OCRLF,WCRLF
000086 46 *+++++++ PUT REPORT,OREC
000086 4120D17C 018C 47 LA 2,REPORT
00008A 4110D1DF 01EF 48 LA 1,OREC
00008E 0A06 49 SVC 6
000090 F242D1DFD1E7 01EF 01F7 50 PACK ONN,OZZ
000096 51 *+++++++ PUT REPORT,OREC
â™€ PATEST PAGE 2
PC/370 CROSS ASSEMBLER OPTIONS=LXACE
LOC ADR1 ADR2 LINE LABEL OP OPERANDS
000096 4120D17C 018C 52 LA 2,REPORT
00009A 4110D1DF 01EF 53 LA 1,OREC
00009E 0A06 54 SVC 6
0000A0 55
0000A0 56 *
0000A0 57 * EOJ processing
0000A0 58 *
0000A0 59 *+++++++ CLOSE TEACHERS
0000A0 4120D118 0128 60 LA 2,TEACHERS
0000A4 0A02 61 SVC 2
0000A6 62 *+++++++ CLOSE REPORT
..........
.........

0001ED 0D25 109 WCRLF DC X'0D25' PC/
370 ONLY - EBCDIC CR/LF
0001EF 110 * Output (line) definition
0001EF 111 *
0001EF 112 OREC DS 0CL16
0001EF F1F0F6F3F9 113 ONN DC CL5'10639'
0001F4 5C5C5C 114 DC CL3'***'
0001F7 14312D 115 OZZ DC PL3'-14312'
0001FA 5C5C5C 116 DC CL3'***'
0001FD 117 OCRLF DS CL2 PC/
370 only - CR/LF
000000 118 END BEGIN

**********************

SO, before execute the following SVC 6,
OZZ still is x'14312d' in memory

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00008E 0A06 49 SVC 6

but, after execute SVC 6,
OZZ will be changed to x'00002D'.
I think this is the key of the problem. could you tell me what does it
means this struction: SVC 6 ; what does it do exactly? I can't check it in internet.

thank you, all,

hellen

by **Frank Yaeger** » Thu Apr 08, 2010 4:03 am

For z/OS Assembler, SVC 6 is LINK. It links to the module you specify.

But for the Assembler you're using, it appears SVC 6 is for PUT. I based that on the information I found here:

http://www.cs.uni.edu/~okane/041/ibm390.html

I doubt that anyone on this Forum knows what code that SVC executes or why it does what it does in your program.

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