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  A Little More About the Transistor

  The transistor will likely go down as one of the greatest inventions in modern history, ranking right up there with the car, the telephone, and Gutenberg’s printing press. William Shockley and his team at Bell Labs invented the transistor in 1947.

  Put most simply, a transistor is a tiny electronic device to control the flow of electricity. But a transistor is more than that. It has two key abilities: the first is to amplify an electric signal, and the other is to switch on or off (1 or 0), letting current through or blocking it as necessary.

  Transistors are in practically all modern electronics these days, from musical birthday cards, to your car, to your personal computer. Since 1947—and this is what has made the computer revolution possible—it has become cheaper and cheaper to pack more transistors onto a computer chip every year. (This is known as Moore’s Law, which Intel founder Gordon Moore defined in the 1960s. He said that every year manufacturing would get so good that double the number of transistors would be able to fit on a chip for the same price.)

  A simple logic gate comprises about twenty transistors, compared to an advanced computer chip in a modern (circa 2006) computer, which can include as many as a billion transistors.

  thing. We also had to go up on the roof and string antennas of a certain length, to be right for the signals I needed. This was the beginning of learning the kinds of things I would need later to design and assemble computer boards like the one that later became the Apple I.

  I loved my transmitter and receiver. They were such standouts in ham radio quality—these days, I even see these models featured in radio museums and collectors’ magazines. I didn’t really get into talking to the other ham radio operators—they were so much older than me and we really didn’t have anything except for the ham radios in common. So after building it, I have to admit the whole thing got a little boring. But this experience was a major one. For one thing, I’m fairly sure I was one of the youngest ham radio operators in the country. That was huge for me. But even more importantly, I learned all about the process of getting a ham radio license—what I needed to know, what I needed to build the equipment—and then I built the radio. It gave me a lot of confidence for doing all kinds of other projects later on.

  So my dad ended up being a key influence here, too. I mean, he even got his ham radio license with me—studying with me and taking and passing the test! The thing is, he never really tried to lead me in any direction or push me into electrical engineering. But whenever I got interested in something he was right there, always ready to show me on his blackboard how something worked. He was always ready to teach me something.

  • o •

  My mom really pushed me along, too. In the third grade, when I started doing math flash cards at school, my mom practiced multiplication with me the night before we’d have to do them in school. And as a result, in school I was the only boy who

  could beat the girls at them. I remember a teacher said, “Wow, that’s incredible. I never had a boy before who could beat the girls at flash cards.” And again, that was high praise. Girls always seemed to get better grades than boys, I thought. And then I thought: Whoa. My gosh, I’m good at something—math—and I’m going to work harder at it. And I worked harder and harder to try to always be the best, to try to always be ahead. That’s what really put me ahead at such a young age, this drive to keep my lead. I had a teacher in both the fourth and fifth grades, Miss Skrak, who really praised my science projects, like I was the smartest kid in the class because I knew science so well. As you’d predict,

  I accelerated even more later on. In sixth grade I was doing electronics projects most kids never figure out how to do even in high school-level electronics. So I was very lucky with all my teachers, especially Miss Skrak. She came along at just the right time in my life.

  • o •

  At about this time, there was another lucky accident. I found this article about computers in one of the old engineering journals my dad had hanging around. Back then, back in 1960, writing about computers wasn’t common at all. But what I saw was an article about the ENIAC and a picture of it. The ENIAC— which stood for Electronic Numerical Integrator And Computer—was the first true computer by most people’s definition. It was designed to calculate bomb trajectories for the military during World War II. So it was designed back in the 1940s.

  This journal had all kinds of pictures of huge computers and articles describing them. These computers were unlike anything I’d ever seen. One picture showed a big round tube that looked like a TV tube. And the article explained that the round tube was where these huge computers stored data. It used phosphor lights and then it could read if the phosphors (lights) were on or off— just like the digits 1 and 0 on today’s computers can be interpreted as On or Off—and then it could reset them quickly. This, the article explained, was actually a way to store data, and I was just intrigued by that idea. I was about eleven years old at the time.

  Suddenly I realized that some incredible things were just starting to happen with computers at these very early stages. Of course, they were nowhere near the point of making computers affordable or usable for the world. They weren’t even talking about a point where anyone could buy a computer and put it in your house and learn how to use it yourself. I thought that would be just the best thing, and that was the dream—The Dream, I

  have to put that in capital letters—because it was the single force that drove me for years afterward. How to make The Dream come true. I thought about that constantly.

  There were so many incredible things happening with computers at that time, and I would never have known about them if I hadn’t been too shy to do anything but read magazines at my house. The amazing thing was that at this early stage in my life, I’d managed to find this journal Dad had with this stuff in it. This was a magazine most people were never supposed to see or even be interested in because it was targeted to high-level government engineers.

  After that, I was addicted. I started reading and rereading this journal and others my dad had. I remember one day finding an article on Boolean algebra. That’s the type of mathematics computers use. And I learned about De Morgan’s Theorem, which is what Boolean algebra is based on. And that’s how logic became the heart of my existence, there in the fifth grade. I was learning that formula and figuring out how to use it so I could swap ANDs and ORs in logic equations. In logic, for instance, you might ask if a word starts and ends with a vowel. Well, then the formula would be an AND—there’s a vowel at the beginning and a vowel at the end. That’s AND in Boolean algebra. But what about a word that starts with a vowel but doesn’t end with one, or the other way around, but not both? That’s an OR statement in Boolean algebra.

  And in this journal they had diagrams of AND gates and OR gates and I copied them, learning to draw them the standard way.

  For instance, a half-moon shape with a dot in the middle represents an AND gate. If it has a plus sign in the middle instead of a dot, it’s an OR gate. Then I learned how to draw a picture that represented an inverter—it’s a triangle pointing to the right with a little tiny circle at the very end of its tip. What’s funny is, I use these very same symbols when I design electronics to this day,

  and I learned all this in my room with these journals in front of me on my bed in fifth grade.

  Here’s what was amazing to me back then. I thought to myself: Hey, at my current level of fifth-grade math, I am able to learn the math used by a computer—De Morgan’s Theorem, Boolean algebra. I mean, anyone could learn Boolean algebra and they wouldn’t even need a higher level of math than I already had in fifth grade. Computers were kind of simple, I discovered. And that blew me away. Computers—which in my opinion were the most incredible things in the world, the most advanced technology there was, way above the head, above the understanding, of almost everyone— were so simple a fifth grader like me could understand them! I loved that. I decided then that I wanted to do logic and
computers for fun. I wasn’t sure if that was even possible.

  To say you wanted to play with computers in those days, well, that was so remote. It was like saying you wanted to be an astronaut. It was 1961; there weren’t even real astronauts yet! The odds of being one seemed really slim. But logic was different. I could see that it just came so easily for me. And it always would.

  So that’s how computers became the heart of my life straight through. As a matter of fact, computer logic was something I eventually became better at than probably any other human alive. (I can’t be sure of that, of course. Maybe there were really high-up people in colleges who were as good at applying De Morgan’s Theorem in their heads.) But by the time I designed the first Apple computer, logic was my life. I know it sounds unbelievable, but I just loved logic and everything about it, even back then.

  • o •

  I was in elementary school and junior high at a time when science projects were cool—when you weren’t strange if you did one, and you got celebrated if you won an award. So I got celebrated a lot. My science fair projects are some of the things I am still proudest of. We’re talking third, fourth, fifth, sixth, and

  eighth grades here. (For some reason, I didn’t enter a project in the seventh grade.) And these projects were hard, harder than kids many grades ahead of me could ever pull off, and I knew it even then. I put some science projects together that, for that audience of kids and judges, just blew their minds. I was like a hero, and I won all kinds of awards, including top honors at the Bay Area Science Fair.

  The science fairs gave me the feeling of what I was and could be in the world, just by entering something good in a science fair. The teachers recognized something different about me immediately; some of them even started calling me Science Whiz because I had all these great projects in the science fairs. And probably as a result of that, by sixth grade I was doing electronics projects few people in high school could even understand yet. Those kinds of acknowledgments and those kinds of achievements made me want to keep working at those tilings until they would be my things in the world.

  • o •

  My first science competition was in third grade, and I won. But the project was pretty simple, really. Basically I put together this little contraption with a light and a couple of batteries and a little wire—all mounted on a piece of wood. It was a working flashlight! A lot of people were surprised by that, and I won. No big deal, it turns out, because I felt inside it wasn’t really that impressive, and I knew I would do even better the next time.

  It was in the fourth grade that I did the first project that really taught me about things I would need later—physics, electronics, and the project materials. It was an experiment to see what would happen if you dipped these two carbon rods into any liquid of your choice. The carbon rods were connected by a wire to a lightbulb and an AC plug. By dipping the carbon rods into the liquid, the liquid in effect became one of the “wires.” It could either act as a good wire or a bad wire—that is, it could conduct

  electricity well or it could conduct electricity poorly. If the lightbulb glowed, brightly or dimly, you could see how well the liquid could conduct electricity.

  I used every liquid I could get my hands on—water, Coca-Cola, iced tea, juice, beer. Which liquid conducts electricity best? (The answer turned out to be salt water.) This is an extremely important thing to know if you want to understand, for instance, hydroelectric machinery or even just plain old batteries.

  • o •

  But the next experiment, man, that was a big one. What I did was build this giant real-life electronic model representing what each of the ninety-two atoms in the periodic table looks like in terms of its electrons.

  In case you don’t remember, electrons orbit the center of an atom in much the same way planets orbit the sun. The Earth, for instance, has a different orbit than, say, Neptune.

  My project aimed to demonstrate, with the click of a switch, how many electrons orbit each atom in the periodic table, and which orbit around the nucleus they should be in. For instance, if I hit the switch for hydrogen, one light would turn onA in the orbit nearest the center of the hole, which represented the nucleus.

  To pull off this project, I had to drill ninety-two holes in a big aluminum sheet. The holes were located toward the bottom; each one would hold one switch corresponding to each element. One switch would be for hydrogen, one for gold, one for helium, and so on.

  Now, I painted a very large picture resembling a bull’s-eye target—concentric circles in different colors, with a tiny target in the middle to represent the center of the atom, which is the nucleus. And I had to drill ninety-two holes into the big orbit picture, several in each orbit, corresponding to where the electrons could be in an atom.

  The end result was this. Ask me to show you the electrons for any of the ninety-two natural elements. Let’s say oxygen. I would hit the oxygen switch, and the eight lights representing the eight electrons that rotate around the oxygen atom would turn on, all in the proper orbits.

  I knew what the proper orbits were because I’d used this big reference book called The Handbook for Chemistry and Physics.

  This project ended up getting terribly complicated, because by the time I was dealing with all ninety-two elements I was stuck with dealing with ninety-two different sets of switches.

  That got so tough I finally had to use the information my dad taught me about the diode, which is the first electronics part I ever learned about, really. Unlike a resistor, a diode is a one-way street. You can send electrons—that is, electricity—-just one way. Electricity can go through, but it can’t come back through. If you try, it will short everything out. And this was a problem because I’d gotten to the point where if I tried to turn on some middle-level element and its electrons, I wound up with a feedback path that ended up turning on a bunch of lower elements and extra electrons that really didn’t belong there. Anyway, I needed a solution, and that’s how I learned all about diodes.

  Along with this huge display, I also displayed a large collection of elements. You know, jars of beryllium, pieces of copper, even a bottle of mercury. I got a lot of these samples just by asking a professor at San Jose State to donate them to me.

  And yes, I won. First place. Blue ribbon. And that was cool.

  But it wasn’t the most important thing. Looking back on it now, I see this was an amazing learning experience, just classic. My dad guided me, but I did the work. And my dad, to his credit, never tried to teach me formulas about gravitational power and electric power between protons, or stuff like what the force is between protons and electrons. That would have been way

  beyond what I could understand at that point. He never tried to force me to try and jump ahead because I wouldn’t have learned it. I wasn’t ready for that level of knowledge.

  • o •

  In sixth grade, small step by small step, I learned how to build AND and OR gates, the basic building blocks of computer technology. Digital circuits figure everything out—and I mean everything—based on what is on (Is) and what is off (Os).

  I was really getting into logic. My dad had helped me understand the concept of logic earlier by using the classic paper-and-pen tic-tac-toe game. This game, if you understand the logic, you will never, ever lose. That’s what I based my next project on: the tic-tac-toe machine. The machine I built would never, ever lose. It is so totally a logic game, but it is also a psychological game because you can beat someone who thinks they can never be beaten. If the X is here and the other X is over there, what should the outcome be? This plywood was covered with parts and it was a huge project. And having a huge project is a huge part of learning engineering—learning anything, probably.

  Doing long, long jobs that aren’t just some real simple quick thing like a flashlight, but things that take weeks to build, really demonstrates that you’ve mastered something great. Like, for instance, creating a computerized tic-tac-toe machine that really works by logic.

  U
nfortunately, though, the system didn’t win. It blew up. What I mean by blew up is, the night before the competition, some of the transistors started to put out smoke. Obviously something was wrong. I knew it was going to take forever to find out what piece of equipment had blown and there was no way I was going to be able to do this in time for the contest. What a disappointment, because I like to win. I always, as early as I can remember, wanted to be the best at things. And I often was, as luck had it.

  But I also thought at the time that it didn’t mean as much to

  me at that point, just winning the science fair, because I knew, and my dad knew, that I had actually built this fairly complicated logic machine and it worked.

  I mean, even as a kid it was obvious to me what the important thing really was. I said to myself, Look, showing someone an award from a science fair is not as important as knowing you already have the award somewhere at home. And that’s not as important as having earned it, even if you don’t have the award at home at all. And that’s not as important as the most important thing: that you’ve done the learning on your own to figure out how to do it. I did that learning on my tic-tac-toe machine, and it was very, very close to being done and complete. I’m still proud of it. For me it’s the engineering, not the glory, that’s really important.

  • o •

  Okay, so I’d built that tic-tac-toe system basically by putting together electronic gates. The idea was to put the gates together into a system of transistor circuits that would never let you beat it. And as I said, I came up with the rules by playing all possible games.