from 1802 to space for one engineer


In Aug 2015 I was contacted by Gary Camp, an engineer of the 1970's who has history with COSMACs and S-100 systems - now considered "hobby" microcomputers. He worked in the 1980's at mission control for a few spacecraft including Voyager and Galileo (Galileo used several COSMACs). As an electrical engineering student in 1977, he built a COSMAC based temperature controller as a senior project; he provided documents on that system. As a mission controller at JHU/APL for the AMPTE/CCE spacecraft, he observed a number of S-100 based systems used in monitoring that spacecraft. He described these events to me in a series of emails, which I've edited as his remarks as below.

Gary has his own Web site at, and has a Web page about his NASA and APL spacecraft work.

Thanks to Lee Hart, for his review and comments on Gary's 1802 code.

- Herb Johnson, last updated Nov 1 2015.


Gary said: "I am a retired engineer and found reference to your [Web site documents] that the Voyager does not contain 1802 hardware".

"I graduated in 1977 from Cap Poly Pomona and had done my Senior project on the 1802 [as a] temperature [monitor with] conversion to Hex read out on bread board. Then I was on the Voyager Mission Control team for 3 of the 4 planetary encounters as the Data System Engineer (DSE). Later I was a JPL employee as an ACE for the AMPTE/CCE spacecraft from JHL. I was also an ACE for the entire Magellan mission including a shuttle launch; and the last part of Galileo. I have no space hardware at all [from that work]. Only pictures, documents, posters, etc. They handed them out over time. But I may have some a few books and tech docs." He then discussed details of his JHL and NASA work, and provided a scan of his senior project papers.

Mission Control

DSE is Data Systems Engineer and is a single station in the Mission Control room (just like on TV but much more bland). They monitor the health and data for the data systems in REAL time. ACE probably meant Automation and Control Engineer but even years ago, no body was sure. It is the mission controller. Responsible for the health and safety of the mission in REAL time. IE, communications links, tracking, commands to the spacecraft, etc.


As a DSE on Voyager, I monitored the data systems. I did not work on Voyager untill about 6 months before 1st encounter [in 1979]. I was a contractor off and on for 10 years on the Voyager mission, always in the DSE position. [Voyager] needed backup controllers because so many retired after the encounters were over. When they did not call me back for the last [Voyager] encounter, I hired on as a JPL employee as a mission controller on a little local satellite called AMPTE and then graduated to Magellan and Galileo.

I remember my boss [on Voyager] showing me the test bed/prototype of the electronics and it was a dense square foot of DIPs. Maybe more than one. And I do remember something about 18 bit because it was so non standard. Custom design rings a bell, too. Fragments of history [as I recall them.]

AMPTE spacecraft launched 1984, failed 1989

In the late 80s I became one of the Mission Controllers at JPL (called ACE on the radio net). JHL [John Hopkins Lab, a division of APL in Maryland] contracted JPL to manage the AMPTE/CCE spacecraft and its data. JPL had the tracking stations and the facilities to do this while JHL wanted the data for there science research on magnetic fields around Earth.

It was a very small mission as JPL missions go. maybe 6 people at JPL. We tracked the S/C every day for only 2 or 3 hours and we would upload any instructions JHL wanted to send to the S/C, and collect the previous days science data (which was sent to JHL).

We used early microcomputers for the mission control displays and commands. These were designed by JPL for in house use and were using an S-100 bus, a widely used computer back plane at the time. The processors were Z80 and we had 3 consoles in a small room with a radio net connecting us to the tracking station in Goldstone CA where all the US tracking was done for JPL. JPL had 2 more tracking stations in Spain and Australia but AMPTE used only Goldstone antennas. Later in my carrer at JPL, I contacted all 3 tracking stations daily in my position as ACE (mission Controller) for Magellan and then Galileo Deep space missions

I still might find some JPL stuff on AMPTE use of S-100 in house designed computer system. I am slowly going through old stuff to weed out the trash.

Magellan, Galileo

Magellan launched 1989 to Venus, ended 1994
Galileo launched 1989, deorbit at Jupiter 2003

[After AMPTE I] graduated to Magellan and Galileo. I was also an ACE for the entire Magellan mission including the shuttle launch.

[I served on] only part of Galileo mission, until its end. It had several 1802s and they were all extensively reprogrammed (not by me) due to the antenna failure. A long story. I might be able to contact someone at JPL though most people I knew have retired. Also, I think I may have quite a few left over moments of my 20 years at JPL If I can find them in storage.

Senior project 1975

You mentioned some interest in the period use of Cosmac. I did find the BSEE Senior project write up I did in 1975 using the 1802. Included schematics and program listing. 26 text pages hand typed and then copied with ancient copier technology of the day. I had to enter the code in bits with switches on the project board 8 data switches. I got an A on it. Took only a couple months. 1975 was about the time 1802 came out. In the cost summary, I had $30 for the CPU. Not too bad for a hot off the press processor...

Looks like I dont have the original. Now that I think about it, I think I modified the design for a guy to use as a cable continuity checker. He was ohming out each of 7 lines in a harness which was time consuming so I suggested he use the 1802 to quickly test them. I told him to make the cables twice as long and put a single connector on each end so he could just plug them in and then cut in half.(only one end needed a conn.) . So I sold my first (second?) design.

Now I have to scan in 26 pages and send them. Quality is not so good on the old copies. - Gary Camp

Note: I processed the scanned pages, produced text documents and images. Gary and I edited the text. I produced this HTML document of Gary Camp's senior project with the 1802 in 1977. - Herb

edited and published by Herb Johnson, New Jersey, USA
from discussions by Gary Camp
here's how to email and order @ me

Copyright © 2015 Herb Johnson