Tony
So in tune with Paul's verbal abuse, mixing metaphors, he should be casting
his boulders in the direction of TSO, not VTAM since it would appear the TSO
developers have been negligent in not keeping strictly to the published TCAM
and VTAM APIs.
Apart from the minimal intervention "around the edges" which the exceptional
function supplied by VTAM in order to have local (non-SNA) channel-attached
3270 controllers (or their "look-alikes") appear to be type 0 secondary
logical units which only incidentally use the 3270 data stream, VTAM has no
interest in the *content* of the 3270 data stream. The "minimal
intervention" extends only to a mapping and transformation of the first
character in the data stream, the "write control character", to the "channel
command word" and vice versa in order to ensure that the 3270 data stream is
the same in all environments fore the benefit of the device-independent
program.
Or something like that, it's a while since I looked at it but I know that
whatever VTAM did can't have been one of your inhibitors.
Incidentally, did you ever take a look at the 3270<>Asynchronous ASCII
protocol converters such as the 3708 or 7171?
Chris Mason
----- Original Message -----
From: "Tony Harminc" <[EMAIL PROTECTED]>
Newsgroups: bit.listserv.ibm-main
To: <[email protected]>
Sent: Friday, June 15, 2007 3:30 AM
Subject: Re: Multiple TSO logons (was: Patents, ...)
On Wed, 13 Jun 2007 14:03:15 -0500, Paul Gilmartin
<[EMAIL PROTECTED]>
wrote:
Theology. Dogma. Simply to start doing it right, you must
stop doing it wrong. Somehow I feel a major culprit is VTAM
because whenever this issue arises an expert starts spouting
VTAM jargon. Get rid of VTAM; let TCP/IP connect directly to
the TMP input/output data streams.
I've looked at this, and "it isn't pretty" doesn't even begin to describe
it. Unless IBM has severely modularized things since the last non-OCO
version of this stuff, it is full of hardcoded knowledge of not only VTAM
(and TCAM!) module names, but of their various quirky behaviours.
This is one of those situations where everyone agrees that it would be a
Good Thing to replace some part of the legacy stuff, but everyone
disagrees
on just which parts are legacy junk, and which are the very core of the
architecture.
When I worked for Amdahl/Antares on Huron, we had complete control over
the
applications that drove 3270 screens, and once all the real green-screens
had gone away, it began to make sense to consider designing our own new
3270
protocol along with an emulator that would exploit it. But it never
happened, because there were just too many layers (CICS, VTAM, TSO, ...)
that all had to be fixed at exactly the same time.
Tony H.
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