old processor -- 8085

"rk" wrote in message
...
Hi,

Anyone out there have experience with the 8085 microprocessor? This is
the
history channel!

In any event, I understand that a new processor that implements that
instruction set is being developed for space (fpgas, asics) and that test
cases to check it out would be helpful. demunge e-mail.

Thanks,

A number of computers in early 1980s use this chip -- the Heath / Zenith
Z-100; Radio Shack TRS-80 Models 100 and 200, CompuPro 8/16 being some of
the better known models.

With the availability of the Intel Pentium processor (space rated) -- I am
curious what space application would warrant such a "new processor" -- used
for a sub-system?

w9gb

g. beat @ wrote:


With the availability of the Intel Pentium processor (space rated) -- I am
curious what space application would warrant such a "new processor" -- used
for a sub-system?



When I was digging around I found that the Mars Pathfinder mini-rover
apparently used a version of the 8085:
http://www.klabs.org/DEI/Processor/8085/index.htm

Pat

"rk" wrote in message
...
On Sat, 22 Jul 2006 07:27:42 -0500, "g. beat" @spam protected wrote:


"rk" wrote in message
. ..
Hi,

Anyone out there have experience with the 8085 microprocessor? This is
the
history channel!

In any event, I understand that a new processor that implements that
instruction set is being developed for space (fpgas, asics) and that
test
cases to check it out would be helpful. demunge e-mail.

Thanks,

A number of computers in early 1980s use this chip -- the Heath / Zenith
Z-100; Radio Shack TRS-80 Models 100 and 200, CompuPro 8/16 being some of
the better known models.

With the availability of the Intel Pentium processor (space rated) -- I am
curious what space application would warrant such a "new processor" --
used
for a sub-system?

Curious, do you have a reference for this space-rated Intel Pentium
processor?

Had to dig in archives for this - sicne this was during the Craig Barrett
leaderhsip at Intel.
http://www.eet.com/story/OEG19981209S0032
Intel reaches for new Pentium galaxies

December 9, 1998
EE Times

By Margaret Quan

In a display of good corporate citizenship that may also reflect a desire to
crack the defense market, Intel Corp. has granted a royalty-free Pentium
license to the U.S. Department of Energy's Sandia National Laboratories for
development of a radiation-hardened version of the processor for use in
satellites, space vehicles and defense systems. At a press conference at
Intel's Santa Clara headquarters, Intel president and chief executive
officer Craig Barrett quipped that it is part of Intel's plan for
"intergalactic expansion."

Barrett said Intel had three primary motives for granting Sandia a free
license to the Pentium: a patriotic allegiance to U.S. interests, a long
working relationship with the DOE on similar projects and a desire to move
technology forward in the low-volume markets for space, satellite and
defense systems.

As an exercise, you may wish to compare the area, mass, and power of such
a
processor vs. that of what is described above (0 area, 0 mass, and close
to
0 power).

Well the last fo the old radiation hardened RCA 1802 processors are long
gone -- last time I looked (AMSAT may have one flight spare left that was
not used in 1980s)

The power advantages of the old Digital (later acquired by Intel) StrongARM
processor (like the SA-1100) that was used on some space satellites in late
1990s - for example the AMSAT AO-40. Unfortunatley -- Intel gave up of the
innovative ARM design around 2001 - in favor of its Intel PXA255 and PXA26x
processor family.
http://www.intel.com/design/strong/a...x/sa1100lx.htm

g. beat

rk wrote:

That is correct. It was also on Small Explorer FAST and the Cassini
Orbiter. It's also on quite a few other spacecraft.

Going from memory (note weasle words but I don't have the notes handy right
now and insufficient time to search) these chips were all produced by Harris
Corp., it was the HS-80C85RH. This in turn was designed by Sandia National
Labs under an agreement with Intel. Also, these chips are out of production
and use high voltages and require level translators to communicate with
modern logic and memory devices. Really pushing the memory, this is old
stuff, the chip liked to have a 10V supply and the SEU immunity was
decreased at 5V. In any event, even the 5V logic interface is now pretty
much dead for new designs.


That article suggested that it had fairly impressive radiation
resistance also...I imagine the the smaller the microcircuitry in a
processor gets (today, I'd imagine you'd call it nanocircuitry) the more
harm radiation can do to it unless it is well shielded.
Everyone thinks that the ultimate microcircuit will have paths one atom
thick; that's probably not good for something that's going to be struck
by cosmic rays.

Pat

"Pat Flannery" a écrit dans le message de news:
...
resistance also...I imagine the the smaller the microcircuitry in a
processor gets (today, I'd imagine you'd call it nanocircuitry) the more
harm radiation can do to it unless it is well shielded.

Yes and no.

It's a bit more complicated.

In brief, you have to type of damaging radiation effects : Total dose and
single event effects - SEE - ( I won't go into multiple event effects ).
Among single event effects ( which are the ones you are thinking about,
based upon your post ), you can have single event upsets ( SEU ), single
event latchup ( SEL ), single event burnout ( SEB ) and single event gate
rupture ( SEGR ).

For micro-processor and controllers, the most importants SEES are SELs and
SEUs. The probability of having one for a given level of radiation ( in
number of charged particle of a given energy per surface area ) is
proportionnal to the energy needed to create the effect and to the sensitive
area in the IC.

Now reducing the circuit design actually reduces the sensitive area, so
reduces the risks ( per bit or gate i.e. at constant processing power ).
However, at the same time, modern designs also uses the reduced size to get
by with less energy for a given effect ( so less energy density, which means
less heat power, which in turn means you can pack more processing power in a
smaller area ). So the IC becomes sensitive to lower levels of energy, which
means the probability goes up. Two conflicting effects of the same cause. In
general rule of thumb ( but there are exceptions ), modern commercial
off-the-shelf circuits are more sensitive to SEEs than their predecessors,
but also have much greater capabilities ( or lower power consumption and
size ).

There are ways to protect against SEEs with modern circuitry design, but
they requires special technics or materials ( which make the component less
efficient and more expensive ) and so are not used in commercial components.
Which means that space-specific versions have to be devellopped and
manufactured, which is costly. Which is why no manufacturer does it unless
contracted by s space agency - DoD used to do it but is mostly getting away
from this -. Which is why Rad-Hard compoenent are usually 2 or more
generation older than non-rad hard Mil-qual ones ( let alone commercial
ones ).

"g. beat " @spam protected a écrit dans le message de news:
...
In a display of good corporate citizenship that may also reflect a desire
to
crack the defense market, Intel Corp. has granted a royalty-free Pentium
license to the U.S. Department of Energy's Sandia National Laboratories
for development of a radiation-hardened version of the processor for use
in satellites, space vehicles and defense systems. At a press conference
at


That's a necessity if they want to use a modern pentium in an environment
which is even moderately radioactive. According to what I've found on the
net the PIII is extremely sensitive to SEEs :

http://radhome.gsfc.nasa.gov/radhome...SREC02_W16.pdf

frédéric haessig wrote:

"Pat Flannery" a écrit dans le message de news:
...


resistance also...I imagine the the smaller the microcircuitry in a
processor gets (today, I'd imagine you'd call it nanocircuitry) the more
harm radiation can do to it unless it is well shielded.



Yes and no.

It's a bit more complicated.



Consider what's going to happen to a atomically thick nano-resistor when
a cosmic ray impacts it and starts spinning off its electrons like it
was inside the CERN collider.
If it was around a million atoms thick, then the total resistance change
via any cosmic ray impact changing the specific structure or resistance
of the electrical path or properties of the semiconductor in question is
going to be very mild indeed in regards to its conductivity. You start
doing this on the atomic scale of circuitry and one cosmic ray impact
starts degrading and changing the whole structure of the entire
microprocessor chip by changing the atomic structure and composition of
the elements that make it up. Every atom that undergoes a change of
state by high energy bombardment is going to change its physical state
into a new form that is going to have different electrical properties of
conductivity, and unless you have deigned the atomic microprocessor to
self-detect flaws and bypass them, it is going to stop the whole widget
dead in its tracks, or start giving spurious output.

Pat

"Pat Flannery" a écrit dans le message de news:
...

Consider what's going to happen to a atomically thick nano-resistor when a
cosmic ray impacts it and starts spinning off its electrons like it

Yes, but consider the probability of an 'atomically thick' nanoresistor been
struck by a charged nucleus ( that's what cosmic rays - or, more properly
GCR - are ). And that's without getting into quantic effects. We're reaching
here into physical mechanism which are not well understood ( at least as far
as I know ), as effects which are secpndary on a bigger scale can no longer
be ignored.


was inside the CERN collider.
If it was around a million atoms thick, then the total resistance change
via any cosmic ray impact changing the specific structure or resistance of
the electrical path or properties of the semiconductor in question is
going to be very mild indeed in regards to its conductivity. You start
doing this on the atomic scale of circuitry and one cosmic ray impact
starts degrading and changing the whole structure of the entire

That's multiple event upset ( which I didn't cover in my short answer ). It
goes more complicated

microprocessor chip by changing the atomic structure

You're speaking about displacement damage by radiation here. It already
occurs with current ( and out-of-date ) components. It's factored in the
total life of compoent under radiation ( as in probability ) as degradation
of component reliability and performances.

and composition of the elements that make it up.

ARe you aware of the energy needed to break atomic links? Suffice to say
that this is so unlikely there's no need to protect against this as the
probability is too low to be considered.

Every atom that undergoes a change of state by high energy bombardment is
going to change its physical state into a new form that is going to have
different electrical properties of conductivity, and unless you have
deigned the atomic microprocessor to self-detect flaws and bypass them, it
is going to stop the whole widget dead in its tracks, or start giving
spurious output.

Pat

Pat, I have to ask :

Have you designed circuitry for work in a radiation environment? or specific
rad-hard components?

Because some of what you say makes sense to me, but some doesn't, so I'd
like to lnow if you have encountered these in prior experience.

On Sat, 22 Jul 2006 18:21:55 -0500, "g. beat" @spam protected
wrote:

Barrett said Intel had three primary motives for granting Sandia a free
license to the Pentium: a patriotic allegiance to U.S. interests, a long
working relationship with the DOE on similar projects and a desire to move
technology forward in the low-volume markets for space, satellite and
defense systems.

....Of course, the running joke was that if Intel *really* wanted to
make everyone **** bricks, they should have donated the Xeon I to the
gummint. The damn thing, when stood up on end, was *very* reminiscent
of a certain 1x4x9 obsidian slab. This led to a couple of Photochopped
shots of the Monolith with Intel Inside logos plastered on.

OM
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Pat Flannery wrote:
unless you have deigned the atomic microprocessor to
self-detect flaws and bypass them, it is going to stop the whole widget
dead in its tracks, or start giving spurious output.

I guess you could build something like the Saturn LVDC: duplicate the
CPU pipeline multiple times and have a voting system between pipeline
stages so that any single failure won't take down the whole system...
the most common output value is passed on to all pipelines at the next
stage so you can get an error in one or more pipelines at each stage
and still get the correct results at the end.

Mark