Jim Yurchenco and Rickson Sun joined IDEO (or Hovey-Kelley, as it was called in its early years) not long after its founding. Like the company's founders and many other early employees (and indeed, many of the designers who worked for Apple in its early years), they graduated from Stanford: Sun studied with David Kelley in the Product Design Program, while Yurchenco received an MFA. Both worked on the Apple mouse project with Jim Sachs, Douglas Dayton, Dean Hovey, and David Kelley: Sun contributed to the electrical design, while Yurchenco was responsible for the design of the interior structure that held the ball, optical sensors, and electronics-- what later came to be called the "ribcage."
The interview was conducted on 26 April 2000 in a conference room in IDEO's main office in Palo Alto. The original tape has too much background noise to be published online as an audio file.
NOTE: This version of the transcript has not yet been reviewed and corrected by Yurchenco and Sun.
Yurchenco: Engelbart of course deserves credit for the concept of a hand-held pointing device. The credit our company gets is a bit misplaced: nobody should assume we invented the mouse. What we did was take a laboratory concept and turn it into a manufacturable product at a reasonable price. It's an important step: commercialization is really the "D" part of R&D, which Xerox Parc wasn't doing, and SRI wasn't doing at that time. But the intellectual idea of the mouse, certainly we do not deserve any credit for.
Pang: When you started your work, you had seen the Xerox mouse, correct? [Nods] Had you seen the Engelbart mouse, the great big one?
Yurchenco: The only mouse I had seen was the Xerox PARC mouse, which had commutators for doing the encoding, a small ball, and an elaborate gimbaling system.
Yurchenco: It was immediately obvious that this was not a viable product, and you couldn't build them in any quantity. Using optical electrical encoders is something that 99% of mice in the world still do today.
Sun: The forces [in the mouse] are very low that are available to move an encoder to pick up information, so anything with little wires rubbing against spinning disks was going to take more force out of the system than interrupting light beams would. So the early direction was to use light beams rather than rubbing insulators and contacts past a little contacting finger.
Yurchenco: The people at Hovey-Kelley who were involved, of course, were to begin with, myself and Sachs, and Dean Hovey, who was one of the founders of Hovey-Kelley and David's partner. Jim had responsibility for electrical engineering, and Dean and I had responsibility for product design and mechanical engineering.
The first things were did were to go out and see what ideas we could steal, which is how engineers work-- why reinvent the wheel?-- and one of the things we came up with was a trackball module, a very large trackball used in Atari game machines. We looked at it, and what they were doing was interrupting beams with slotted wheels-- a different orientation, and everything was at a much larger scale, and of course the ball was supported by the structure and was depending just on gravity, but it sure seemed like a real promising approach....
So very quickly we built some prototypes, scaling it down to a size to at least [gets clear prototype]-- I don't know what generation this was find out, can be made as something that can be hand-held
Pang: Now, this does not have a button--
Yurchenco: No, because the button was not a real issue: it was just a switch with a cosmetic cover, so there's no real technology involved there at all. The technology was here on the inside, and there were a couple things I think were key that we brought to the table.
Sun: The first was going in the direction of optical encoding. It was the answer then, and as you can see, it's still the way mice are made. Now, the optical encoding in those days was more complex, because you had to use off-the-shelf phototransistors and off-the-shelf LEDs, and everything now is custom to mice, and they're packaged in dual packages, the tolerances are better, and you get more dots per inch and fewer parts, but those are just incremental improvements.
The second things was allowing the ball to float. In all the mice before-- in the Xerox PARC mice, Engelbart's mouse didn't even house a ball, but two encoder disks-- you're actually forcing the ball on the table, and the Xerox PARC mouse had a gimbal on top of it that tried to force the ball down. We very quickly realized that you didn't need to do that, that you could get rid of all those parts that were fussy and tended to get dirty and so forth, and that gravity alone would suffice to allow you to do that.
The third innovation was coming up with an idler here [points to idler in ribcage], so the ball is actually suspended between two orthogonal shafts, and is pressed against those shafts by a little spring-loaded wheel of some kind. In this case it's a wire spring, and there are a lot of variations now, but every mouse you open now will have that third point of contact on the ball, and allow the ball to be forced against the shaft, so there's a little bit of friction between the ball surface and the shaft surface. So in terms of technology innovations, those were probably the key elements in developing this thing.
Pang: Now this [prototype] has two of these three, right?
Yurchenco: This doesn't have the idler; this was built before we realized the need for it. This was adjusted so you could try to push it [the ball] against these foam rubber rollers, but foam rubber rollers would never have the lifetime you need for a commercial product, and they take up the tolerance, so we knew we'd have to go with some kind of hard roller. After a while it became obvious that you'd need some kind of compliant member on this side [the side with the idler], since you couldn't have one over there [with the rollers]. And so that's how that evolved.
The other things we brought to it was the actual product design, which was miniaturizing and cost-reducing this thing, which first of all takes you into the world of injection molding, which is the lowest-cost way to make complex parts. Then it was a matter of basically squeezing the geometry down. That was a fun exercise, and that was primarily my responsibility, designing this [unrolls drawing]-- what came to be known as the ribcage. There were a whole bunch of little pieces I designed separately, in different sections, and then pieced together.
This was in the waning days before CAD took over the design world, when paper and pencil was still the operative mode. There were primitive CAD machines available at that time-- primitive by today's standards-- but they were relatively expensive and Hovey-Kelly design didn't have the wherwithal to buy them. So we were still operating in a paper and pencil world.
And so behind this drawing was a lot of chickenscratching on paper, and a lot of calculations in terms of spring forces and snap forces and so forth, just the-- I guess it's just the magic of visulaization in terms of how are things going to fit together in a 3D way.
Pang: Both Jim Sachs and Bill Lapson talked at some length about the Stanford program as having contributed important things to their approach to design, to their thinking about designing with an eye to manufacturing. I wondered if you could say about your background, and how you learned to visualize things?
Yurchenco: Well, I went to Stanford, but I got a Master's from the Fine Arts Department, I got an MFA in Sculpture. So actually I've never had an engineering course in my academic career. Of course, sculpture is partly visualization of objects and space and volumes, and my work tended more toward the technological end of things, particularly at Stanford I built a lot of interactive mechanisms and so forth. I knew a lot of people in the Stanford design program because I hung out in the product design shop. As soon as I got to campus I found about it and went down, and met Dave Beech, who ran it, and we've been friends ever since. I basically lived there. Of course, at the time the design division was attached to the shop, and that was where I met David Kelley, and quite a few other people in the program, but I never actually took any courses in the program.
Sun: I think what we benefited from-- Jim did it without thinking about it-- but a lot of engineers are used to sitting around calculating, and thinking about a solution to a problem. Jim's technique was very consistent with what the program was teaching, which was build it, touch it, feel it, and you're going to learn more from that than sitting around and thinking about it. Once in a while you have to do a couple calculations... but usually you can learn so much more from touching and feeling something.
That's really the point of view the program presented. We can talk about the specific courses, but it started with ME 101 and visualization, where they teach you how to imagine and use your mind's eye and do experiments in your head, but imagining things; then they tie it into the shop. Dave Beech was a critical part of it, actually quickly getting up and creating something that you could touch and taste and smell.
Yurchenco: Well it's not just that you have an object that you've created-- though that's an important part of the process-- but also in learning how you build those objects, you learn, what can I actually do in the real world. You can put all sorts of stuff on paper that you can't make. And by being exposed at least at some level to shop processes and shop technologies, you quickly realize that, "Boy, I can draw this thing, but I'm going to create living Hell for someone downstream who actually has to make it."
So one of the emphases is on manufacturability, and to some extent injection molding has different parameters associated with it: since you're only making the tool once you can get away with things that are extremely difficult. But still, even if you have these injection molded parts you have to be able to assemble these objects, and people have to be able to put these parts together.
So the whole awareness of the human being as part of this process of technology is one of the things that the Stanford program emphasizes. Technology doesn't just exist over in its corner there without some human context, whether it's the guy who's making the part, or the person who's assembling it, or the user of the product. I think it's one of the things that's really important that that program emphasizes.
Sun: I think that's absolutely right. Designing from human experience is very much the focus. I think the key thing is never forgetting the human, and always testing your idea against what the human involved can do. But the issue of making it is frequently ignored... and a large number of people we've met or interviewed learned in their schooling that it was okay to ignore that, because someone else would take care of that. I think that's a significant advantage that the Stanford program has, that all the engineers were asked to make stuff. It was part of the course and training.
Yurchenco: You think about your own experiences. Maybe you've worked on your car, and there's something you have to do on a regular basis that's almost impossible because some engineer didn't actually go beyond his drawing board, and go an build a little model, and say, "Can I get to that oil filer, or is that spark plug accessible?" And you start to wonder, this really isn't engineering. This is not-- it's something else, but it's not nothing to do with engineering, with good design.
Sun: I'm not sure if this word was used back at Stanford, but we use it here at IDEO, and that's "empathy": empathy for all the people who are going to be involved with the product. And so being able to take their points of view, empathizing not just with the person who makes the mold, but with the person who has to mold the part, but the person who has to take the flash off--we can by understanding the players and their points of view we can make a better product. All the people have to snap these parts together, we think, "How hard to they have to push to snap these parts together?" They have to do this all day and all night, will they, what's their lives going to be like? The people who have to put these in boxes, the people who have to write instruction manuals-- every point where a person touches this product is an opportunity for us to develop empathy for their point of view.
Yurchenco: And of course, in this phase of our careers, we were pretty naive about what could actually be done. [laughs] We didn't have any human factors people in our organization, there was no one to talk to, so we were talking to your peers, who have about as much experience as you do; but you have your own human experience, and at least you were coming from a point of view, of starting from the right place.
Pang: Now, the company itself was still rather young when the mouse--
Yurchenco: Oh yeah, this was 1980. I had joined in 1979, and Dean and Dave had started the company in the fall of 1978, so the company was a little over a year old at that point.
Pang: And how big was the company at this point? Fewer than 10 people?
Sun: I was number 10, and when I joined, most of this was done already, and Bill Lapson had just recently signed (?) and I was helping him think through how to make sure the product was going to be robust and reliable-- doing drop tests and wear tests, and that sort of thing.
Yurchenco: When we started on this there were probably five people, I would guess, five or six. There's some argument about who was actually an employee or not, and who gets counted: Dean's wife was worked part-time as a bookkeeper, so yes, she worked for the company, but is she included on the list or not? It's an angels dancing on the head of a pin kind of problem, but it was pretty small. I think Douglas Dayton was already there when you joined, right?
Sun: Yeah....
Pang: How did your relationship with Apple work? Did you seen them very often when you were working at this stage, did they have to approve things at regular points, or was there was more autonomy?
Yurchenco: There was a lot of autonomy. I can't remember very much review at all from Apple on this. I think what we eventually did was, we delivered prototypes, and if they worked they were happy, but the day-to-day, and the design decisions that were being made-- there was kind of a spec, but I can't remember ever seeing a fully written-out spec at that point. [Pang laughs] Although that's not so-- you laugh, but even today-- Apple was barely more than a startup at that point, and even today we do a lot of projects that don't have any specs, there's just lots of arm-waving and agreements at meetings, and then you argue later what you said, but writing specs takes too long in this industry, you gotta get too many people on board and make too many decisions with not enough data.
Sun: We have a philosophy around that as well. You can build a prototype, and show it to people, and get them to respond to you. Before you do that, they're telling you what they want: they say, "Well, can you build this and this and this for me." And you write that down on a piece of paper, and that's the beginning of the spec. You come back to them, and you show it to them, and they say, "That's what I asked for, but that's not what I want." That's because you can't sit there and visualize-- out of nothing-- the future.
Yurchenco: Most people can't.
Sun: You need to touch and feel something. You need a this, and a that, and you say, "Can I have this but not that," and people can start to put it together, and people can start to do that. The point I'm getting at is that rather than sitting around and writing specifications we'd rather build things and get these things in front of us, and have the interaction that way.
Yurchenco: Be that as it may, there are still some things you have to establish up front in terms of goals. [Holds up mouse] The resolution of the thing, because that drives a whole bunch of engineering. How many pulses per inch of travel this thing puts out, what the operating conditions are, will it fit in one hand or two hands, will it have one button or three buttons? The designer, me, sitting down here with a piece of paper, has to have a decision on these kinds of things, because it affects what I draw on the piece of paper. So there's always a tension between the approach of keeping things free and open and just sort of build things and showing them to people, and getting things nailed down so you can move ahead on the process.
Sun: Right, right. Clearly that resolution issue was-- there was a model set with the Xerox mouse already, so that gave us something to work with.... I worked at H-P on precision encoders. This was a low-precision encoder, and H-P was making a high-precision encoder, and transferring the technology involved understanding the limitations particularly of the molding, what the minimum window size was that we could reliably mold, and that would translate into resolution for the mouse.
Yurchenco: And of course we were pushing in the area of molding-- Our knowledge as a company at that point of molding processes and what could be done in tooling was pretty tiny. We knew a few basic rules, and we had a few guidebooks published by General Electric, with rules of thumb that after a while you learn don't mean anything anyway, so you're always wondering, what can I get away with? You're looking at other parts, other things that are out there, and saying, "Ooh, look at this. They did this, so maybe I could do this, too."
Pang: Was it clear that you had to go with injection molding for this, or were there--
Yurchenco: There were no other viable alternatives, in terms of effectiveness for the dollar. The cost of these parts is so low: basically you rent a machine for X dollars an hour, and it'll produce Y parts per hour, and the cost of materials is a dollar a pound or something, and you're dealing with grams of material per unit. It's accurate, it's reproducible, the tooling is relatively inexpensive. There are other processes used for high-volume production, but all of them have drawbacks compared to injection molding for this type of product, where you don't have really difficult mechanical environments for things to live in-- high temperature, high forces, radiation, so forth. For normal human environments this is a great process.
Sun: It was amazing that when we went over the resolution requirements, given the state of the art you were willing to push injection molding, to how small you were willing to mold those slots and encoders, and it worked out.
Yurchenco: [spreads out drawing] Rickson's talking about these little wheels that have slots that open and close in front of the LED and phototransistor, which are captured inside this device. How small a piece of steel can you accurately make? This was 20-some years ago, and injection molding has come a long way particularly in tooling, and one of the reasons that mice are cheaper is that you can do things in tooling that were extremely difficult to do in those days. Almost everything was machined in those days, and EDM work-- which was burning-- was relatively new and not widespread. And there certainly was no CNC machining, everything had to be made from drawings, there was no real connection to databases that you could use to compute cutter paths and so forth.
So there was a lot more human skill in making a tool like this in some ways than there is today. A lot of this is turned over to machines. The operators get a lot more metal cut per hour, and I don't want to denigrate the toolmakers. But the guy who made this (holds up model of ribcage) was a guy named Vic Renden, in a company called Mico-Molding over in Santa Clara, and this was a really magnificent piece of work that he did on this tool.
Sun: I don't think he's around any more, but he had some interesting stories, because it was a difficult part to mold. Apple pulled the tool from him, because they found someone who said they could make it for less, but it turned out they weren't able to make it. So they had to bring the tool back to Vic Renden.
Yurchenco: The bean counters sometimes take over and shoot themselves in the foot.
Sun: How long did it take you to come up with this?
Yurchenco: I don't know, I have no recall on what the timeline was on this.... I don't remember it taking an extraordinary period of time, maybe a couple weeks. I mean, it was fun; it was really fun. So the time kind of goes right by. This wasn't drudgery, this was a real kick.
Pang: How complex a project was this compared to some of the other work that Hovey-Kelley had done for Apple? I know there had been some work on the Apple III, for example-- Jim Sachs talked about working on a reset switch, for example--
Yurchenco: [laughs] That was-- he's poking at Kelley. Kelley actually did draw a key cap at one point, and it's become company legend, because it's just about the only thing he ever drew! David's an organizer, he's a social engineer.
But I would say that this was probably up there, in terms of the kinds of projects were doing at that time, because we had a lot more responsibility here in terms of, they basically handed it to us and said, "We need this, go do it." So we had to start from scratch, basically, figuring out what it was, and looking at what other example we could find, and taking it all the way through to looking for vendors and working with vendors to get the parts done. So in some ways it was the most involved project we had had up to that period time. Certainly as an application of technology, where we're integrating the electronics ourselves, it was. We didn't do the software, but Jim did the circuit drawings, and he actually did the boards, here's one of the prototype boards [holds up board], it says H-K right there on the corner.....
We were cheeky. A client would come in, and ask if we could do something, and we always said yes whether we had a clue or not, it was just, "Sure! We can do that!" Fortunately, at least from the Valley, the clients were were attracting those days knew even less than we did, so they were in no position to... see if we were telling the truth. And our attitude was, "Maybe we don't know this right now, but we can sure as Hell learn it, we're smart guys, we can go figure this out."
And it worked. We never hesitated, if we didn't know something we'd find someone and pick their brains or they'd consult for us, tell us what to do.
A lot of design I think just sort of-- I think really good design engineers, really good product designers, are just born this way. They're the kind of people who've tinkered all their lives, and they just know how things work. It's just part of their world view. And in a way you don't educate them, you just give them opportunities, give them more and more responsibility and more and more opportunities to do this stuff.
The technical tricks you learn, you pick up just by talking to people and looking at stuff and so forth. It's not something I'm convinced that engineering school has a lot of impact on. They'll teach you calculus and strength of materials and so for, and if you're a little drone designing a rivet for a 747, that's probably pretty important. But if you're in this business, where you get to design a whole product, I think you have to think broader than that. And for the people who are really successful, it's intrinsic. They just know it.
Pang: So how did Apple compare to some of the other clients you had, in terms of the amount of freedom you had to develop the product, the flexibility of the guidelines, the lack of tremendous precision in the spec-- what that standard in those days?
Sun: Um-hum [nods yes].
Yurchenco: At least the clients we had. All of our clients in those days tended to be smaller companies and start-ups, so they didn't have any infrastructure, and they didn't have any bureaucracy in place, yet. It wasn't until much later, when we were working with Fortune 500 companies, that that kind of stuff started to show up and we had to find ways of working around it.
The projects [in those days] tended to be very much relationship-based, and the success or failure would be dependent on, "Who was the person you worked with in that company?" Did you get along with them, did they understand your point of view, did you understand them, were they willing to let you run? The successful projects had people you could get along with and work with, and the ones that had people you couldn't get along with were failures. It really wasn't technology-related; it was a people thing.
Sun: The current conversation we've having today [in IDEO] is, how do we identify interesting projects to work on, when we have too many clients coming to us today with projects? Well, if we draw a matrix with "Big client/small client" [on one side] and "Big project/small project" [on the other], it turns out that small clients with big projects are much more interesting to work with than anyone else. With big companies there's overhead and the expectation to jump through structures that are somewhat artificial.
Yurchenco: One of the things, of course, with a lot of these companies we were working with was that these people were pretty close to our peers. They'd be within five to ten years of our age, and so most of them were coming from a somewhat similar mind-set: most of them hadn't spent time a huge amount of time in corporate America, and hadn't taken points of view that way. The suits, they tended to be over in Marketing, and they tended to be up in the executive suite, and you never really saw those guys; and so that helped, in general, and in terms of making it work well.
I mean, Bill Dresselhaus and Jerry Manock, they were our vintage, with reasonably similar backgrounds. So when you talked to them about ideas, and you talked to them about approaches, it wasn't alien to them: they didn't have some preconceived way that you had to do this, and that generally made things go pretty smoothly. A lot of this is only obvious in retrospect, looking back: at the time, it was all invisible, you were just doing things, and didn't know what was going on. And the Valley of course was in its infancy.
Pang: So the people on the Apple side who were responsible for making this work were Bill Dresselhaus, and Jerry Manock, and a couple other people?
Yurchenco: Yeah, Dresselhaus and Manock I think were pretty important, because we interfaced with them a lot. They're people I remember were really important , who stick out in my brain as people we really worked with.... Was there anybody else who really stands out.... There was a guy who was involved, his name was Lazily Zidek-- he was from H-P, and was one of the older guys, one of the wise, gray guys-- and he was a tooling engineer. And he had a few comments now and again. A guy named Bill Bull-- I think he was an H-P guy.
Sun: How often did Steve Jobs drop in?
Yurchenco: Jobs? He didn't poke around this project very much. I don't remember any specific interactions with him. I mean, I've got lots of stories about Jobs, but this is not one of them. In a way, that's one of the reasons I think it went well: he didn't poke around in it, he didn't micromanage everything. I mean, this wasn't on his radar, because this was Lisa, and Lisa was the enemy. So he was staying away from it.
I suspect that if he was deeply involved it wouldn't have gone well. [laughs] He would have other things he would have been concerned about, and some of them would have been valid, and some of them would have been completely in the way.
Pang: I had heard that he was involved in some of the oversight of these shapes [for the mouse], and they were presented to him and he passed judgment on them.
Yurchenco: I suspect for the Mac, yes, but for Lisa? I doubt it. I doubt he had much interest in that.
Sun: Almost all the development of the mouse mechanism was done for Lisa.
Yurchenco: And it was designed for a Lisa enclosure, and this was Jerry's work. I'm sure he showed it to Jobs, but I never got any feedback that it was a big deal, or that it went through three thousand iterations. It was just, Jerry had some sketches, laid 'em out, and I went back and said, "We need to change here and here and here so it'll fit," and we worked back and forth like that. But I don't recall it just being an endless drag out fight over, "This radius is not awesome," or whatever it had to be at that time. It was just done. I really think Jobs just didn't have us on his radar that much.
And certainly Wozniak had no impact at all; I met him once or twice, but he was in a different space. I don't remember any of the other execs like Markkula paying any attention to it.
Sun: I remember a conversation about Dean wanting to manufacture this--
Yurchenco: Right, but I wasn't privy to any of that.
Sun: That was a separate conversation. I suspect that was-- Dean and Jobs had some kind of a relationship that went back prior to Apple, and that was part of Dean's private conversations with Jobs, and obviously nothing came of that.
Pang: Jim Sachs mentioned a visit to Xerox PARC to look at their mouse in action.
Yurchenco: Yeah, I remember going over there. I remember meeting Alan Kay, but I don't remember particularly that anything came of it in terms of applying to this development project. It was more like, "Whoa, what is this, this is interesting," and-- what was Alan pushing-- something-book--
Pang: Dynabook.
Yurchenco: Dynabook? Yeah, whatever-- he was envisioning today's laptop. So he was obviously a person who thought pretty far in the future, but there was nothing that really specifically came out that aided or hindered this investigation.
Pang: So had you already been at work on the mouse when you went up to Xerox PARC?
Yurchenco: I don't recall. It wasn't something that struck me one way or the other as being important to this process. It was just a nice field-trip more than anything.
Sun: Xerox PARC was a popular place for field trips: I remember in school going on trips and seeing the prototype mouse, and seeing the Star, and the user interface, so it was just a popular thing to do.
Yurchenco: I only had that one visit, and I never went back.
Yurchenco: Dean and I spent time as well developing the early Macintosh models-- I don't know if you're aware of that.
Pang: No.
Yurchenco: We actually built the first model of what because the first production Macintosh, in Dean's shop.
Pang: So this would have been after Jobs had taken over the project?
Yurchenco: No. Jerry was working on it-- Jerry transferred over and started working on it, and I assume Jobs was heavily involved at that point. But what sticks in my mind is that we were working on it the same time they were televising the first Space Shuttle launch, and somehow there's a connection in my mind of that time frame. It would be interesting to see if it's true (laughs).
But I remember when I first joined H-K there were some sketches floating around of things that were predating, were early predecessors of what became the Mac, floating around the office. There had been some work done there. David and Dean had done some conceptual work on it. So it has roots that go pretty far back in our company.
Pang: Jim Sachs had mentioned some kind of secret project that Steve had talked to David Kelley about, but didn't offer much in the way of detail. I haven't figured out from the Apple side of the papers what that would have corresponded to.
Yurchenco: Well, there were definitely drawings of units that had basically a monitor with a CPU in it floating around, that in some ways looked a lot like what became Mac. Now what's happened to that stuff, I don't know. But I do remember actually working on the models of some of Jerry Manock's very early sketches of that thing to build-- working appearance models.
There was quite a bit of overlap between development of Mac and development of Lisa. Part of our company was working on Lisa, in particular Douglas Dayton. There were endless, endless revisions to Lisa keyboards, and PAG cards, and so forth-- I mean, Douglas got a kick out of it because his rev block fell off one sheet of paper and started growing down the bottom of another one, with double letters, with "CCCC:" and so forth. Just endless, endless noodling changes for no reason, other than, I suppose, vanity.
But at the same time Mac work was getting started and going on. So there was quite a bit of overlap in people at that time; eventually it became totally polarized between the Mac people and the Lisa people. But I don't think that people at H-K quite realized the depth of the polarization; I think we were really naive about that detail. I mean, we were friends with Manock, and we were friends with Dresselhaus. Manock became associated with Mac, and Dresselhaus stayed as part of the Lisa team-- I don't know whether there was any particular bad blood between the two of them, but certainly Jobs encouraged it, with his attitude-- his "take no prisoners" attitude-- with however he described the people in the Lisa group.
I certainly don't ever recall us ever being drawn into that, and probably we were a little naive in terms of the relations we were trying to maintain on both sides (laughs). I think probably if we'd understood that a little better, we'd been a little more effective in terms of what we were doing.
Sun: We just wanted to design here.
Yurchenco: Yep, basically.
Pang: There are two balls you've got here. It looks like one of them is rubber-coated....
Sun: I can tell you a lot of stories about these-- this was one of the things I worked on. Sometimes the ball slipped, and we were trying to figure out why. So I ended up-- [gets picture] This is a scanning electron microphotograph of the steel ball's surface. We were trying to understand whether or not after some use the surface was changing. And we brought in used balls to see if the balls were getting less rough, or whether the peaks and valleys were being leveled with fill from bits of Formica from table surfaces. So we were taking an old record turntable and putting pieces on that, and making a little robot arm that would test to see how many miles it would run before it would slip. In the end we had to coat the balls with rubber, and so we had to justify that cost of coating.
Yurchenco: It turned out that the textured surface of the ball picked up crap. It wasn't just from the Formica, it was plastic wearing off the mouse parts themselves. These wear surfaces here, they shed little bits of plastic, and the first thing the ball rolls over and the first thing it does is pick them up!
Sun: [points to underside of mouse] These little feet would begin to deposit themselves on the work surface.
Yurchenco: The things we were looking at using were just basically very low-quality ball bearings, because they were very precise but incredibly cheap. So were looking at ways of texturing the surface to change its coefficient of friction, and other techniques, but it never did pan out, were were never able to use an uncoated ball in the long run. We had to go to a rubber coating on it. They'd work for a while, but eventually start skipping, and just not cut it.
Sun: There was a fair amount of working going into these rollers-- I think these original rollers were pour-on.
Yurchenco: Right. But when the idler wheel came along, we realized we could use hard rollers, and just went to over-molded ABS or polycarbon or whatever that material is. You wanted them rigid, because a change in diameter in a soft roller would affect the accuracy of the mouse: depending on how much pressure you put on the pour-on, because the ratio of the diameter of the roller to the diameter of the ball would change a little bit, and you'd lose accuracy. So it ended up that you had to go with a rigid roller for that reason alone.
Sun: Right. The bigger challenge was reducing the friction from the idle roller and how much energy it took out of the system. We also played some with stepping down the shaft diameters, but I don't see that in these models.
Pang: Wasn't there also a problem with the shafts bending if you dropped them from too great a height, and the stepped-down shafts were in part intended to strengthen them?
Yurchenco: Well, the idler wheel would never have that problem, because it was spring-loaded and would just move out of the way. This shaft ended up being quite well-supported in this design, because this thing is in this housing, the amount of travel this thing can take is pretty high. But I don't recall it ever really being an issue.
Sun: I recall there being some discussion, and we did some tests, but there weren't very many units who had that problem. Because if you think about it, you have to hit it pretty directly.
Yurchenco: In this design, there's a long unsupported length. And in this design here, the unsupported length is pretty darn short. And there's a tiny bit of clearance between these shafts....
Sun: I don't know who has those test results, but I remember getting them back and saying, "Oh, I'm glad it wasn't such a big deal."
Yurchenco: Yeah.
Sun: If you make the ends of the shafts smaller where they are supported, it also reduces the friction.
Yurchenco: But we ended up not doing that because it was too expensive. We just went with a smaller diameter.
Sun: I remember working with Jim on the tolerance of the emitter-detector pairs. They just weren't made to be as precise as we needed them to be. Optron, who made these pairs-- we had a high reject rate at first. Eventually we got them to figure out how to make them to the precision levels we needed, but that was a challenge as well. The trade-off between precision in how much light and the alignment of the light with the molded lens, versus the mechanical alignment-- we were having conversations about whether we should do that, it's a very elaborate tolerance analysis to try and understand who should tightening up their tolerance-- whether it should be a tightening of the optical tolerance, or a tightening of the mechanical tolerance. But we were pushing the limits of the mechanical tolerance already, and they weren't going to get any better (laughs). So we went back to the optical system, and it's amazing it all worked out.
Yurchenco: It turns out you can have an incredible amount of sloppiness in the system and it still works. You look at mice today, and they're just slammed together. You go to a mouse line, and there people sitting there-- I've been in mouse lines all over Asia, and there was this level of precision we thought we needed, and maybe at the time we did, because of the optical components, but it's just gone out of the system now.
Pang: Why did the Apple mouse have one button?
Yurchenco: All I know is rumor. And the rumor is that word came down from high that it would have one button because it was simpler. The whole game Apple was playing was simple user interface. If you had two buttons, you had to learn what each one did; with one button, that one button does everything. Apple still works with one button. When I use a PC, I don't have a clue what those other buttons are for!
Sun: The only story I have on that is also anecdotal. Someone else told me that Chris Espinosa said that it would be easier for him to write the documentation if there was only one button, so he wouldn't have to talk about "left button" and "right button." Which is really the same point that Jim is getting at.
Yurchenco: I don't remember strong arguments for two buttons from anybody. I don't think there was much strong support from it at Apple at all. There may have been some software guys who wanted it because they could put more bells and whistled on, but I don't ever remember any screaming arguments there. I don't think it was a big decision in the end.... It's probably one of those osmosis decisions: the consensus is there, and people just say, "Yeah, it's going to be one button."
One little anecdote which I still find amusing. We had this door on the bottom of the mouse, and I needed to mark it in two positions. I decided to have an "O" for open, and "L" for locked. I just made that decision arbitrarily one day at my drafting board. No one ever questioned it: nobody ever asked, "Why did you do that." And ten years later, mice made by completely different companies had Os and Ls on them, and I would be willing to bet that nobody knew what that meant or why that was there. It was one of those legacy things that has roots in no conscious decision other than "I gotta put something down," and it just gets blindly copied forever and ever. I don't see it any more, but I saw it for at least ten years after.