Re: program check in an assembler program

"Lolobg"  wrote
> I'm currently starting with assembler language
>
> While executing one of my assembler program that read a pds member I've
> got a ABEND SB00 . Message : A program check occured during EXCP
> processing of an I/O request.
>
> The same program works when running under my debugger (ASG smartest).
> I've made many tests changing AMODE/RMODE but I cannot find out what's
> going wrong with it?
>
> This program is reentrant an compiled with AMODE=24 RMODE=24
>
> Could someone explain in simple terms what a program check is ?
> Does anyone have an idea in which way I should investigate?

"Program Check" means that there is something wrong with your
channel program.

The error has been detected by the subchannel and there may be
several reasons for the program check. First of all I think you should
consult the subchannel status word (SCSW) preferably by using
some of the diagnostic tools available on your system.

But I am kind of surprised: If you are just "starting up with asssembler
language" then I/O programming is not what I would expect you to try
for at least many months to come. There should be plenty of data
processing macros available for whatever you may want to do.

In fact I believe that most security systems prevent user programs from
executing their own channel programs, such progrfams must call on
operating system services to have their I/O tasks performed and the
channel programs used will be part of the operating system.

Coding your own channel programs is definitely not recommended
until you have obtained a high level of expertice, maybe not even then.

regards Sven

LH      R0,=F'32000' ...

..this was a quite stupid mistake. Sorry about that.

With :     LH      R0,=H'32000' My program Works.

Many thanks to all .

Lolo

 
Coding your own channel programs is definitely not recommended until you hav
e
obtained a high level of expertice, maybe not even then. 

Nor is completely bypassing EXCP and writing one's own IOS device driver, an
d
utilizing the STARTIO interface.

Yet many have done so, the majority of whom utilized a document I authored i
n
1975, and which is still being utilized to this day ... THIRTY years after i
t
was written!

On Mon, 06 Sep 2004 08:45:51 -0400 "Lolobg" <laurent.mollet@bgl.lu> wrote:


:>     XR      R0,R0

Useless instruction.

:>     LH      R0,=F'32000'

Look very carefully at this instruction.

--
Binyamin Dissen <bdissen@dissensoftware.com>
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