Introduction to Computer Hardware

Hardware is anything you can physically touch. The Encyclopedia on the CD-ROM is software. The encyclopedia doesn’t actually exist. It is a set of instructions for the computer to follow, called a program, which is software. Hardware vs Software

Computer Hardware Input device (used to put information into a computer, like a keyboard or mouse) Output device (used to get information from a computer, like a monitor or printer) Storage device (used to store data or programs) Can be permanent (like a CD or hard drive) or temporary (like RAM) Process device (used to process or direct information, like the microprocessor or motherboard)

Computer Hardware Motherboard Central computer board by which all other devices are connected. Think of this as a city street. In fact, information travels these streets by bus! The CPU CPU ZIF Socket Expansion Slots RAM

Computer Hardware Hard Drive (Storage) –Permanent magnetic storage device. –Don’t move the computer while it is accessing the hard disks. –Don’t put a magnet next to the disks. –When disposing of a computer, destroy the hard disk to prevent data theft. “Platters” are metal disks coated with a magnetically sensitive coating Read/Write heads for each platter These platters spin at speeds like 120 rotations/second!

Computer Hardware RAM (Process device) –“Random Access Memory” (temporary memory) –Information is stored as electrical impulses and is a very fast storage medium. –Information disappears after the computer is shut down. RAM connects directly to the motherboard. Some devices, such as a video card, have their own RAM.

Computer Hardware Expansion Cards (usually output devices) –Expand the computer’s capabilities to: Play music Display graphics Communicate to other computers Use the telephone And more… Expansion cards enable the computer to expand its capabilities. This one, for instance, is a network card which allows the computer to share information with other computers.

Computer Hardware The CPU “Central Processing Unit” Fetches, decodes and executes program information Considered the computer’s “brain”. It can do no original “thought” like our brains. Contains millions of “switches” called transistors all contained in an area smaller than an adult fingernail. The microchip itself. Numerous pins for transmitting information. Circuitry leads from the pins to the CPU A ceramic protective outer coating

Computer Hardware Computer chips (RAM) and CPUs are made of silicon (sand), the most common stuff on earth. They are baked into glass and etched with patterns, photo-resist layers and special chemicals. A silicon ingot is baked and sliced into wafers using a diamond saw Each tiny square on this wafer is a microchip This wafer is only 4 inches in diameter

Peripherals The monitor, (also known as a CRT, after the Cathode Ray Tube inside that displays the picture), is measured in size with a ruler, diagonally across the screen. Monitor quality is measured in terms of how many pixels, (“picture elements”) can be displayed per square inch. This is the monitor’s resolution. Most monitors are wider than taller.

Computer Hardware I/O ports - Connections on the back of a computer used to plug in peripherals. Common peripherals are printers, scanners, digital cameras, keyboards and mice.

Computer Hardware Connections are often color-coded, labeled and take the form of only a few different kinds of shapes. Usually, devices will not be able to fit together if the connection is not a good one.

Software Software refers to a set of instructions that tells the computer what to do. These instructions are also called Operating Systems or Programs Operating Systems – examples are Windows XP, Windows Vista. Programs – there are thousands of examples of programs. Games, office systems like Microsoft Office and PowerPoint, anti-virus software.

Bits and Bytes The computer really doesn’t understand any programming language. It is simply a machine. It is like asking if a hammer knows that it is building a house. The tool simply does what it is told to do. Computers “understand” the presence or absence of electricity. This is represented by binary numbers. Binary is a kind of mathematical system that uses only 1’s and 0’s