20 Oct
2011
20 Oct
'11
11:03 a.m.
From: Dave McGuire <mcguire at neurotica.com>
On 10/18/2011 04:15 PM, Rich Alderson wrote:
Vintage Coder wrote:
>> When people wanted to port the IBM OS family
to x86 they wrote Hercules
>> to emulate the hardware. The OS doesn't make sense on anything but
>> System/360, 370, 390, Z, etc. It was easier to port the hardware than
>> the software.
>
> When IBM wanted to port the IBM OS family to POWER, they did the same
> thing. (Z, in your list above.)
I have no idea what you mean with this statement. AIX and OS/400 got ported
to POWER but they were never based on S/360 or its descendants. AIX as a
UNIX-like OS was probably never tightly coupled with the hardware, so it
could be ported easily. I believe OS/400 started out with S/34 and 36 and
grew into iOS now running on POWER. I don't know how tightly coupled those
OS were or how hard it was to port but none of the MVS could ever run
on anything but the original architecture they were designed for.
The phrase "IBM OS family" without further context is understood to mean
the MVS family of which Z/OS is a member, because MVS is IBM's flagship OS
and the oldest OS still in production and being marketed and developed as
far as I know.
With reference to your other post, I understand the difference between
public domain and open source and GPL and all that stuff. I'm not going to
attempt discuss the issue any further since certain people on this list
seem to make careers out of nitpicking and arguing for no obvious reason.
Have a ball, you're in my killfile now, but don't let that stop you since I
know you like hearing yourself talk.
On this specific issue so far none of you guys have any more facts than
I do about what happened *when* it happened. I admit, I wasn't there and I
was saying what I heard and read. Could be it was wrong, but the world isn't
going to come to an end because of my post and it could have been
discussed in a friendly way instead of jumping on people. If somebody was
actually a sysprog *at the time in an IBM shop* and can tell what was
released and when they started copyrighting things, then great. My latest
info is MVS 3.8 was the last non-copyrighted version and after that it was
strictly for licensed customers and source was generally not available. It
is not clear people were permitted to give it away when they got copies
from IBM on earlier releases. That's just more
useless conjecture.
Now for Dave's comment:
Hey Rich...If you're suggesting z/Series
machines are based on POWER
processors, please provide some references. Everything I've ever seen
about them (including rooting around inside the z890 in the next room)
says they're completely self-contained with their own CPU implementation
family. Lots of people have suggested that modern IBM mainframes are
somehow built around RS/6000 chipsets with different microcode, but have
never been able to back up those claims.
(not trying to be argumentative, and would happily stand corrected,
but I keep hearing people make this statement and then fall silent when
asked to prove it)
-Dave
Dave, as you thought, System Z is not based on POWER and has nothing to do
with it. There are a lot of people who don't know what a mainframe is and
make the mistake of thinking a big server (POWER) equals mainframe. I have
heard this before also, but never from anybody who knows anything.
All the systems I listed are based on a common, evolving architecture that
is totally different from, and incompatible with POWER. Just look at the
processor manuals for POWER (which is just a standard by the way, and
anybody can make one) and System Z which IBM actually makes. There's
nothing in common.