A bit more than fifty years ago, in 1960, Sony introduced the first transistor radio. At the time, and for several years thereafter, claiming a new device had transistors was used as a marketing ploy, much as high definition is now. On the outside of the case, most new radios would boast how many transistors they had on the inside. I recall, back when I was a kid, my dad gave me such a transistor radio. I loved that thing. Besides picking up the normal AM and FM signals, it could also pick up short wave radio broadcasts. And on the outside of the case, in rather large letters, it announced that it had “8 Transistors.”
For those of us born a more comfortable distance from the apocalypse (to borrow a phrase from the comedian, Emo Philips), we may remember the old glowing vacuum tubes that used to fill radios and televisions. Periodically, when the TV or radio would stop working, we’d open up the back of our machine and peer inside for burned out tubes, which we’d then take down to the grocery store and plug into a big metal machine they had there to see if the tubes really were working or not. If we were lucky, we’d find the blown tube and then study the numbers on it so we could grab a replacement. What did those tubes do in our old TVs and radios? They were used to amplify, switch, or otherwise modify or create electrical signals by controlling the movement of electrons. More simply, they were what made our magic boxes work. At most, our old radio or televisions, that hummed and took minutes to warm up, might have a dozen tubes stuffed inside them. Computers from the era were rare, noisy, enormous and unreliable. The first computers, such as the Colossus from World War II ran on perhaps five hundred vacuum tubes that were constantly burning out and needing to be replaced. Operators were lucky if a computer could actually do anything useful between breakdowns.
Even so, vacuum tubes were critical to the development of electronic technology, which drove the expansion and commercialization of radio broadcasting, television, radar, sound reproduction, large telephone networks, analog and digital computers, and industrial process control. Some of those applications pre-dated electronics, but it was the vacuum tube that made them widespread and practical.
The introduction of transistors was transformative in the realm of all things electronic. Transistors manage to do the same job that all those old tubes did. Because they are smaller, use less electricity, cost far less to manufacture, they don’t hum, glow or need to warm up. More importantly, they don’t burn out. That’s why transistors very quickly replaced the vacuum tube in all electronic devices within just a few decades after their invention.
The transistor was invented by several people working together at AT&T’s Bell labs in 1947. John Bardeen, Walter Brattain, and William Shockley were instrumental in making them practical. The first silicon transistor was then produced by Texas Instruments in 1954, and commercialization of the device soon followed.
The transistor is one of the most important inventions of the twentieth century. Today, transistors are ubiquitous. No marketing department would ever think to emblazen the fact that a new device has transistors in it. We take them entirely for granted. If you were to open up an old transistor radio, you could see the transistors soldered onto the circuit board. But if you were to open up any modern gadget, you wouldn’t be able to locate the transistors unless you had a high powered electron microscope. And you would be hard pressed, even then, to count them all.
A modern computer has a central processing unit, made by either Intel or AMD. Intel’s first central processing unit for micro computers was released in 1971. It contained 2300 transistors. When Intel first released the Core i7 processors in 2007 they had 781 million transistors on them. And the processors containing those millions of transistors were only about an inch and a half by an inch and a half square, and maybe an eighth of an inch thick. The next generation Core i7 that followed had well over two billion transistors on it. And so it goes.
The number of transistors on a processor chip, packed into the same amount of space, doubles about every eighteen to twenty-four months. This is known as Moore’s Law, named after the cofounder of Intel, Gordon Moore. He had first made the observation in the April, 19, 1965 publication, Electronics Magazine. Intel has kept up that doubling of transistors on chips for the last forty years with no sign of slowing anytime soon.
As if that weren’t enough, the cost to the consumer for computer chips has dropped rapidly every year. In fact, if the price of automobiles followed the same pattern and percentages as the cost of transistors, cars would today cost less than the gasoline used to fill their tanks.
In 2008 about ten billion computer processor chips were manufactured. Every year, that number grows.
Every television, every cell phone, every microwave, and every automobile sold today has thousands, if not millions of transistors inside of them. In fact well over sixty million transistors are manufactured for each man, woman and child on Earth every single year. Our current civilization, as it functions today, simply could not exist without the transistor.