Re: SAA Historical perspective and education

["James W. Kilgore" <qappdsn@xxxxxxxxxxxxx>]

Dare,

Since noone else has answered it, I'll give it a try.

For starters SAA stands for Systems Application Architecture and was
introduced in 1987.

SAA was intended to be an application design model to permit the
application to run on more than one platform.  (IMO, the biggest problem
with SAA is that it had go lowest common denominator, so no external
files)

The OS/400 operating system displays some of the SAA concepts.  The
Common User Access (CUA) was a set of guidelines for display components
and general layout along with common function key assignments.  It is
because of SAA that both the AS/400 and most DOS based PC programs used
F3 to exit.

It also explained IBM's command naming convention of action-object and
recommended that applications used the object-action syntax to not only
avoid potential conflicts, but to avoid "modes" when working with files.

It defined the components of data entry panels and the "WRK" display
panels.  Even back in 1990 IBM published Red Books on how to have menu
bars and drop down menus and pop up windows long before they were
available DDS keywords.  The idea was to make a green screen look and
behave as close as possible to a DOS PC session.

One of the goals of SAA was to break a program model into "Distributed
program logic, Distributed data, and Distributed presentation and
dialog".  To me, this sounds pretty much like what we are all still
trying to do.

There were also guidelines on how to structure your code for isolation
to facilitate replacement at a future time.  Things like display file
indicators.

At that time, the AS/400 folks were not about to give up the things that
were near and dear to them like external file definitions, a REFFLD in
DDS that was lacking in SQL and subfiles.

Now that lack of the above is not earth shattering, it's pretty much
what everyone lived with on the S/36.

And that is what made SAA die on the vine.  For S/36 shops they wanted
what the AS/400 had to offer, the mainframers weren't getting anything
new and who used RPG on OS/2?

HTH


"Dare @ Work" wrote:
>
> Bob, Hans and rest
>
> I should have known with my 12 years on AS/400.
> Could someone lecture me on SAA. What is it? How is it used? What are the
> Pros and Cons? What happen to it?
>