Ken Thompson built a Unix system in three weeks

Transcript

Transcribed by machine (Whisper) from the episode’s audio, so a word may be off here and there.

1. 28:00

   Was there anyone that, I guess, or any story of someone who kind of impressed you the most, or 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, unparalleled. And the story is the other first version of Unix, where he's got this little old PDP-7, which is an obsolete machine, has something like 8K 18-bit words.

2. 28:33

   So it's, you know, a tiny little machine. And he's been fooling around with something to drive the disk 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. And his wife takes their young son off to California for three weeks. And he thinks, hmm, I could do something here. And so in three weeks, he builds himself an editor, an assembler, and an operating system, and there you have it.

3. 29:00

   By himself? Yeah. Oh, yeah, absolutely. When I used to write something, you'd go to Stack Overflow or you kind of look up how to write the code and then you write it. 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. nine and uh so he's probably writing the code on in assembly language bear in mind not not any high level language and 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.

4. 29:51

   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. You know, 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, you know, ML kind of thing. And so he set me to working on something, and I almost instantaneously went somewhere else.

5. 30:21

   And 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 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.

6. 30:57

   So he was a secondary or the outside reader on my PhD thesis, and he greatly improved 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, Doug, Unix diff program, compares two files, Doug, a bunch of things of that sort. He did language design and development of his own.

7. 31:27

   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 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 said about it that way, or, you know, geez, this sucks, whatever.

8. 32:00

   to make stuff good. And 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 Caroli to mid-90s, something like that. This reminds me, when you mentioned department head, somewhere in my research, it might 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 hemming and you know he was a department head um you could tell because he had carpet on his floor i guess he showed up in the phone book that way too but um and i couldn't figure out you know because i had this naive view that you know there was status associated with being a department head and it was totally wrong but um but he had worked very hard to get himself a department

9. 32:53

   head so he had whatever status or clout or whatever went with it for useful purposes but no people reporting to him and and so i think that worked out very well because you know 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 the dog work yeah right administering i mean he he'd put in his dues is because he came to the labs, I think, in 46 and did a lot of early stuff with computing.

10. 33:30

    He was 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 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.