The story of the team behind the chip that launched a revolution
Harry Bawcom Layout Designer
Harry Bawcom was one of the team of eight Motorola employees and engineers who worked on the 6800 microprocessor and left the company in 1974 to work at MOS Technology along with Wil Mathys, Rod Orgill, Ray Hirt, Mike Janes, Terry Holdt, Chuck Peddle, and Bill Mensch.
Harry then served as a layout designer of the 6502 microprocessor. The following Q & A recounts his time and efforts at Motorola, MOS Technology, and elsewhere.
Q & A with Harry
Harry, as you were one of the team of 8 that left Phoenix for MOS Technology, what was your background before you started working at Motorola? I attended Harding College in Searcy, AR and New Mexico State University in Las Cruces, NM. While I finished 120 semester hours, and 100 hours towards a Bachelor’s in Mechanical Engineering, I did not finish the degree program.
You were one of several Layout Designers for the 6502. Can you describe what that job entailed? In the 1970s much of what today is done by computer had to be done by hand. In the case of the 6502, once the design of the chip was completed by the team that worked on the chip's architecture, that schematic was given to the design layout team. It was our job to create a topological layout from that schematic, a layout of all the transistors which made up the 11 or so glass reticles, also called "masks" that were then used to create the chip.
What challenges did you face creating the 6502 layout design with the technology that existed in the early 1970s? Design rule checking (the physical spacing between metal stripes: too close together and they will always short out in manufacture, making the chip non functional) and verifying schematic to layout was all manual. It was done by coloring a plot with colored pencils again and again as coloring a plot guided your eye to notice incorrect spacings or design rule violations.
Part of the process involved drawing the chip on plastic (stabilene) because paper was not dimensionally stable. The drawings were divided into cells at such a scale a chip would actually fill a room.
How long did this process take? Weeks. Completion was when you went several days without finding an error. If you found an error you kept at it for several more days.
Any other thoughts about the layout design of the 6502 you'd like to share? The main design emphasis for the 6502 was function and chip size. Chip size was most important because it affected the cost to build which affected selling price which was numero uno in importance. They even discarded some function to get chip size.
What led you to eventually leave MOS Technology? In 1975 several companies were trying to develop microprocessors when MOS Technology made it's splash with the MOS 6502. One of those was Digital Equipment Corporation (DEC) in Boxborough, MA. They had a much larger budget but were having much less success: they had unlimited money but could not get a chip to work:"We cannot accept new designs, the fab is full trying to get old ones to work with correction after correction."
In 1976, I got the call and since my work on the 6502 was done and I was losing the political wars at MOS Technology, I moved to Boxborough, MA to work at DEC.
You eventually left DEC to go back to work at Motorola. What led to that job change? DEC was having a difficult time. It didn't take long to realize that despite a much greater budget DEC couldn't match the accomplishment of Chuck's small team in Valley Forge, Pennsylvania. They needed more than just my skills. I remember the DEC fab refusing new chip designs because they were too occupied trying to making those already in the line functional.
I called a previous boss at Motorola and said I would be ready to come back in a year if something came up so I didn't want to freeze my butt off in Boston the rest of my life. He called right back and said come now. No interview. Just get here. He was in a different department than the 6800 project and he didn't care about the lawsuit problems.
What was it like to return to Motorola given that you had not only left Motorola for MOS Technology, but in light of the fact that Motorola eventually sued MOS Technology? After the entrance interview was completed with HR I said "What about that lawsuit?" He says "What lawsuit?" I said "Oh, nothing" that was all that was ever said. No one ever asked anything more about it. It was embarrassing to leave DEC after only 8 months but the half life of a Motorola manager was measured in months so that fact that there was one there that wanted to hire me meant I had to move fast. With the lawsuit against MOS Technology and the MOS 6502 design team no other Motorola manager would be willing to hire me. It was now or never and I still owned a place to live in Phoenix so moving back made sense.
When I got back to Phoenix, the lawsuit was a big thing to Motorola with postings on hallway bulletin boards but the digital bipolar side of things, my new department, didn't care.
I don't know what the background rumblings were on my return, certainly there were some. When I crossed the court yard to visit those remaining from the 6800 design effort they were dumb struck. It was a fine moment!
I stayed with Motorola on it's downhill slide transferring to the RF side of things. I was one small cog in making RF transistors for cell phones and base stations.
What do you recall about the lawsuit Motorola filed against MOS Technology? I remember part of the Motorola lawsuit was about the speed of creation of the 6502, particularly the layout. Though I don't have a copy of the lawsuit, my memory says that a major point of the lawsuit was that we stole the layout and did not create it anew. This is because a major problem chip designers had in that era was getting a design through the bottleneck of layout. And though it took seven man years for the 6800 (I came in at the end of the 6800 project), it only took one man year for the 6502, therefore we had to have stolen the layout. We did not. Speed was my skill. You could hire a good engineer by looking at his education and accomplishments. Layout was more of an art and a difficult problem for chip design managers and engineers to solve. Today it is done by computer.
I expect it is true that no other company developed a process and completed a successful microprocessor design as quickly for as little money as Chuck and MOS Technology did. Many tried. I think DEC failed. I had offers from Harris and Texas Instruments when I moved back to Phoenix.
As for the actual manufacturing processes behind the chip, I have no knowledge of that. But I do know that when it came to the design team on the 6502, Chuck gets the credit for that 'cause he put an amazing team together. In fact, the reasons for the success of the 6502 project are many starting with Chuck and Wil's architecture, Rod Orgill's schematic design, the fact that layout was not a bottleneck but quickly and accurately done, and the error checking successfully done without the aid of computers: every stage of the design process was a success.
Are there any other memories you would like to share? We were permitted to put our initials on the 6502 chip. A friend from Motorola days had moved to DEC and was looking through a microscope, saw the initials, and said "I know the dude!"
Being a part of the team that created the 6502 must be very gratifying. Did you realize at the time that you were making history? Back then, I had no clue what the microprocessor would bring. At the time, anyone I knew that messed with computers played Pong. I saw no future in Pong and had no clue what was to come. My true passions were motorcycles and flying.
While at DEC those few months I purchased a 1960 Cessna 150 airplane and got my pilot's license. The day after I got my license I flew to Pennsylvania, picked up Wil Mathys, a more experienced pilot than I, and flew to Phoenix via Arkansas where Wil flew home, commercial. Soon the Cessna wasn't enough airplane for me at 100 mph and also because it had difficulty crossing mountains. It took seven years but I built a 200 mph airplane that could fly as high anyone needed, even out west. It was a Rutan Long-EZ with tandem seating, a pusher engine and a front wing called a canard.
During that time I married a widow with seven children who also shared my love of flying. We had his and her airplanes. We spent spring weekends in Utah, summer weekends in Colorado and winters in Phoenix, the best of three worlds.
Today, as I sit typing on an iPad with a broadband cell connection in remote Colorado, I think who knew? Certainly not I. Thanks, Chuck, it has been a good ride.
What is your life like today? Judy and I joined the RV world when the Long-EZ started flying. Judy passed away in 2016. She had 20 years of retirement and we had 8 retirement years together. Thirty one year's total. Since Judy's passing, I divide my time parked, in my RV, between three places: Borrego Springs, CA, Moab, UT, and Silverton, CO.
With 400,000 miles on motorcycles, 120,000 miles in the Cessna, and 250,000 in the Long-EZ I finally got my degree - it is a Ph.D. in play.