I did fall in with a group called the Tech Model Railroad Club. I reallythought that was great. Relay logic was right up my alley. They had arailroad layout completely done with relay logic and stepping switches.Through that, I got slightly in touch with the people at RLE—Research Labof Electronics. This was still in the era where we spent all of our time in thebasement of Building 26 typing up punch cards on the keypunch, which wewould then hand to the shaman, who would give us listings back the nextday. Then I started hanging out at Project MAC. Basically, when I wassupposed to have been doing lots of math lessons, I discovered I wasspending more and more time hanging out in the computer places.

And after RLE, you went over to Tech Square. I met people like RichardGreenblatt and Bill Gosper. But I was just drifting through that world; Idon’t think I was doing much programming. Like I remember how I gotinvolved with Project MAC: I was really taken by Spacewar! on the PDP-1.But I didn’t approach it as a hacker or a programmer—“Let me see thesource code. How did you do that?” I just thought the game was the neatestthing. I was just a gamer at that point, as opposed to a programmer, and Ihad heard that the guys over at Project MAC had done a super version ofSpacewar!, that they had fancy consoles, and they had a spare PDP, so Iwandered up there. So I got to meet Peter Samson in his great failedattempt to solve the New York City subway system, to ride the wholesystem on one ticket as fast as possible.

I was probably a sophomore, deeply entrenched in the usual sophomorethings, watching all of these guys who were clearly adept and clearly knewwhat they were doing. I was writing little programs to solve a maze. Thefrog had to hop from lily pad to lily pad and get out of the middle of thepond. I remember writing that program and helping other students from mydorm get theirs working. But that’s where I was at. I had no clue whathappened after I handed my deck in.

As I look back, I would say that at that point, I was learning the craft ofprogramming. I could sort of make computers do what I wanted. But thelight hadn’t gone off. I hadn’t internalized it; I didn’t really understand whatwas happening. It was all a little bit magical and strange. And that was how Iwas drifting through college. The thing that really made me a programmerwas going to work at BBN.

One of the guys I had met at college, who had graduated and worked atBBN said, “Come out here.” He took me out one night in the middle of thenight because BBN was a 24-hour-a-day, 7-day-a-week weird place. It wassort of an extension of the MIT labs. People could come and go at all hours.And he was part of the night crew. So we went out one evening. It was alltoo mysterious and marvelous to understand; I just had no clue what he wasshowing me. Not long after that, he suggested that they hire me. And sothey had me out, interviewed me, and hired me.

Seibel: This was when you were three years into MIT?

Cosell: Correct. In September of my junior year they hired me part-time. Ibelieve I made it until October before I dropped out and went to work fulltimeat BBN.

In retrospect, I wasn’t very good. I had seen a PDP-1 but I had no idea howto program one. I didn’t know anything about time-sharing. That, of course,was not surprising, since there were probably maybe 50 people on theplanet who knew what time-sharing was.

But BBN was working on a project with Massachusetts General Hospital toexperiment with automating hospitals and I got brought onto that project. Istarted out as an application programmer because that was all I was goodfor. I think I spent about three weeks as an application programmer. Iquickly became a systems programmer, working on the libraries that theywere using. And not long after that, the two systems gurus, the guys thathad written much of that PDP-1 time-sharing system, took me under theirwing and designated me their heir apparent. That winter they both left BBNto go back to grad school. By January I was the czar of the PDP-1 timesharingsystem—I was responsible for the whole mess.

But in that little interval, a whole series of lightbulbs lit up. All of a sudden, Iunderstood time-sharing. I understood real-time systems. Once Iunderstood it, I absorbed the time-sharing system. And everything’s beendownhill for me after that.

The project was quite ambitious for its time. The idea was that there wouldbe a Model 33 Teletype—noisy and clunky and uppercase only—on eachward. There would be a Model 33 Teletype in each doctor’s office. Therewould be a Model 33 Teletype in the pharmacy. And there would be, Iguess, a Model 33 Teletype in the admissions office. And our little timesharingsystem was going to coordinate all of that.

When a patient got in, they would be assigned a bed. The doctor wouldschedule lab tests. At which point, the nurse’s Teletype would say, “Takethese samples. Put this number on it.” The lab would get a message saying,“Run these tests.” If the doctor prescribed something, the pharmacy wouldbe told and the cart would be ready.

It was amazing to have those little noisy, silly things on the wards. Havingthat level of professional dealing with these clunky things was really prettyoffensive, so there was a lot of resistance. But I was sort of immune to all ofthat, because I had gravitated off to the systems part of the world.

And I had decided it was really important that the system not stop. I don’tknow if they told me that or not, but I decided that we had to prove—I hadto prove—that time-sharing could work. That it was a good enough andsolid enough thing that you would consider running a hospital with it. Ithought about what happened if a patient needed medication and the systemcrashed? Or worse, the system lost the prescription and the patient nevergot dosed? Or the system juggled prescriptions and the nurses had actuallystarted trusting the system? So I started thinking the system should notcrash. This system should be good as Unix 30 years later.

But there was no real-time debugging. When the system crashed, basicallythe run light went out and that was it. You had control-panel switcheswhere you could read and write memory. The only way to debug the systemwas to say, “What was the system doing when it crashed?” You don’t get torun a program; you get to look at the table that kept track of what it wasdoing. So I got to look at memory, keeping track on pieces of graph paperwhat it was doing. And I got better at that.

In retrospect, I got scarily better at that. So they had me have a pager. Thiswas back in the era when pagers were sort of cool and only doctors hadthem. It was a big, clunky thing and all it would do is beep. No two-way. Nomessages. And it only worked in the Boston area, because its transmitterwas on top of the Prudential Center. But if I was within 50 miles of Boston,it worked.

And basically, I was a trained little robot: when my pager went beep, beep,beep, I called in to find out what the problem was. What was bizarre wasthat with no paper, in a parking lot, on a pay phone I could have themexamining octal locations, changing octal locations and then I would say,“OK, put this address in and hit run,” and the system would come back up. Idon’t know how the hell I managed to do that. But I could do those kinds ofthings. I took care of the time-sharing system for probably a good two orthree years.

Seibel: At this point, you had presumably written a lot of the code despitehaving originally inherited the system.

Cosell: Yeah. The operating system was not done when I got it. It wasbuggy and there were pieces of it that were not finished when Steve Weissand Bob Morgan went off to grad school. I did something that they hadn’tdone—it was one of the things that I got known for around BBN, which is, Imade things work.