Seibel: From your vantage point on this stone wall, do you feel there is enough going back and forth between the academy and industry?

Allen: Well, NSF published a wonderful report with a one-page graph a few years ago which showed where several billion-dollar industries come from, like graphics, the Internet, high-performance computing, transistors. These billion-dollar industries were down the y-axis and on the x-axis was a timeline showing when it started, what was the role of industry, by lab, and what was the role of academia.

Some started in industry; some started in academia. Together, these two entities had contributed pretty much equally into building these multiple billion-dollar industries. I think the real important thing is to protect the interplay so that there’s a lot of cross-channeling of ideas, and of technologies, and methods, and investments to see it continuing.

Right now, with the focus that the U.S. has on maintaining innovation, and the importance of it, I think we’re doing pretty well in terms of interaction, working together, and solving problems together. And solving the problems that keep us from solving problems—intellectual property being one of them.

Seibel: IBM is not exactly blameless there.

Allen: Not at all.

Seibel: You must have your name on patents.

Allen: No, none. Part of it is that software wasn’t patentable. The other thing was that I was often working at the leading edge of things and the best way to get it into IBM was to publish it and some other company would pick it up. I was much more interested in getting it into products than to getting a patent on things.

Seibel: So that was easier than convincing someone within IBM to build a product based on your research?

Allen: We have a much better way of doing things now. But there was a long way, sometimes, between a good idea in research and a product.

Seibel: Since receiving the Turing Award has caused you to reflect a bit on your whole career, is there anything that you’ve realized ties it all together?

Allen: I think my career and the way I do things—the one word that kind of sums it up is “exploring.” I love exploring the edges—of ideas, of projects, and the physical earth, whatever it is—people too—and that I find very exciting.

But there’s a flip side in that I’m a starter, not a finisher. I get attracted to new things. The field of compilers was just a marvelous field because the computers continued to present challenges. And the problems being solved continued to be increasingly challenging.

Bernie Cosell

In 1969 when the first two nodes of the ARPANET—the network that would become the core of the Internet—came on line, every packet that flowed over 50 kilobit/second leased lines was routed through two specialized computers called Interface Message Processors, or IMPs. The IMPs were designed and built by Bolt Beranek and Newman (BBN), and the software that ran the IMPs had been written by a team of three programmers, one of whom was Bernie Cosell, who had left MIT three years before, at the beginning of his junior year, to join BBN.

Originally hired as an application programmer on a project building one of the earliest timesharing systems, Cosell quickly moved to the systems programming side of things and was soon “czar of the PDP-1 timesharing system” responsible for finishing the operating-system code and keeping the system running.

Over a 26-year career at BBN, Cosell would work on a little bit of everything, earning a reputation within BBN as a master debugger and “fixer” who could be thrown onto a struggling project to make the software work. And he hacked just for fun: to hone his Lisp skills he wrote DOCTOR, a version of Joseph Weizenbaum’s ELIZA, based on Weizenbaum’s description in a journal article. Written in BBN-LISP, which spread around the ARPANET along with the TENEX operating system, Cosell’s version of DOCTOR also had a wide distribution—wider than Weizenbaum’s original—inspiring new implementations and related programs.

In 1991 Cosell left BBN and bought a sheep farm in Virginia, where he now lives with his wife Lynn, three dogs, innumerable cats, and lots of sheep. He does some programming for a local ISP, hacks a bit on his own projects, and teaches a few courses in programming and computer security but is glad he no longer works as a full-time programmer. Ironically, as a result of his move to the country, Cosell—one of the fathers of the Internet—now has only dial-up access from his home.

In this interview we talked about how he won his reputation as a master debugger, the importance of writing clear code, and how he convinced the other programmers on the IMP project to stop patching the binary.

Seibel: When did you first get involved with programming?

Cosell: In high school. I don’t know if it was true or not but the rumor was that our high school was the first high school in the country to actually have its own computer. IBM donated a 1620 to our high school. I think it arrived either the year before I arrived, or the year I arrived at high school in ’59.

Seibel: And what high school was it?

Cosell: Bronx High School of Science in New York. I believe the previous generation of students were using Columbia University’s 650. But the head of the math department was very pleased that he had his own computer. In fact, he was writing a book on programming and this was back when there weren’t many books on programming. I ended up debugging all of his examples. Almost the only thing I remember about high school is learning to program.

Seibel: What were you programming then? Assembly on punch cards?

Cosell: Yeah. Well, it was punch cards but the 1620 also had a console. It had an IBM Selectric typewriter that was the input/output console, and you could input programs from that. To show you the era it was, they chose not to put arithmetic hardware in it. It had table-lookup arithmetic: there was an area of memory and when you wanted to do an addition, one digit gave you the row, one digit gave you the column, and the value was there. And part of every program was loading that part of memory with the addition and multiplication tables.

So you could actually type from the typewriter but mostly we punched cards and loaded them in. There was a Fortran for it but I never did very much Fortran. Mostly, I programmed in 1620 assembler.

The other thing I learned in high school is how to wire plug boards. Someplace along the route, we had something like an old 403 calculating printers and I learned how to wire a plug board. It was such a primitive art, even at the time, but it turned out to be useful. At BBN, like ten years after I was in high school, we actually needed somebody to wire a plug board and I just said, “Oh, give me the manual on that thing.” And I read the manual and made an old standalone accounting-machine printer do a primitive protocol to serve as a line printer on our PDP-1.

Seibel: And in between high school and BBN you went to MIT?

Cosell: I graduated from high school and entered MIT in ’63. I was a solid math major at MIT, taking an odd computer course. Computers were still an occasional class taught out of the electrical engineering department; you couldn’t major in computer science. Folks were just starting to build the first time-sharing systems on the 709 or 7094, whatever they had at the computer center, but I was pretty busy doing math.

I took some EE courses and logic courses and I took the odd computer course and seemed to be OK at it. I didn’t understand what the really good programmers did because I was just a little kid. But I seemed to be able to program.