An interview with Arthur Luehrmann

 

 

Kevin Bunch: First off, I saw that your background was in physics and natural science.

Arthur Luehrmann: That’s correct.

Kevin: How did you get involved with the Dartmouth computer program in the first place?

Arthur: Well, I got involved in computers as a graduate student at the University of Chicago. I was doing a thesis that involved a lot of computation. It was basically a cataloging thesis, all the possible formations that crystals could grow in. It turned out, the best way to do it was to write a general-purpose program that would explore different crystal symmetries and print out all the relevant numbers that scientists would use, who was investigating those structures. This was in the days of germanium, and solid-state devices, and all that.

There was a great deal of interest in understand basically the electronics of crystal structures. To do that, you had to know the structure of the crystal. My work was essentially library work, creating a library of numbers for the various symmetries of each kind of a crystal. That got me involved in computers.

While I was doing that, an opportunity came up to go to Bell Labs and make a movie on their computer, just to explore what you could do using computers to generate graphics, and those graphics were coming moving. I went there and spent a week, and found out how to use the tools that they had, and came back with a little one or two-minute movie of a geometrical structure rotating. That was fine.

Then I got a job at Dartmouth. Dartmouth had just gotten its time-sharing system, which was put together largely by students with a few faculty supervisors. John Kemeny, who went on to become the president of Dartmouth a few years later, led a team of a dozen or so really interested students, and built the time-sharing system. Was one of the first ones ever. MIT had a time-sharing system it had built, but it was primarily for researchers.

Kemeny’s notion was computers are for everybody. Let’s build a system with terminals all over the campus, so students can use the computers, and use them in learning and just in fun. That happened. We ended up with, I think, originally about 30 terminals around the campus. A few were hardwired into various telephone lines, but we also had acoustic couplers. We had a teletype machine at home, for example, that had an acoustic coupler so I could log in remotely.

Of course, the teletype machines was 10 characters per second, check, check, check, check, not too exciting for gameplay, but nevertheless, some textual games. In fact, John Kemeny, who went on to be the president, wrote his own football game. It was one player after another. He knew all about logic and probability, so he built in the probability outcome of each kind of play, and so he did that.

He even had a moment in the game, which stops and then it announced “dog on field”-

[laughter]

Arthur: -which often happened at Dartmouth football games because there were many dog lovers there, and the field was pretty open. It was very teletype oriented. It was, you made your play, you saw the outcome, you made your next play, and so forth. The odds were reasonable coming from Kemeny who knew statistics. That was one.

I was instrumental in getting graphics into the system. We were able to get plotting devices that could connect to the teletype machine. Even at those low data rates, it was okay. [chuckles] The plotter could move, [gibberish] around to draw whatever, I used it in teaching physics because there were a few mathematical problems that you can solve in motion in mechanics dynamics, very few close forms and solutions. You can look at pendulum swinging. You can look at a ball bouncing. You can look at a motion on an air track. That’s pretty much it.

With graphics and very simple programming that I could teach my kids, we could calculate orbits around the earth. We could calculate orbits that included another body, say, looping around the moon and coming back. You could see it right there on a pen plotter drawing it out. Then we managed to get, from Tektronix, a terminal that had a- what was it called? It was a storage screen that is the cathode ray would write on the screen, but the writing would be remembered until you flushed it.

You could do the same things with the paper, the pen and ink plotter, you could do it on the screen there. I developed some games there that were graphic. One of them was, it would draw a random mountain, and on each side, a position varying in height. The game was to shoot over the mountain and lob the other guy. We call it Potshot.

Kevin: I’ve heard of Potshot. [laughs]

Arthur: Yes. That’s how that began. That was fun because it was graphics. It was not just text of a football game, but you could see the actual results. We had enough plotting devices at that time that could play either on this storage display screen, or on a pen and ink plotter. That was fun. My son, who was about 12 at the time, would take bets. He’d go over and con people just playing it.

Kevin: That’s great.

Arthur: He discovered that I hadn’t ever tested whether the shot was over the mountain. He would shoot through it straight at you at a very high velocity, so gravity is not involved, and shoot the other guy down with one blast.

Kevin: That’s really funny.

Arthur: Anyway, that’s how I got into the gaming side. Well, it was also teaching physics and raising money for various computer projects on the campus.

Kevin: What were your thoughts on Dartmouth BASIC, because my understanding is that’s what a lot of the time-sharing system was programmed in?

Arthur: Dartmouth invented BASIC. It was serviceable because– Well, I was skilled at FORTRAN because that’s what I did in my thesis, but FORTRAN was a pain in the tush. It was not interactive. You would put a deck of cards in behind a wall. You came back the next day and you got your output. It was mostly syntax errors, mostly what are called Hollerith display errors. Then you would wait 10 hours and put them back in.

BASIC was interactive, and it was a very simple syntax. It was easy to teach beginners the rules. It had both numeric type and a string type, and that was it. Nothing more complicated. No complex numbers. Nothing like that. It would take not more than half an hour to teach beginners.

The introductory math course taught everybody on campus how to program in BASIC. Staff and faculty, of course, were behind the curve, but they picked up. They did more and more interesting things, including building databases of various kinds of art, and historical databases, and so forth. It was good.

There were people who were critical of it because of its limitations. It could not do complex numbers. It handled strings reasonably well as a data type. A lot of scientific research was done on those computers at the time. It was an adequate language. It spread line crazy. Every time-sharing system that was developed commercially had BASIC as its programming language. Controlled data had a BASIC. I’ve forgotten who all the players were back then. You know who learned? Bill Gates learned to use computers on a terminal connected to a copy of the Dartmouth Time Sharing System.

Kevin: Wow.

Arthur: When he was about 10th, 11th, 12th grade, his mommy got a terminal at home for him to have access to. That was his first experience with programming. Naturally, that’s the language he put on the first microcomputers that he was involved in designing.

Kevin: Lucky kid. [laughs]

Arthur: Lucky kid. He was [crosstalk]–

Kevin: Get his own timeshare. Oh, go ahead.

Arthur: No, that’s all. You go.

Kevin: I was going to ask, so when did you pick up BASIC? Was that shortly after you came to Dartmouth or–?

Arthur: Yes, within a week.

Kevin: Well, it was pretty quick. [chuckles]

Arthur: It was really easy.

Kevin: What was your impression of John Kemeny, and I think Thomas Kurtz was the other person who worked on this?

Arthur: Yes, Tom and John were the leaders. The workers were students, half a dozen or a dozen students. They did major contributions. They had to figure out how to do the time share from scratch. They wrote all the code, debugged it all.

Kevin: Did you work with them directly at all while you were with [crosstalk]?

Arthur: No, I did not. I got to know them personally, but I did not work with them when they were really being developers. Software developers is what you would call them today. No, I didn’t work with them. I had some in my courses, I was teaching physics. Many of them were Physics students so I got to know them personally.

Kevin: What made you enthusiastic about the computers at Dartmouth, and then encouraging students to use it more? I guess [crosstalk]–

Arthur: I was approaching it as a physics product. I realized I could teach physics far better and much more of physics with computer models than I could use traditional calculus. There are very few problems that can be solved at closed form in calculus, very few physics problems. Falling bodies, you can do. Some circular motion, you can do. Sinusoidal oscillations, a pendulum, you can do. An arbitrary force acting at a distance creating bizarre orbits, you can’t solve those, but you can simulate them.

You can teach people in programs no longer than 10 lines how to calculate step by step given the forces what the acceleration will be, from that, what the velocity is going to be, and from that, what the position is going to be, then draw the position out. That’s what really hooked me.

Kevin: Do you remember the circumstances around, you mentioned the Tektronix plotter, and then the display. Do you remember the circumstances around those arriving at the university?

Arthur: Yes. Tektronix’s had reps who would come out because they were selling lab equipment for the science courses and the medical school. I encountered one and showed him what we were doing. He got interested. The next time I saw him, he had a terminal that could do graphics.

There are two kinds of graphics on terminals. One kind is a refresh type. It generates each picture, and that’s gone, and the next picture comes up. Then you get motion like you do in the movies. but the Tektronix terminal had a memory screen. It would write. It would put it out on the screen. It would stay there. Draw a line, it would stay there. You’d plot motion much as you would on a pen and ink platter and do all of the things that I was doing already, but in a much more pleasant environment.

You didn’t put ink in the pens, and you didn’t have to worry about that. It just drew. When you were done, you could just erase the whole thing. That’s how we got involved in that.

Kevin: That was around ’68, ’69?

Arthur: Probably, yes. I think so. Probably yes.

Kevin: How did having that display impact your work at the university?

Arthur: Not directly. It affected mostly my teaching. I could really teach the introductory mechanics course in a way that I never could have before. As I said, there were just a few problems that are solvable in closed form in physics, and you can’t do anything else. The excitement that students got from seeing that they could send a projectile around the moon.

One of the games I made was one where you’re in a stable orbit around the earth. There are two of you, and it’s Potshot. Once again, you’re shooting at the other guy, but subject to the real forces of being in orbit, which is almost stable, except you’re moving around a lot, and surprising things happened.

It turns out that the way to shoot the guy behind you was shoot ahead. The reason for that is the projector was going faster than you are. Doesn’t want to be in that orbit, wants to go to a higher orbit, then it slows down and comes behind. The other guy and gets in the rear. Kids thought that was pretty cool.

Kevin: It is pretty cool.

Arthur: We could do things like that.

Kevin: Do you remember what that one was called?

Arthur: It was Potshot still, but it was Potshot up in the orbit.

Kevin: Oh, okay.

Arthur: I don’t think we gave it a name.

Kevin: All right. What interested you about these demonstration and game programs?

Arthur: Well, I was approaching it more from a physicist’s point of view. There were things I could teach that I couldn’t before. There was no way we could go through all the formalities, but being able to– What can I say? You need the calculus as Newton did to be able to understand motion, but very few problems are soluble in closed form. As I said, the pendulum is soluble. The falling body is soluble.

The really exciting part for Newton was the motion of the planets. He was able to figure it all out, but did not actually show how to plot the motion of a planet or any object in a gravitational field. You could prove some things about it. The ratio of, let’s see, the planetary distances and their orbital times could be worked out, but actual motion, no.

Actual motion gets exciting when the space program comes on because they have to actually do calculations for moving objects in orbit. It’s the same old stuff. This is the same old stuff we were doing with kids, but suddenly it was on TV.

Kevin: [chuckles] What sort of exposure did you have to the demos and these little games and such? You mentioned that you wrote a little graphical program at Bell Labs. Were there any other things before this?

Arthur: No, we finally did get a PDP-9 computer with a good graphical display. Then you could play- was it called Star Wars? A motion game where we were shooting each other in space. Space Wars.

Kevin: Spacewar, I think.

Arthur: I think so, yes. Of course, that was a one-user system. It was not time sharing. You had to be in the room with the computer and the display. A lot of kids, especially the programmer types, got very involved in using the PDP-9 for graphics.

We had a lot of word games because the teletype machine was basically a character machine. As I mentioned, the football game was essentially a word game. You put in your play, and it did a little statistics and told you the outcome. I finally did a graphical version of that so you could see it on the field, but it was really John Kemeny’s invention. That was kind of fun.

There was a game, it was like 20 questions. It started out with, I think, one question. That’s right, it was asking you questions. It would ask a question. If you gave the right answer, it would ask the next question. If it got to the end and it was out, then it said, “Congratulations.” Then it said, “Name something else whatever category it was.” Fruit, “Name another fruit.” “Name the fruit you were thinking.” Then, “What question would you ask that has a yes or no answer about this fruit?” It would gather that. After a few days, it was a very long string of interrogations.

Kevin: [chuckles]

Arthur: It just grew up by itself. I thought that was pretty terrific.

Kevin: You said you did a graphical version of the football game. Was it still played the same way? You type in what you do–?

Arthur: Yes, exactly. It was non-dynamic. It was just play by play. It would draw the motion down in the field. If it was a pass play. It would simulate a pass, but it was totally non-dynamic. It was suitable for time sharing-

Kevin: [laughs]

Arthur: -because that’s all we had.

Kevin: I heard about a game that you worked on called Animal. I don’t know if you remember anything about that.

Arthur: Maybe that’s the one I’m talking about. What do you know about it? Remind me.

Kevin: Not too much off the top of my head.

Arthur: No, I think that’s the game, Animal.

Kevin: Oh, [crosstalk]–

Arthur: It starts out with no information and then every time it gets stumped, it asks you what your animal was. Then it says, “What question would you ask?”

Kevin: Got you.

Arthur: It would just grow. Well, one thing we had to do was invent a filth filter. You pick up an awful lot of literally crap, so we had to develop a filter for capturing all that. The trick was not responding, not saying I got you. Just passing it by and adding it to your collection.

Kevin: Oh, that’s funny. With enough college students there, you would need it.

Arthur: Oh, yes.

[laughter]

Arthur: It was in a way, very primitive in a way, but also very mind-expanding. We had limited resources, but it was amazing what we could accomplish.

Kevin: Do you remember about when you worked on these games? Animal, Potshot, anything else?

Arthur: I’m not too clear on that. [silence] Martha’s in the other room. Martha, when did we go from Chicago to Dartmouth?

Martha: ’65?

Arthur: ’65. I was there 12 years. ’65 till ’77. It was during that period, basically, more towards the beginning, first half than the second half. I did some games after that, but I got involved in campus-wide projects mostly involving computer applications, but in other departments.

I left there and went to UC Berkeley into the Lawrence Hall of Science, which had a small time-sharing system at the time, and developed some further stuff there. Apple Computer was just making computers. We negotiated with Steve Jobs directly to have him give us eight Apple IIs. We promised what we’d do is we had outreach programs, kids coming in. We would also go out to schools and do stuff. I was thinking, “Let’s bring our computer activities out to the schools.”

We built portable tabletops with wheels, and we had a van and we mounted Apple IIs on the tabletops. We would drive out to schools and unload, wheel them down from the van, and set up a class in the school’s only environment. That was great because it involved teachers. They could see the excitement that the kids had. Whereas when the kids came to us in Berkeley, the teachers weren’t there. They didn’t see how excited the kids were.

Kevin: [chuckles] [crosstalk]–

Arthur: I did that for a while.

Kevin: Well, I do want to talk about that for sure. Jumping back a little bit, what other programs were you working on like games at Dartmouth or any demos?

Arthur: I don’t remember.

Arthur: Yes. I remember Animal and the filth filtering requirement, and of course, all of those physics’ exercises, playing games in orbit. That was really more than just a game. Game of Life, Martha says. Remind me how that goes.

Arthur: That was a video-type game as I recall, Game of Life.

Kevin: Is that the one where you start some little life forms and then they just grow?

Arthur: Yes. You got more forms and so forth. That was around. I didn’t, do that. I may have implemented it, but it was not original.

Kelvin: Do you know if Tektronix’s used any of the demonstration programs from the Dartmouth time-sharing system?

Arthur: Oh, yes, when they were selling that terminal, that CRT with the memory terminal. In fact, I appeared in an ad with the terminal, then the terminal on displaying something that I had written for it. It was a select ad. I’ve forgotten. It was in some sort of a magazine or journal that probably scientists would look at because there was probably the big market for a storage display terminal. Text display on CRTs was really a business application. Yes, somewhere in my files, I have a copy of that.

Kelvin: What happened to any of these programs? Do you know?

Arthur: Oh, I don’t know. The Dartmouth system grew and grew and grew. It started with a little GE computer that can handle about 15 terminals or so. The group that the faculty group that developed it went to the NSF and got big funding for a big CPU from GE. That could support maybe 100 terminals, the first iteration. That became the modus operandi.

There was a group of people involved in the original development who went on to form a company to try to sell a service on a machine like that. That was moderately successful. The microcomputers really took over and with every– when anybody could have an Apple too, suddenly the excitement wasn’t what it used to.

Kelvin: Did you or anyone that you were in your circles subscribe to any of the computer enthusiast magazines of the time like People’s Computer Club?

Arthur: Not People’s Computer Club, but I think there were some others. I followed that with interest. I imagine many students who got savvy about computers suddenly saw the possibilities beyond what they were experiencing at Dartmouth, and went on to become involved in those. I wasn’t personally involved.

Kelvin: I wanted a bit about the COMPUTe program that you were [crosstalk]–

Arthur: That was a project funded by the National Science Foundation. The idea was to explore ways different fields could make use of computers, mainly in their teaching because Dartmouth was primarily a teaching institution. The math department, the psychology department, whole bunch of different people came together to discover and explore the ways that they could involve computing in the courses they were teaching to a student.

Kelvin: Great. How did you get involved in that particular program?

Arthur: I wrote the grant proposal with a colleague. I had a friend in the math department. We wrote a proposal to NSF.

Kelvin: Centrally involved. [chuckles]

Arthur: Yes very. At that time, there was an effort by the National Science Foundation to explore the uses of computers in education. They saw what was going on in Dartmouth and one or two other places, and were interested in spreading the gospel. They held conferences around the country and paid people to come and share what they were learning, what they were doing with each other. It was a big operation.

Kelvin: Did you ever–? Oh, go ahead.

Arthur: I was often to speak at those conferences.

Kelvin: That answered my question. [laughs]

Arthur: I probably have on a shelf somewhere some of the talks that I gave. That’s old history.

Kelvin: Oh, those would be cool to see, I’ll tell you what [laughs]. What brought you to Berkeley from Dartmouth?

Arthur: I ran out of things to do at Dartmouth. I didn’t have a department at that time. I was acting more or less as an independent agent, fomenting all kinds of computer activities in various different departments. I got an offer from the Lawrence Hall of Science at UC Berkeley to come out and get involved in the program. They had begun of teaching kids to use computers using their time-sharing system. I did that for a while.

It turns out I was a terrible manager. I had a good second. She he pretty much ran the show, but after three years I had to do something else. It turned out, an old friend of mine [Herbert Peckham], another physics teacher out here in California at a Community College, and I renewed our friendship. He’d been writing books for McGraw Hill to teach essentially the BASIC language on a variety of microcomputers. The market was being flooded at that point by different kinds, the Commodore PET, and just various ones.

He was writing for specific computers, introductions to programming in BASIC. He said, “Why don’t we do a book together?” I said yes. At that point, Pascal was coming along as a very interesting language. I didn’t know anything about it, but I thought that’s a great time to write a book. You’re learning and you know what the learners need to have, so we did. Apple bought out of them, and packaged it with the software. That’s how we started in the different career of becoming book publishers and authors.

My wife were, at that point, she got her MBA at Dartmouth while we were there and went to work for a company in San Francisco. After three years, she was ready to move on, and she joined the company. We were a partnership with three. We developed at least a dozen different introductions to programming for different computers. Each one are only slightly different from the other just because there are slight differences, but there were customized to that.

We got involved with Apple. They were developing a new version of BASIC. It was gorgeous. It was so modern. It was so structured. It was like Pascal in that sense of a structured programming language. Jobs killed the project. We were down working at Apple. We had offices there, so we could talk to the programmer who was writing this. That was great. We could just walk down the hall and say, “Hey, Don, how about this? Maybe do this. Instead of that.” He was very receptive.

I was particularly keen on getting graphics into this version. He was after to that too. We had offices right down from Steve. One day, he came to me. He said, “Well, we got bad news. We’re killing your project.” I said, “Why? This is beautiful. Don is doing such a great job. It’s the best version of BASIC there is. It’s got a lot of Pascal-like features. It’s got control structures and all that good stuff.” He hemmed it hard.

It turns out that the Apple II at that point was the monument. They were developing this mainly for the next machine. Our friend, Billy Boy [Gates] from Seattle said to Steve, “Well, I don’t think you should bring out this new version. You’ve got BASIC programming on your Apple II. Why do you need that?” Steve knew enough to say, “This is different. This is a great language.”

Our guy said, “Well, I’ll tell you what. If you go ahead with this version of BASIC, I’m not going to renew your license for Microsoft BASIC, which is what they called it at Applesoft, is Microsoft BASIC.” Well, the money, the cash cow, was the Apple II. That’s what they were selling. This future machine was- who knows? Might be great. Might not. Steven essentially kowtowed and said, “Okay, cancel the project.” We were already in proof for the book that we were writing to go with it.

Kevin: It was almost done.

Arthur: The process had run, and we were just looking at proof copy before it went to print. Of course, that never happened because the project was canceled.

Kevin: Very interesting development.

Arthur: We were very unhappy about it, but understood this situation Steve was in.

Kevin: What was the developer’s name for that? You said, Don?

Arthur: Don. Yes. Martha, what was Don’s last name?

Martha: Denman.

Arthur: Denman. Don Denman. Somewhere in my stuff, I have the page proofs for the book. Then we went on. We did some more things. We did more books about the applications, because most people were buying computers, not to program in BASIC, but to do word processing, databases and spreadsheets we did books on that.

Our last work was a book for IBM. They finally wised up that they needed a desktop computer for kids. They made a big deal out of this new development. They hired us to write the book that would be packaged with the computer. Well, that’s my retirement that did that. With my partner and Martha, there are lots of stories to tell about that.

The basic thing is that their computer for kids was essentially the desktop computer repackaged that they were selling to businesses but kind of prettied up a little to make it look like it was for kids. We wrote the book. Fortunately, they did bring out the computer, and they did pay us off, but it was a total disaster. Our theory is that those sinkholes in Florida, they’re full of PCjrs.

Kevin: [laughs] I was going to ask, was this the PCjr?

Arthur: Oh, yes. Absolutely.

Kevin: It was a bit of a [crosstalk]–

Arthur: They were so proud of it. When we got the prototype because you can’t write a book about a computer without computer, these two guys in blue suits came out. They had a package and they had a handcuff between one of them and the package. They required us to rent a space where you could work that had no windows. This was really top secret [chuckles].

Anyway, we did the job and we got the book published, and we ended that happy. That was the PCjr. That was the end. We didn’t do anymore. I didn’t do anything more beyond that.

Kevin: Did you have any interactions with the Berkeley area, Silicon Valley, computer club-type folks?

Arthur: Oh, I went to all the computer fairs starting the day I got there. That’s where I met Steve Jobs the first time, and got him interested in doing the project. I was telling him about him putting computers on real desktops and taking them out to schools. He remained a fan, in a way. He’s a tough edge person, but I liked him a lot. There was that.

There were computer fairs, and then the education establishment in California started having annual meetings where teachers shared what they were doing with computers. That went national. They were both in California and Oregon, Texas. I did a lot of travel at that time, giving talks and boosting stuff. When I turned commercial, I also sat in a booth selling books [chuckles].

Kevin: [laughs] Did you ever run into any of the BSD Unix folks there at Berkeley? I think it was Ken Arnold and Bill Joy were their names.

Arthur: Never more than casually. No. No. I did have some time at Xerox Park. Alan Kay was the top engineer at Xerox Park and he was keen on developing an interactive terminal for Xerox to do– He could see the way things were going. He had great ideas of what an ideal terminal or desktop computer should look like. The problem was that from Xerox’s management point, it wasn’t their business. They was the copy machine business.

They let the guys in Xerox Park play, but they never realized that they had a great product there. Now, who did realize, of course, was Steve jobs because paid visits there. He looked at it and said, “I got to have that mouse thing. That’s key.” He got the benefit of what Xerox Park was doing. Alan Kay was a brilliant guy. It was a pleasure to know him and interact with him.

Kevin: What have you gotten up to after the whole PCjr thing?

Arthur: That was it. That paid enough for us to retire.

Kevin: That’s great.