JES2 Questions



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JES2 Questions

Postby hgservers » Sun Aug 14, 2016 12:14 am

Hello,

I've got a few JES2 questions that I'm a little confused about.

- For punches... how come destinations have to be explicitly defined with a DESTID statement before using them on a ROUTECDE, as compared to a printer where you could just put anything onto a ROUTECDE for that without any sort of pre-definition for it?

- Is there any reason that a punch and a reader can't be dynamically defined to JES2? Would you really have to re-IPL each time you wanted to add new ones to the system?

- Going back to my first question... Say that I have the following definitions in my JES2PARM.

DESTID(LCLP01) DEST=PUN1
DESTID(LCLP02) DEST=PUN2
DESTID(LCLP03) DEST=PUN3
PUN1  CLASS=B,PAUSE=NO,ROUTECDE=LCLP01,SEP=YES,SEPDS=YES,
          SETUP=NOHALT,START=YES,UNIT=AB0
PUN2  CLASS=B,PAUSE=NO,ROUTECDE=LCLP02,SEP=YES,SEPDS=YES,
          SETUP=NOHALT,START=NO,UNIT=AB1
PUN3  CLASS=B,PAUSE=NO,ROUTECDE=LCLP03,SEP=YES,SEPDS=YES,
          SETUP=NOHALT,START=NO,UNIT=AB2
 


Normally, you would expect PUN1 to take LCLP01, PUN2 to take LCLP02, and PUN3 to take LCLP03. Now, say that I run the following command:

$T PUN1,ROUTECDE=LCLP02
 


PUN1 now takes work routed for LCLP02 - but this makes no sense, as the DEST for DESTID(LCLP02) is stated to be PUN2. Now this further complicates things because it makes it seem useless/unnecessary now, but if I just use DEST=LOCAL for the DESTID, no punch selects it at all, and the destination for the job just changes to LOCAL (as opposed to saying/staying as LCLP02). So why is this, and again, what's the point?

- Assuming that there really is a point to all of this, why don't we have to use this for printers, and when should we use it for printers?

Sorry if these seem like basic questions - I do understand what I need to do to make it work, but my question is just more of a "Why do we need to do it this way to make it work?"

Thanks for any insight into this! :)
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Re: JES2 Questions

 

Re: JES2 Questions

Postby Robert Sample » Sun Aug 14, 2016 6:32 am

Is there any reason that a punch and a reader can't be dynamically defined to JES2? Would you really have to re-IPL each time you wanted to add new ones to the system?
What does the manual tell you? If the manual tells you that punches and reader require an IPL then that's the reason. If the manual says you can restart JES2 to add them, then you don't have to IPL but you do have to shut down JES2 and restart it.
how come destinations have to be explicitly defined with a DESTID statement before using them on a ROUTECDE, as compared to a printer where you could just put anything onto a ROUTECDE for that without any sort of pre-definition for it?
Because that's what the manual says. IBM does NOT always give you reasons for their restrictions -- sometimes you merely have to learn to accept the restrictions.
Why do we need to do it this way to make it work?"
Because that's the way it works. Accept it and move on. If you're really lucky, sometime you might be able to find an IBMer who worked in JES2 30 - 40 - 50 years ago and knows why these things were done the way they were done and will tell you. Otherwise, you just accept them as they are and move on.

Asking why things are a certain way is not usually a productive question. Many of these decisions were made long ago, to accommodate hardware that no longer is in use (when is the last time a 2540 reader-punch was attached to a system z machine, for example?), but the actual reasons may be lost to history or they may be restricted to IBM-internal documents that you'll never see unless you go to work for IBM.
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Re: JES2 Questions

Postby steve-myers » Sun Aug 14, 2016 7:18 am

hgservers wrote:Is there any reason that a punch and a reader can't be dynamically defined to JES2? Would you really have to re-IPL each time you wanted to add new ones to the system?
As Mr. Sample says, given the virtually non-existent nature of these devices, there is is essentially no need for the capability you describe. I last encountered a real 2540 in the "wild" in the 1990s. This customer also had 557 machine and a card sorter, and ran roughly 3 boxes of cards through each machine a week. There were major issues getting service for these machines as I recall. A couple of years later an online - probably CICS - application replaced the punched card machines and that was the end of punched card machines in that shop.
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