focus on the computer
Lets take a close look at the computer as an example of an electronic device. A computer contains integrated circuits, or microchips, that consist of millions of tiny electronic components. Information is encoded in digital electronic signals. Rapid pulses of voltage switch electric current on and off, producing long strings of 1s (current on) and 0s (current off). The 1s and 0s are the letters of the code, and a huge number of them are needed. One digit (either 0 or 1) is called a bit, which stands for binary digit. Each group of eight digits is called a byte, and a billion bytes is called a gigabyte. Because a computers circuits are so tiny and close together, the computer can be very fast and capable of many complex tasks while remaining small. The parts of a computer that transmit, process, or store digital signals are pictured and described in the Figure 1.1. They include the CPU, hard drive, ROM, and RAM. The motherboard ties all these parts of the computer together. The CPU, or central processing unit, carries out program instructions. The hard drive is a magnetic disc that provides long-term storage for programs and data. ROM (read-only memory) is a microchip that provides permanent storage. It stores important information such as start-up instructions. This memory remains even after the computer is turned off. RAM (random-access memory) is a microchip that temporarily stores programs and data that are currently being used. Anything stored in RAM is lost when the computer is turned off. The motherboard is connected to the CPU, hard drive, ROM, and RAM. It allows all these parts of the computer to receive power and communicate with one another. Q: Which part(s) of a computer are you using when you type a school report? A: You are using the RAM to store the word processing program and your document as you type it. You are using the CPU to carry out instructions in the word processing program, and you are probably using the hard drive to save your document.
what are electronic devices
Many of the devices people commonly use today are electronic devices. Electronic devices use electric current to encode, analyze, or transmit information. In addition to computers, they include mobile phones, TV remotes, DVD and CD players, and digital cameras, to name just a few. Q: Can you think of other electronic devices that you use? A: Other examples include game systems and MP3 players.
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a single microchip may consist of millions of tiny electronic components.
--> a. true b. false
in a computer, information is encoded by repeatedly switching current on and off.
--> a. true b. false
which string of digits represents a byte?
a) 0101 b) 010111 --> c) 01011100 d) none of the above
the part of a computer that carries out program instructions is the
a) hard drive. --> b) central processing unit. c) read-only memory. d) none of the above
the part of a computer that stores information permanently is the
a) random-access memory. b) motherboard. --> c) read-only memory. d) none of the above
No diagram questions associated with this lesson