Definitive S/370 Feature List (Re: ICM & STCM) 
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 Definitive S/370 Feature List (Re: ICM & STCM)

*snip*

Quote:
>Anyway, I just don't believe that anyone is using 360s anymore, 370s maybe,

I don't know if this true, but I have been told by a couple of different
people that 370's are used in the Air Force's AWACs planes.  Reason
being that core memory is immune to EMP and therefore would continue to
function in a nuclear conflict.

----
Jeff

"Hiroshima 45, Chernobyl 86, Windows 98"



Wed, 07 Feb 2001 03:00:00 GMT  
 Definitive S/370 Feature List (Re: ICM & STCM)
Not very likely.  The _only_ /370s that used core memory were the 155 and
165, and I do not believe either one would fit in a C-135 airframe.
Even if a 155 could be shoehorned in, could the electrical system take
the load, and the AC handle the cooling?  And, don't forget the 3330s and
other peripherals.  As for a 165, it also needs plumbing, a serious heat
exchanger, and some sort of 400 hz power supply.  You can draw your own
conclusions.

And, pray tell, how is core memory going to be more resistant to EMP?
The M stands for Magnetic, and core memory is just a magnetic field
established around the core.


Quote:

>*snip*
>>Anyway, I just don't believe that anyone is using 360s anymore, 370s maybe,

>I don't know if this true, but I have been told by a couple of different
>people that 370's are used in the Air Force's AWACs planes.  Reason
>being that core memory is immune to EMP and therefore would continue to
>function in a nuclear conflict.

>----
>Jeff

>"Hiroshima 45, Chernobyl 86, Windows 98"

-- Steve Myers

The E-mail addresses in this message are private property.  Any use of them
to  send  unsolicited  E-mail  messages  of  a  commerical  nature  will be
considered trespassing,  and the originator of the message will be  sued in
small claims court in Camden County,  New Jersey,  for the  maximum penalty
allowed by law.



Thu, 08 Feb 2001 03:00:00 GMT  
 Definitive S/370 Feature List (Re: ICM & STCM)
I had heard that some modern combat aircraft do have iron memory, maybe
it's just little iron as against the trusty "Big Iron", but the reasons
given are something along the lines that modern chips can be easily
wiped under the right/wrong circumstances.

Don't ask me any more.  Hell, I use Assembler, I don't build the damned
machines.

--
Charles F Hankel   Wirral   UK
------------------------------
Ready, Willing and (avail)Able



Thu, 08 Feb 2001 03:00:00 GMT  
 Definitive S/370 Feature List (Re: ICM & STCM)

Quote:

>Not very likely.  The _only_ /370s that used core memory were the 155 and
>165, and I do not believe either one would fit in a C-135 airframe.
>Even if a 155 could be shoehorned in, could the electrical system take
>the load, and the AC handle the cooling?  And, don't forget the 3330s and
>other peripherals.  As for a 165, it also needs plumbing, a serious heat
>exchanger, and some sort of 400 hz power supply.  You can draw your own
>conclusions.

>And, pray tell, how is core memory going to be more resistant to EMP?
>The M stands for Magnetic, and core memory is just a magnetic field
>established around the core.



>>*snip*
>>>Anyway, I just don't believe that anyone is using 360s anymore, 370s maybe,

>>I don't know if this true, but I have been told by a couple of different
>>people that 370's are used in the Air Force's AWACs planes.  Reason
>>being that core memory is immune to EMP and therefore would continue to
>>function in a nuclear conflict.

>>----
>>Jeff

>>"Hiroshima 45, Chernobyl 86, Windows 98"

>-- Steve Myers

>The E-mail addresses in this message are private property.  Any use of them
>to  send  unsolicited  E-mail  messages  of  a  commerical  nature  will be
>considered trespassing,  and the originator of the message will be  sued in
>small claims court in Camden County,  New Jersey,  for the  maximum penalty
>allowed by law.

I'm hardly an expert but even if system disruption occurred, I think the core
computers (as with valve radios that the USSR used in jet fighters reputedly)
could be usable after E-M side of nuclear explosions had died down.  If they
are anywhere near a nucleus explosion, the E-M effects will overload semi-
conductor electronics and "burn them out" (well, more so that valves and core,
anyway).  That's my theory.....

Cheers,
Greg



Fri, 09 Feb 2001 03:00:00 GMT  
 Definitive S/370 Feature List (Re: ICM & STCM)

Quote:

>Not very likely.  The _only_ /370s that used core memory were the 155 and
>165, and I do not believe either one would fit in a C-135 airframe.
>Even if a 155 could be shoehorned in, could the electrical system take
>the load, and the AC handle the cooling?  And, don't forget the 3330s and
>other peripherals.  As for a 165, it also needs plumbing, a serious heat
>exchanger, and some sort of 400 hz power supply.  You can draw your own
>conclusions.

A little off the subject, but the space shuttle Challenger that
exploaded and crashed in 1986 had a military computer which used
magnetic core memory. About a year afterward the IEEE Spectrum magazine
had an article on the crash. An IBM lab in Pheonix took the (rather
thoroughly drowned) computer and recovered all its memory.

A few years earlier, Byte magazine had a neat article about a hardware
hacker who got some core memory and hooked it up to his hombrew 8080
computer. He stored a basic interpreter in the 4K memory, turned
everything off, and after power on everything worked.

john alvord



Sat, 10 Feb 2001 03:00:00 GMT  
 Definitive S/370 Feature List (Re: ICM & STCM)

Quote:

(snip)

> A little off the subject, but the space shuttle Challenger that
> exploaded and crashed in 1986 had a military computer which used
> magnetic core memory. About a year afterward the IEEE Spectrum magazine
> had an article on the crash. An IBM lab in Pheonix took the (rather
> thoroughly drowned) computer and recovered all its memory.

> A few years earlier, Byte magazine had a neat article about a hardware
> hacker who got some core memory and hooked it up to his hombrew 8080
> computer. He stored a basic interpreter in the 4K memory, turned
> everything off, and after power on everything worked.

This is a characteristic of core memory - it was possible to restart a
program after a power failure because memory contents had been
preserved. It wasn't trivial, but it could be done.

About core surviving EMP, I saw an article on exactly that topic in
"Newsweek" 3-4 years ago. The article said that it was one of the
advantages of the older technology (of course, nothing near ground zero
survives) - we're talking about surviving the pulse that is created.

Bill {*filter*}



Sat, 10 Feb 2001 03:00:00 GMT  
 Definitive S/370 Feature List (Re: ICM & STCM)

Quote:


> (snip)

> > A little off the subject, but the space shuttle Challenger that
> > exploaded and crashed in 1986 had a military computer which used
> > magnetic core memory. About a year afterward the IEEE Spectrum magazine
> > had an article on the crash. An IBM lab in Pheonix took the (rather
> > thoroughly drowned) computer and recovered all its memory.

> > A few years earlier, Byte magazine had a neat article about a hardware
> > hacker who got some core memory and hooked it up to his hombrew 8080
> > computer. He stored a basic interpreter in the 4K memory, turned
> > everything off, and after power on everything worked.

> This is a characteristic of core memory - it was possible to restart a
> program after a power failure because memory contents had been
> preserved. It wasn't trivial, but it could be done.

> About core surviving EMP, I saw an article on exactly that topic in
> "Newsweek" 3-4 years ago. The article said that it was one of the
> advantages of the older technology (of course, nothing near ground zero
> survives) - we're talking about surviving the pulse that is created.

> Bill {*filter*}

In the 70's I worked in a shop that after any crash or power failure
they would IPL a stand alone program that searched through core on the
MVT system and closed off all files that were OPEN at the time of the
crash. This was part of there backup/recovery system. Real hadny trick
for journal data sets.

--

Beyond Software, Inc.       http://www.*-*-*.com/
"Transforming Legacy Applications"



Sat, 10 Feb 2001 03:00:00 GMT  
 Instruction Set Evolution

Quote:
>> This is a characteristic of core memory - it was possible to restart a
>> program after a power failure because memory contents had been
>> preserved. It wasn't trivial, but it could be done.

At one time 360 architecture had a power fail interrupt.  I think the thought was
that you could freeze processing faster than the power would totally be lost
and continue with memory intact after power was restored.  I don't know if this
was ever really used.


Sat, 10 Feb 2001 03:00:00 GMT  
 Instruction Set Evolution

Quote:

>At one time 360 architecture had a power fail interrupt.  I think the
thought was
>that you could freeze processing faster than the power would totally be
lost
>and continue with memory intact after power was restored.  I don't know if
this
>was ever really used.

you mean you never used the BPO (Branch on Power Off) instruction?  <g>

Judy Anderson
Product Development
Advanced Software Technologies Company, Ltd.



Sat, 10 Feb 2001 03:00:00 GMT  
 Instruction Set Evolution

[...]

Quote:
>In the 70's I worked in a shop that after any crash or power failure
>they would IPL a stand alone program that searched through core on the
>MVT system and closed off all files that were OPEN at the time of the
>crash. This was part of there backup/recovery system. Real hadny trick
>for journal data sets.

Maybe so, but it in the case of a system crash it seems counter
to the long-standing IBM philosophy that dictates _not_ flushing
unwritten buffers during the quasi-CLOSE performed during
abnormal termination.  How do you know that buffer contents are
reliable?

/b
--
Bill Manry  -  IBM Products Division  -  Oracle Corporation USA
These are my opinions, not necessarily Oracle's.



Sun, 11 Feb 2001 03:00:00 GMT  
 Instruction Set Evolution
The job is tougher than it initially appears.

I agree it is not a wise idea to flush a partially filled buffer.  However,
writing a tape mark and trailer labels (on tape), or a "file mark" on the
track after the most recently active track for a sequential data set is a
big step forward in recovering the data.

This type of program becomes much more difficult in OS/VS2 R1 and nearly
impossible in MVS and more recent systems.

Quote:


>[...]
>>In the 70's I worked in a shop that after any crash or power failure
>>they would IPL a stand alone program that searched through core on the
>>MVT system and closed off all files that were OPEN at the time of the
>>crash. This was part of there backup/recovery system. Real hadny trick
>>for journal data sets.

>Maybe so, but it in the case of a system crash it seems counter
>to the long-standing IBM philosophy that dictates _not_ flushing
>unwritten buffers during the quasi-CLOSE performed during
>abnormal termination.  How do you know that buffer contents are
>reliable?

>/b
>--
>Bill Manry  -  IBM Products Division  -  Oracle Corporation USA
>These are my opinions, not necessarily Oracle's.

-- Steve Myers

The E-mail addresses in this message are private property.  Any use of them
to  send  unsolicited  E-mail  messages  of  a  commerical  nature  will be
considered trespassing,  and the originator of the message will be  sued in
small claims court in Camden County,  New Jersey,  for the  maximum penalty
allowed by law.



Sun, 11 Feb 2001 03:00:00 GMT  
 Instruction Set Evolution

Quote:


> [...]
> >In the 70's I worked in a shop that after any crash or power failure
> >they would IPL a stand alone program that searched through core on the
> >MVT system and closed off all files that were OPEN at the time of the
> >crash. This was part of there backup/recovery system. Real hadny trick
> >for journal data sets.

> Maybe so, but it in the case of a system crash it seems counter
> to the long-standing IBM philosophy that dictates _not_ flushing
> unwritten buffers during the quasi-CLOSE performed during
> abnormal termination.  How do you know that buffer contents are
> reliable?

IBM provided the standalone program for IMS to close out its log tapes
after a power failure, so it must not have been counter to IBM philosopy
at the time.  IMS did get caught with there shorts down when bipolar
memory came out on the 370/145.  Their recommended recovery with the
standalone program no longer worked, and they had to take an APAR on it.
Interesting hardware dependency in software design.

Bob



Sun, 11 Feb 2001 03:00:00 GMT  
 Instruction Set Evolution

Quote:

>   Evidently, the CPU,
> registers, etc. were all solid state and the memories were core, at least
> for the S360.

This was model dependent.  In some of the lower end models, the
registers were core, also.

Bob



Sun, 11 Feb 2001 03:00:00 GMT  
 Instruction Set Evolution

Quote:

> >At one time 360 architecture had a power fail interrupt.  I think the
> thought was
> >that you could freeze processing faster than the power would totally be
> lost
> >and continue with memory intact after power was restored.  I don't know if
> this
> >was ever really used.

> you mean you never used the BPO (Branch on Power Off) instruction?  <g>

> Judy Anderson
> Product Development
> Advanced Software Technologies Company, Ltd.

Never heard that one, but I *do* know that one OEM had
a processor (the machine's nomenclature had a V and a 6
in it) that incorporated the HCF instruction.
(Halt and Catch Fire) Caused a halon discharge where I
was working. Loads of fun!

While we're on bizarre and abnormal instruction sequencing
and the like, does anyone remember the two-instruction
sequence on 360/40's that could only be halted by a poower
off?

--
Bill



Sun, 11 Feb 2001 03:00:00 GMT  
 
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