OK, I'll bite.

zTPF,TPF,ACP, IPARS,PARS,SABRE are all IPL'able operating systems dating
back to the 1950's, but in continuous development since then. PARS and
SABRE originally ran on the IBM 7090(??). PARS was ported to run on the
System 360. IPARS,PARS and SABRE all have their operating system and
application code thoroughly intertwined.  In addition there was ALCS which
allowed PARS applications to run under MVS.

SABRE was written for American Airlines.  PARS and later, on the other
hand, were offered generally to any airline.  Originally PARS (and SABRE)
was designed for flights within the US.  Later it was extended to (just)
handle flights between the US and Western Europe.  Far East, Japan,
Australia? Forget about it.  PARS could not handle flights taking off and
landing on different dates (the international date line problem), so it was
rewritten as IPARS. A side note: one technical challenge IBM has with
developing SABRE was where to store the data - the solution was to invent
the disk drive (RAMAC).

IPARS/PARS (and I presume SABRE) had no clear boundary between application
code, system code and the file system.  All code ran key 0, supervisor
state and had weird limitations (code objects could not exceed 800 bytes,
for instance) and all records had to be certain fixed sizes. Later
separated out the operating system and file system components as ACP and
the application code as PARS. ACP provided a lot of new features (code was
allowed to be upto 4KB in size), also it ran in supervisor state with the
application code in problem state. ACP became TPF when Bank of America
started using it, and later zTPF.

All versions of ACP,IPARS,PARS and SABRE were shipped as source code.  All
airlines heavily modified the source and bought sold the modifications
among themselves.  This continued when TPF (an OCO product was released),
but was limited to the application code.  So with ACP/IPARS/PARS you are
looking at the original open source code.  The early versions of the code
were public domain, but it pretty quickly became copyrighted, and that by
the 1980's the intertwining of the copyright was already an issue.

----
Matthew Donald

On Sun, Oct 21, 2012 at 12:45 PM, Shmuel Metz (Seymour J.) <
[email protected]> wrote:

> In <22812F8E8B2542AC95AEDBCD8E53A58B@asus>, on 10/17/2012
>    at 09:46 PM, T Gold <[email protected]> said:
>
> >I came here to find anyone in public or private that wants to talk
> >about pars, ipars, tpf and or apc or all of the above.
>
> You already got an explanation of LPAR and TPF. Note that Airline
> Control Program (ACP) is the OS for TPF. This is an appropriate venue
> to discuss the IBM software, but probably not airline and bank
> software running under TPF or the specifics of a customer-vendor
> dispute.
>
> >In short it mostly seems to "be IBM".  Recent statements by the
> >major GDSs  are that their problems are "IBM's fault".
>
> They might be telling the truth, but they have an incentive to make
> the claim even if it's false.
>
> >I've love to see IBM follow that up with a statement in the manner
> >of "Stop using our code or be  subject to legal penalties".
>
> I doubt that there's a contractual basis for yanking the license. Even
> if IBM sued for libel and prevailed, I'm confident that they'd have to
> continue licensing z/TPF on the same terms as for other customers.
>
> >Is Pars or Ipars an actual operating system?
>
> PARS is an application running under ACP. An LPAR is a virtual machine
> managed by the PR/SM feature of an IBM processor, which started as the
> CP component of VM.
>
> --
>      Shmuel (Seymour J.) Metz, SysProg and JOAT
>      Atid/2        <http://patriot.net/~shmuel>
> We don't care. We don't have to care, we're Congress.
> (S877: The Shut up and Eat Your spam act of 2003)
>
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