Often also called an "endless loop," this is a piece of coding that accidentally or by design repeats indefinitely. It is an order created by a computer program delivered to a computer processor. Each instruction, at its most basic level, is just an order for the computer to do something like "add" or "subtract" with the Is and Os that make up computer data. See a. This is a key term in computer technology. Almost all computers today use interrupts.
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Often also called an "endless loop," this is a piece of coding that accidentally or by design repeats indefinitely. It is an order created by a computer program delivered to a computer processor. Each instruction, at its most basic level, is just an order for the computer to do something like "add" or "subtract" with the Is and Os that make up computer data.
See a. This is a key term in computer technology. Almost all computers today use interrupts. For instance, if you hit the G key while a program is running, the system will pause, notice that the keyboard has interrupted it, and run the program that will display "G" on-screen. This refers to a signal that comes from a device attached to a computer-or from a program running on that computer-that causes the CPU system software to stop and pay attention to what should be done next.
A unit of computer storage equal to approximately 1, bytes of data-more precisely, 2 to the tenth power, or 1, bytes. It is an elementary building block of a circuit. Most logic gates have two inputs and one output. A single computer circuit that has several points of input but only one point of output. At any given moment, every terminal is in one of the two conditions-low 0 or high 1 -defined by the voltage level. The state, 0 or 1, changes often as data is processed.
For example, the AND gate is called that because if 0 is false and 1 is true, the gate acts the same way as the standard AND operator in Boolean algebra. With an OR gate, the output is true or 1 if either or both of the inputs are true or 1.
If both inputs are false 0 , then the output is false 0. It reverses the logic state. It acts in the manner of the logical operation "and" followed by negation. The output is "false" if both inputs are "true. Its output is "tine" if both inputs are "false. Its output is "true" if the inputs are the same, and "false" if the inputs are different. Using combinations of logic gates, complex operations can be performed.
In theory, there is no limit to the number of gates that can be arrayed in a single device. But in practice, there is a limit to the number of gates that can be packed into a given physical s.
Arrays of logic gates are found in digital integrated circuits ICs. As IC technology improves, the physical s. That means faster chips in smaller packages-and increasing computer power at decreasing prices. See bit; byte. The basic-level language that a computer can understand, this refers to a stream of binary digits-Os and Is-or bits. Typically referred to as "RAM" short for random-access memory , memory is typically located on a set of microchips located physically close to the computer processor.
When you turn a computer off, all information held in RAM disappears. The electronic holding place for instructions and data that your computer needs to reach quickly. Intel founder Gordon Moore in made the following now-famous observation: that due to improvements in manufacturing, every eighteen months engineers would be able to double the number of transistors on a chip. Also sometimes referred to as the "main board" and the "system board.
OR gate See See logic gate. On a screen, the device draws a graph of voltage over time. A laboratory instrument commonly used to display and a. Another common term for the CPU is "microprocessor. PROM Short for programmable read-only memory, this is a type of computer chip with data that can only be changed with a special machine. RAM Short for random-access memory, this is the type of memory chip a computer uses for short-term storage and calculation.
This kind of "memory" is not to be confused with the permanent storage a hard disk or CD-ROM drive provides. RAM chips lose their contents whenever you power down the computer. See Short for random-access memory, this is the type of memory chip a computer uses for short-term storage and calculation. See memory. For example, a computer instruction might command that the contents of two registers be added together.
A register is typically large enough to hold a bit instruction, though there are smaller registers, such as half-registers, in some computer designs. In a computer processor, a register is a holding place for any kind of data, including a storage address, individual characters, or a computer instruction.
Measured in ohms. Denoted by the representation R, this is the opposition a given substance offers to the flow of current. Typically, resistors are mounted on a printed circuit board or built into a chip. An electronic component that controls the flow of current in a circuit by resisting, or turning away, electricity. ROM Built into every computer, ROM, short for read-only memory, is computer memory that contains data that can only be read. It is designed to store data permanently, and not be erased or modified by a user.
A ROM chip contains the program that allows a computer to be restarted and still remember its basic settings every time. The ROM is typically powered by a small long-life battery. See Built into every computer, ROM, short for read-only memory, is computer memory that contains data that can only be read.
A more complicated signal consists of an alternating current AC to carry more than one stream of data at a time. Most simply, this is an electric current or field used to carry data from one place to another. A waveform is a pictorial representation of how alternating current AC varies over time. The most familiar alternating current waveform, varying with time. The term "primary storage" generally refers to the place in memory where data is held; the term "secondary storage" generally refers to permanent data holding on hard disks, tapes, and other storage media.
Refers to the place in a computer where data is held in electromagnetic or optical form for access by a computer processor. Invented by three scientists at Bell Laboratories in , this was a key invention that enabled computers and computerized devices.
Before transistors, vacuum tubes were in use-but they quickly became obsolete after the transistor was widely available for the purpose of regulating current voltage.
Transistors act as incredibly tiny and effective switches for electronic signals. See vacuum tube. A tiny device for regulating electronic signals. It is now mostly obsolete, having been replaced in electronics by the transistor. See Also known as an "electron tube," a vacuum tube was once commonly used to amplify electronic signals.
See transistor. First, I must thank my parents for helping me find my own values and for a. This book could not have happened without believers in the publishing industry. John Brockman did a splendid job in finding our publisher, W. We lucked out to get the legendary nonfiction editor Angela von der Lippe on this book.
Her true interest was part of what I needed to get this project done. Countless others had important roles as well. More thanks than I can ever give should go to Gina Smith, who had the drive to create this book and who met with me on countless occasions to put it all together. Just having a schedule and a purpose and prodding made all the difference. We would get together and speak stories into recorders, and go over and over the paragraphs to get the right sound.
Thanks also to Michele Earl for a lucky and unusual encounter that led to my meeting Gina. I have to thank those responsible for my successes in life. To Miss Skrak for seeing so much in me.
To Mr. McCollum for finding so much valuable education beyond the school he worked for. To Steve Jobs for wanting to do Great and Big things. Most of all, thanks to Allen Baum, who was involved in some way in so many of the big steps in my computer life.
And for his parents who appreciated jokes and humor and had such good values in life. My memory of them still brings tears. I must thank my first wife, Alice, without whom Apple would never have happened for me; Candi, my second wife, for the most wonderful creations of Jesse, Sara, and Gary; and my third wife, Suzanne, for Hard Rock Cafes and bungee jumping and for being so wonderful and decent.
Friends who made this possible for me, digging up needed photos and reminding me of stories, included Laura and Dan and Alex. Sharon was the most loyal in all cases, always looking out for me and making sure needed things got done.
Gina thanks her friend Michele Earl for introducing her to Steve at a rock concert. Within a week of our meeting, the iWoz iWoz book proposal was in to our phenomenal agent, John Brockman. Gina thanks the exceptional team at Norton, including editor Angela von der Lippe, her a. Thanks also to Keith Blate and David Street, Steve Wozniak fans and editors who spent much time reading the earliest drafts of this book.
Gina also wants to thank her wildly supportive family and friends, without whom this book could not have been completed: Tops on the list are her ever-patient husband, Henry, and their small son, Eric. Special thanks go to her beautiful and intrepid late mother, Emilia Sladjana Djuran Ferguson, for teaching her that, in America, it always pays not to be afraid to talk to the big shots! And to her father, David A.
IWoz_ Computer Geek to Cult Icon Part 3
Synopsis Edit Wozniak starts his autobiography with a description of his parents, some of their history, and describes how his father had a top secret job involving electronics. He goes on to describe how his father took the time to describe to him, in detail, how electronic components work. He cites this as a major reason for his later success. Wozniak discusses how he decided to enroll at the University of Colorado, Boulder. Wozniak describes his encounter with the first successful video arcade game , Pong , at a bowling alley with Alice then his fiancee. He describes just staring at it, amazed that computers could be used in such a way.
IWOZ FROM COMPUTER GEEK TO CULT ICON PDF
IWoz_ Computer Geek to Cult Icon Part 4