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SrilathaB · Beginner Joined: 29 Dec 2004 Posts: 2 Topics: 1

Hi

I have written a small assembler program to add two numbers and subtract '1' from the total.
When I assembled the program I got zero return code. But when I am runnning the program
I am getting RC '4056'

Here is the code.

nevilh · Beginner Joined: 11 Aug 2004 Posts: 115 Topics: 0

Register 15 has not been cleared

Dibakar · Posted: Fri Jun 10, 2005 2:01 am Post subject:

But what is 4056, I am also getting it if I don't clear R15.

nevilh · Beginner Joined: 11 Aug 2004 Posts: 115 Topics: 0

4056 is x'fd8' which in this case would be the low order part of the load address of the program tha was invoked

Mervyn · Posted: Fri Jun 10, 2005 3:53 am Post subject:

When I run it, the low order part is x'FC8', which is decimal 4040. I still get return code 4056 though. Where does the extra 16 come from?
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Mervyn · Posted: Fri Jun 10, 2005 4:25 am Post subject:

OK, here's an update.

I put in an ABEND macro to show the register contents, and got this result:

nevilh · Beginner Joined: 11 Aug 2004 Posts: 115 Topics: 0

I used the DC f'0' to get the abend and low order bytes of entry address and return code always correspond if I use standard assembler linkage conventions.
If I use the pgm as coded above I get a discrepancy of 8 bytes between the entry address and the return code

Mervyn · Posted: Fri Jun 10, 2005 6:30 am Post subject:

I guess that means we're BOTH confused!

The principle's perfectly correct, though!

Cheers,
Merv
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Dibakar · Posted: Fri Jun 10, 2005 10:41 pm Post subject:

One more question, why does everybodies program gets loaded at the same address?

Dibakar · Posted: Fri Jun 10, 2005 11:23 pm Post subject:

I did a DC F'0' with this code and this is what I got -

SrilathaB · Beginner Joined: 29 Dec 2004 Posts: 2 Topics: 1

Thanks Mervyn!

I also used ABEND with DC A(0), I too got same results .
The Reg R15 is contains F: 00007FD8.

But when I am expediting I am getting R15 value as
R15 ==> 000070E0

Plz can anybody let me know why different value is coming while expediting.

Thanks,
Srilatha.
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srilatha Bandi

nevilh · Beginner Joined: 11 Aug 2004 Posts: 115 Topics: 0

Dibakar;The reason programs get lo loaded at more or less the same point (24 bit residency) is that at address space creation time the system will copy the PSA into the first 4k and after this storage is reserved for system getmains (16k I think) and then the system will put what it requires in and then your program will be loaded. There is a good description of this in one of the Initialization and Tuning manuals

Dibakar · Posted: Sat Jun 11, 2005 5:12 am Post subject:

Thanks nevilh.