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1802, A landmark device in microprocessor history

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  • Gemeny, Steve
    All, ... This is really true. Many folks simply don t realize how wide spread the use of this landmark device was. I too built an elf from the construction
    Message 1 of 4 , Feb 6, 2002
      All,

      Stewart Marshall wrote:
      > It is curious and wonderful, the appeal this
      > little chip continues to have!

      This is really true. Many folks simply don't realize how wide spread the
      use of this landmark device was.

      I too built an elf from the construction article in the late 70s. I was
      fresh out of high school and wanted a computer in the worst way. I had been
      shopping for an Altair or an IMSAI but I just couldn't come up with the
      $500+ . I was thrilled when I saw the first article on the elf and had
      parts ordered within a week.

      My copy of the August '76 PE (now ensconced in a plastic jacket) bares the
      scars of being well read and annotated during the construction. Over the
      several months, I upgraded the elf with most of the accessories in the
      following articles. Finally, being employed full time in the electronics
      field, I decided to upgrade to the QUEST Super elf. I abandoned the elf and
      it faded into oblivion and was lost. I have kept the Super Elf, fully
      equipped with 4 K of ram, the QUEST Super ROM Monitor and Tom Pittman's TINY
      BASIC, complete with all of the documentation. Presently, My Super ELF is
      operational running Tiny Basic with the newly assembled (Psudosam 18) IO
      routines blown into a fresh 2716 at 300 baud into my Pentium 133 running
      ProComm as a TTY (Oh the irony of it all).

      But that's not the end of the story...

      Being inspired by the on line activity, I have unearthed my 1802 parts from
      the basement and re-birthed the original ELF on a proper wire wrap board. I
      have been able to teach my 11 year old son about wire wrapping, memory,
      Bits, Bytes, Nibbles, Hex and Binary as well as registers and basic program
      flow.. If only for this, it was worth the effort. But I also have the
      satisfaction of recreating a significant piece on techno history. (Build
      your own now while you still can.)

      What most people think of when discussing the 1802 is the early video games.
      Most people do not realize is how significant this quirky little micro
      processor has been in the space and medical worlds.

      As I was pouring through the web, I discovered that the 1802 was the
      preferred flight microprocessor for dozens of satellites and space based
      science instrument for over a decade. As recently as 2000, the 1802 was
      relied upon as the flight processor for the Internal Housekeeping Unit (IHU)
      of an Amateur Radio Satellite, AO-40 (Ref 1).

      But the significance of the 1802 was not limited to the ham radio
      satellites, Galileo flies with 17 of them on board. Each of the 11
      instruments is controlled by an 1802. The Command Data System is comprised
      of two redundant strings of three 1802s.The 1802 is delivering real-time
      science data that is in the news NOW! ( ref 3
      <http://galileo.jpl.nasa.gov/news/release/press020115.html> ) The spacecraft
      and the quirky little 1802s have survived nearly 3 times longer than the
      design life and have endured nearly 4 times the anticipated radiation
      levels. (It's the RAD hard nature of the 1802 as much as the low power that
      makes it so attractive for space flight.) This is a true testament to the
      endurance and and significance of this little micro to the science
      community.

      But wait... There's more.

      I have recently uncovered some documentation in my employer's archive that
      suggests (I'm still waiting on some of the details to arrive) that the 1802
      was the micro of choice for the medical implant community. I have found
      studies from the early eighties describing this application and highlighting
      yet another quirky feature of this quirky processor. It seems that stopping
      the clock on most micros is bad, since the internal registers are usually
      dynamic memory. The internal architecture needs a minimum clock frequency
      to refresh these registers. The 1802 has no minimum clock frequency. The
      use of CMOS allows the registers to be static in nature and the contents are
      preserved even with no clock at all. Stopping the clock on an 1802 places
      the chip into a kind of stasis with an amazingly low power consumption... on
      the order of several NANO-WATTS in some parts. A process for screening
      production chips to identify these special parts was developed but RCA
      declined to implement it. This screening was conducted regularly, here from
      standard production runs of 1802s and these special chips were used in
      implantable medical devices until fairly recently. I don't yet know the
      specifics on these devices, I presume them to be pace makers and timed
      medication delivery devices and I don't know the quantities but presume them
      to be experimental and in the hundreds.

      While the 1802 was special for me (it set me on a rewarding career path), it
      should be special in the hearts of, perhaps, hundreds of folks who have
      benefited from having it pumping away inside them to regulate their own
      heartbeat and deliver medication. It should be special to thousands of
      scientists around the world whose research would not be possible without it.
      It should be special to tens of thousands of Amateur Radio operators who
      rely on it for the operations of the satellites they frequently communicate
      through. And it should be special to the millions of people who have
      marveled at the images of other worlds brought to them courtesy of the
      quirky little 1802.

      I really hate to see it relegated to what some have called "an odd, archaic,
      primitive micro controller" but if primitive it is... well, it works well
      enough to be in some of the most prestigious places in the solar system...
      and beyond!



      Steve Gemeny

      aa3nm@... <mailto:aa3nm@...>


      Ref.
      1) AO-40 (P3D) IMU-2 an experimental replacement for the 1802
      http://www.amsat.org/amsat/sats/phase3d/ihu2.html
      <http://www.amsat.org/amsat/sats/phase3d/ihu2.html>
      A0-40 (P#D) IMU
      http://www.amsat.org/amsat/sats/phase3d/ihu.html
      <http://www.amsat.org/amsat/sats/phase3d/ihu.html>

      2) Galileo FAQ
      http://www.jpl.nasa.gov/galileo/faqcomp.html
      <http://www.jpl.nasa.gov/galileo/faqcomp.html>
      Galileo Engineering information
      http://www.wcresa.k12.mi.us/nasa/engineer.htm
      <http://www.wcresa.k12.mi.us/nasa/engineer.htm>

      3) Galileo Current Events
      http://galileo.jpl.nasa.gov/news/release/press020115.html
      <http://galileo.jpl.nasa.gov/news/release/press020115.html>



      <http://www.amsat.org/amsat/articles/g3ruh/124.html>



      [Non-text portions of this message have been removed]
    • Lee Hart
      ... That s wonderful! Isaac Asimov said, Any sufficiently advanced technology is indistinguishable from magic. And that is what we have done with computers.
      Message 2 of 4 , Feb 7, 2002
        Gemeny, Steve wrote:
        > Being inspired by the on-line activity, I have unearthed my 1802 parts
        > from the basement and re-birthed the original ELF on a proper wire
        > wrap board. I have been able to teach my 11 year old son about wire
        > wrapping, memory, Bits, Bytes, Nibbles, Hex and Binary as well as
        > registers and basic program flow.

        That's wonderful! Isaac Asimov said, "Any sufficiently advanced
        technology is indistinguishable from magic." And that is what we have
        done with computers. We have made them so complicated that no one can
        truly understand them any more -- they have become magic.

        The trouble is, magic is enigmatic, inscrutible; not understandable. It
        deliberately complicates and obscures how things work. When you treat a
        technology as magic, you put it in the hands of the experts; "wizards"
        that have to do everything for you. You can't build it, or fix it, or
        modify it yourself.

        There are lots of problems with relying on experts. One big one is that
        you can't move ahead. Without simple examples to learn from, there is no
        way to study, improve, grow, or advance. How are future computer experts
        going to get started, if they treat computers as magic?

        The 1802 is the "bicycle" of computers. Something so simple that even a
        kid can use it, fix it, understand it, and learn how it works. Like a
        bicycle, it is an elegant combination of parts that is just enough to do
        the job, and no more. The 1802 gives you that "aha!" moment, when you
        truly understand and so are ready to advance to more complicated
        computers.

        > I really hate to see it relegated to what some have called "an odd,
        > archaic, primitive micro controller" but if primitive it is... well,
        > it works well enough to be in some of the most prestigious places in
        > the solar system... and beyond!

        I couldn't agree more!
        --
        Lee A. Hart Ring the bells that still can ring
        814 8th Ave. N. Forget your perfect offering
        Sartell, MN 56377 USA There is a crack in everything
        leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
      • Gemeny, Steve
        Group Forgive the repeat transmission from nearly 2 years ago, but given the many new members since, and the recent discussion RE: the early days of 1802
        Message 3 of 4 , Jan 19, 2005
          Group
          Forgive the repeat transmission from nearly 2 years ago, but given the many new members since, and the recent discussion RE: the early days of 1802 history I felt it appropriate to repost this one.
          Enjoy,
          Steve

          Forgive the repeat transmission form nearly 2 years ago, but given the many new members since, and the recent discussion RE: the early days of 1802 history I felt it appropriate to repost this one.
          Enjoy,
          Steve

          -----Original Message-----
          From: Gemeny, Steve
          Sent: Wednesday, February 06, 2002 5:17 PM
          To: 'cosmacelf@yahoogroups.com'
          Subject: 1802, A landmark device in microprocessor history

          All,
          Stewart Marshall wrote:
          > It is curious and wonderful, the appeal this
          > little chip continues to have!
          This is really true. Many folks simply don't realize how wide spread the use of this landmark device was.
          I too built an elf from the construction article in the late 70s. I was fresh out of high school and wanted a computer in the worst way. I had been shopping for an Altair or an IMSAI but I just couldn't come up with the $500+ . I was thrilled when I saw the first article on the elf and had parts ordered within a week.
          My copy of the August '76 PE (now ensconced in a plastic jacket) bares the scars of being well read and annotated during the construction. Over the several months, I upgraded the elf with most of the accessories in the following articles. Finally, being employed full time in the electronics field, I decided to upgrade to the QUEST Super elf. I abandoned the elf and it faded into oblivion and was lost. I have kept the Super Elf, fully equipped with 4 K of ram, the QUEST Super ROM Monitor and Tom Pittman's TINY BASIC, complete with all of the documentation. Presently, My Super ELF is operational running Tiny Basic with the newly assembled (Psudosam 18) IO routines blown into a fresh 2716 at 300 baud into my Pentium 133 running ProComm as a TTY (Oh the irony of it all).
          But that's not the end of the story...
          Being inspired by the on line activity, I have unearthed my 1802 parts from the basement and re-birthed the original ELF on a proper wire wrap board. I have been able to teach my 11 year old son about wire wrapping, memory, Bits, Bytes, Nibbles, Hex and Binary as well as registers and basic program flow.. If only for this, it was worth the effort. But I also have the satisfaction of recreating a significant piece on techno history. (Build your own now while you still can.)
          What most people think of when discussing the 1802 is the early video games. Most people do not realize is how significant this quirky little micro processor has been in the space and medical worlds.
          As I was pouring through the web, I discovered that the 1802 was the preferred flight microprocessor for dozens of satellites and space based science instrument for over a decade. As recently as 2000, the 1802 was relied upon as the flight processor for the Internal Housekeeping Unit (IHU) of an Amateur Radio Satellite, AO-40 (Ref 1).
          But the significance of the 1802 was not limited to the ham radio satellites, Galileo flies with 17 of them on board. Each of the 11 instruments is controlled by an 1802. The Command Data System is comprised of two redundant strings of three 1802s.The 1802 is delivering real-time science data that is in the news NOW! ( ref 3 <http://galileo.jpl.nasa.gov/news/release/press020115.html>) The spacecraft and the quirky little 1802s have survived nearly 3 times longer than the design life and have endured nearly 4 times the anticipated radiation levels. (It's the RAD hard nature of the 1802 as much as the low power that makes it so attractive for space flight.) This is a true testament to the endurance and significance of this little micro to the science community.
          But wait... There's more.
          I have recently uncovered some documentation in my employer's archive that suggests (I'm still waiting on some of the details to arrive) that the 1802 was the micro of choice for the medical implant community. I have found studies from the early eighties describing this application and highlighting yet another quirky feature of this quirky processor. It seems that stopping the clock on most micros is bad, since the internal registers are usually dynamic memory. The internal architecture needs a minimum clock frequency to refresh these registers. The 1802 has no minimum clock frequency. The use of CMOS allows the registers to be static in nature and the contents are preserved even with no clock at all. Stopping the clock on an 1802 places the chip into a kind of stasis with an amazingly low power consumption... on the order of several NANO-WATTS in some parts. A process for screening production chips to identify these special parts was developed but RCA declined to implement it. This screening was conducted regularly, here from standard production runs of 1802s and these special chips were used in implantable medical devices until fairly recently. I don't yet know the specifics on these devices, I presume them to be pace makers and timed medication delivery devices and I don't know the quantities but presume them to be experimental and in the hundreds.
          While the 1802 was special for me (it set me on a rewarding career path), it should be special in the hearts of, perhaps, hundreds of folks who have benefited from having it pumping away inside them to regulate their own heartbeat and deliver medication. It should be special to thousands of scientists around the world whose research would not be possible without it. It should be special to tens of thousands of Amateur Radio operators who rely on it for the operations of the satellites they frequently communicate through. And it should be special to the millions of people who have marveled at the images of other worlds brought to them courtesy of the quirky little 1802.
          I really hate to see it relegated to what some have called "an odd, archaic, primitive micro controller" but if primitive it is... well, it works well enough to be in some of the most prestigious places in the solar system... and beyond!

          Ref.
          1) AO-40 (P3D) IMU-2 an experimental replacement for the 1802
          http://www.amsat.org/amsat/sats/phase3d/ihu2.html
          A0-40 (P#D) IMU
          http://www.amsat.org/amsat/sats/phase3d/ihu.html

          2) Galileo FAQ
          http://www.jpl.nasa.gov/galileo/faqcomp.html
          Galileo Engineering information
          http://www.wcresa.k12.mi.us/nasa/engineer.htm

          3) Galileo Current Events
          http://galileo.jpl.nasa.gov/news/release/press020115.html





          Steve Gemeny
          New Horizons
          Ground System Engineer
          http://pluto.jhuapl.edu

          Business Development Manager
          Satellite Communication Facility
          Johns Hopkins Applied Physics Laboratory

          240-228-4864
          http://www.scf.jhuapl.edu





          [Non-text portions of this message have been removed]
        • whd_whd_whd
          Ouch! Sorry, I could not let this one go. (I ll try to not hold it against you) ;o) It was not Isaac Asimov, but Arthur C. Clarke, who said, Any sufficiently
          Message 4 of 4 , Jul 27 10:17 AM
            Ouch! Sorry, I could not let this one go. (I'll try to not hold it against you) ;o)

            It was not Isaac Asimov, but Arthur C. Clarke, who said,
            "Any sufficiently advanced technology is indistinguishable from magic."

            Gotta give credit where it's due, and make sure others do not propagate
            the same error, which would be a misconception of epic proportions.
            (or thereabouts)

            It is easy to get The Four Grand Masters of Science Fiction confused at times:

            Robert A. Heinlein
            Arthur C. Clarke
            Isaac Asimov
            Ray Bradbury

            (yes, in that order -- and Bradbury only listed last because he wrote
            a lot of "speculative fiction" / fantasy)


            --- In cosmacelf@yahoogroups.com, Lee Hart <leeahart@...> wrote:
            >

            {snip}

            > That's wonderful! Isaac Asimov said, "Any sufficiently advanced
            > technology is indistinguishable from magic." And that is what we have
            > done with computers. We have made them so complicated that no one can
            > truly understand them any more -- they have become magic.

            {snip}

            > --
            > Lee A. Hart Ring the bells that still can ring
            > 814 8th Ave. N. Forget your perfect offering
            > Sartell, MN 56377 USA There is a crack in everything
            > leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
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