Debbie
Well, at least you got my attention by putting "VTAM" in the title.
I tend to doubt - like Kenneth - that VTAM has got anything to do with your
problem - except that TSO and VTAM share development effort to some extent.
This is a TSO issue - not really to be described as a problem judging by
your description.
It may be that you recall that TSO provides the "three asterisks" warning
when switching from the "default" - some say "primary" - to the "alternate"
presentation space dimensions. Maybe your favourite "alternate" dimensions
are 43 rows and 80 columns and your "homegrown" panels use traditional 24
rows and 80 columns. This requires a "resetting" of the logical display
hardware and - I believe, since I don't have the facilities at hand to
demonstrate it to myself - TSO warns the user that such a change will take
place by means of the "three asterisks".
Where VTAM comes into this somewhat indirectly is that the specification of
the default and alternate presentation space dimensions is contained in the
"presentation services" field of the BIND request unit which sets up the SNA
session between TSO as the primary logical unit (LU) and whatever, typically
a 3270 emulator these days - or maybe an LU managed by a TN3270 server,
represents the secondary LU. This field is defined by the PSERVIC operand of
the MODEENT macro which created the mode table entry specified for the
session. This mode table entry is contained within the mode table specified
on the VTAM definition statement which represents the secondary LU using the
MODETAB operand . Alternatively, if there is no MODETAB operand specified,
the VTAM-supplied table ISTINCLM is used. These VTAM resources are where
VTAM comes into the picture.
In fact it may not be quite so straightforward as this. It may be that the
specification in the selected mode table entry PSERVIC field corresponds to
the code which indicates that the application, in this case TSO, should
determine the default and alternate presentation space dimensions from the
customization of the implementation of the 3270 secondary LU itself rather
than the customization having to be coordinated with the numbers in the
selected mode table entry PSERVIC field. This is almost certainly possible
with the implementation of the 3270 secondary LU used today but not every
VTAM systems programmer has introduced the revision to definitions required
to exploit this enhancement - of very many years ago.
Having said all this it is something of a puzzle that a change of behaviour
within TSO has appeared between z/OS Communications Server SNA V1R4 and
V1R7. I'm guessing that any such change would be in response to an
enhancement relating to presentation space dimensions and may have appeared
in an APAR between V1R4 and V1R7. Thus a hunt in the description of APARs
involving TSO for V1R4, V1R5, V1R6 and, possibly, if maintenance has been
incorporated into the V1R7 you are using, V1R7 might throw up the cause of
the change to behaviour I assume some finickety TSO user has brought to your
attention.
Incidentally, as I indicated above, the requirement to press "Enter"
following the appearance of the "three asterisks" when the presentation
space dimensions change is probably the *correct* behaviour and it may be
that what happened before was the *incorrect* behaviour.
If you need more help understanding what I have been talking about - or just
more help, please post again and provide more details, giving, for example,
the presentation space dimensions in use before and after the appearance of
the "three asterisks".
Chris Mason
----- Original Message -----
From: "Debbie Mitchell" <[EMAIL PROTECTED]>
Newsgroups: bit.listserv.ibm-main
To: <IBM-MAIN@BAMA.UA.EDU>
Sent: Sunday, May 20, 2007 12:25 AM
Subject: VTAM question (***)
We have just upgraded from z/OS 1.4 to z/OS 1.7. There is a slight
behaviour
difference in ISPF, however, when navigating ISPF panels. I'm 99% sure
the
change I need to make is in VTAM somewhere, but I can't for the life of me
remember where.
When going from certain panels to other (homegrown) panels, the user is
presented with *** at the bottom of the screen and must hit enter. Prior
to
the implementation of 1.7, however, the *** was not presented and the new
panel was displayed without having to hit enter.
Can someone point me to where I need to look? Many thanks in advance.
Debbie Mitchell
Utica National Insurance Group
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