Ryan Peterman · Ryan Peterman · Transcript & summary by WhipScribe
It is a short, first-hand account of how Unix, sort, diff and Hamming's view of computing came out of a few people at Bell Labs, told by someone who worked beside them.
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“Because he's a boatload smarter than you and I put together.” Brian Kernighan · at 1:20 — open in the transcript →
In a six-minute clip from Ryan Peterman's interview series, Brian Kernighan is asked which Bell Labs colleague impressed him most technically. His first answer is Ken Thompson, and the evidence is the first version of Unix, built in 1969 on an obsolete PDP-7 with about 8K words of memory, probably in assembly language and loaded onto the machine by paper tape, with no internet to look anything up.
Kernighan then widens the picture to two other figures who shaped the labs in different ways. Doug McIlroy, his first internship boss and outside thesis reader, appears as a prolific builder, credited with Unix sort and diff, an early PL/I compiler and the idea of macros, but above all as the constructive critic who made other people's work better, Thompson's included. Dick Hamming appears as a strategist about status, who held a department head title with nobody reporting to him.
The common thread is that Bell Labs ran on a handful of people working far above the norm, and that their influence came as much from judgment and position as from raw output.
Computer scientist who spent his career at Bell Labs, starting as an intern under Doug McIlroy in 1967, and worked alongside Ken Thompson and Dick Hamming.
Brian Kernighan told Ryan Peterman that Ken Thompson is certainly the best programmer he has ever met, and called him unparalleled. Kernighan said Bell Labs had several people with untouchable technical skill, but Thompson was the obvious first name, and he pointed to the first version of Unix as the example of someone who is off the scale at what he does.
According to Brian Kernighan, Ken Thompson had been experimenting with disk scheduling on an obsolete PDP-7 with about 8K 18-bit words of memory. When his wife took their young son to California for three weeks in 1969, he used the time to write an editor, an assembler and an operating system by himself. Kernighan believes he wrote it in assembly, probably edited the code on another machine that had a text editor, and carried paper tapes over to load onto the PDP-7.
Brian Kernighan described Doug McIlroy as exceptionally good at almost anything he chose to do. McIlroy wrote the Unix sort and diff programs, did his own language design, wrote one of the first PL/I compilers and invented the idea of macros. Kernighan rated his biggest role as constructive technical critic: as the department head over Ken Thompson he never told Thompson what to do, but his criticism made the work better throughout his Bell Labs career.
Brian Kernighan said Dick Hamming worked hard to get the title of department head at Bell Labs while having no one report to him. The title carried clout he could use, since people at the wrong level in an organization get ignored, but it spared him the administrative work of managing staff. Kernighan noted that the rank showed in small ways, such as the carpet on Hamming's office floor and his listing in the phone book.
Our own transcript of the public episode, with a timestamp about every 90 seconds. Tap a timestamp or the link button on a paragraph to copy a link that opens this page there.
0:00You worked with so many legendary people. Was there anyone that, I guess, or any story of someone who kind of impressed you the most where you thought, wow, their technical chops are just untouchable? There are several like that. Ken Thompson's the obvious one. I think certainly the best programmer I've ever met, uh, unparalleled. And the story is the other first version of Unix where he's got this little old PDP seven, which is an obsolete machine has something like eight K 18 bit words. So it's, you know, tiny little machine. Um, and he's been fooling around with something to drive the disc on it. And he's thinking about, you know, how do you schedule disk operations so that it'll go fast and stuff like that.
0:50And his wife takes their young son off to California for three weeks. And he thinks, I could do something here. And so in three weeks, he builds himself an editor and assembler and an operating system. And there you have it. By himself? Yeah. Oh, you have it. By himself? Yeah. Oh yeah, absolutely. When I used to write something, you go to, you know, Stack Overflow or you kind of like look up how to write the code and then you write it. How, how does he do it without all that internet resource? Because he's a boatload smarter than you and I put together. And this is before any of that stuff existed, right? This was 1969. And so he's probably writing the code in assembly language, bear in mind, not in high-level language.
1:35And he's doing it probably on some other machine just because it has some kind of text editor. And then he's making paper tapes that he carries to this tiny little machine and loads them and sees what happens. Oh, my God. Yeah. So it's going back into the mists of time, but three weeks and he's got a working operating system. So I think that is a good example of somebody who's just off scale good at what they do. And there were a lot of people like that at the labs. Yeah, I mentioned Doug McElroy a number of times. He was my first internship. He was notionally my boss, and he was interested in storage allocators, ML, that kind of thing. And so he set me to working on something, and I almost instantaneously went somewhere else.
2:26And he didn't care. So I spent the summer doing something unrelated to that. And it seemed like it was fine because I got a come back next summer kind of offer. But he was the kind of guy who was exceptionally good at pretty much anything he wanted to do. I mean, Ken Thompson says Doug's the smartest person he ever met. So this is where we're multiple levels above me at this point. wanted to do. I mean, Ken Thompson says Doug's the smartest person he ever met. We're multiple levels above me at this point. But Doug was extremely good at assessing, experimenting with, criticizing other people's work in a very constructive way. So he was a secondary or the outside reader on my PhD thesis, and he greatly
3:05improved my writing and the content of the thesis. And he continued to do that essentially for his whole life. He's still doing it. And he contributed a bunch of useful software, his own Unix sort program, dug Unix diff program, compares two files,, a bunch of things of that sort. He did language design and development of his own. He wrote one of the very first PL1 compilers. He invented the idea of macros. And it's just on and on and on and on. And he was also the department head who sort of had Ken Thompson in his department. Now, Doug wouldn't tell Ken what to do, obviously, but appreciated the work and was an incredibly effective technical critic of that kind of work. So, you know, gee, wouldn't it be nice if, or you thought about it that way, or just this sucks, whatever, to make stuff good.
4:04And that's a role that he played for the entire time that he was at Bell Labs. I first met him in 67, I guess. And he was until he retired, probably in the early to mid nineties, something like that. This, this reminds me when you mentioned department head somewhere in my research, it might've been Hamming. There was someone that you worked with who was a head of the department with no reports. have been Hamming. There was someone that you worked with who was a head of the department with no reports. That's Hamming. Yeah. Yeah. I never understood that when I first met Dick Hamming, you know, he was a department head. You could tell because he had carpet on his floor. I guess he showed up in the phone book that way too. But, and I couldn't figure out, you know,
4:45because I had this naive view that, you know, there was status associated with being a department head and it was totally wrong. But he had worked very hard to get himself a department head so that he had whatever status or clout or whatever went with it for useful purposes, but no people reporting to him. And so I think that worked out very well. Because in any organization, if you're not at the right level, you may get ignored. And so it was harder, presumably, for something, for people to ignore our department head than an ordinary MTS. So he got the clout without any of the work of... Without the dog work. Yeah, right, administering.ing i mean he'd put in his dues because he he came to the labs i think in 46 and did a lot of early stuff with computing
5:33as one of the very first people to realize that computer actual use of computers was going to be a very important part of all kinds of research in the future. And he made this prediction that, that at some point more than half of the research work would be done by computing, not in physical labs. And of course they laughed at him.