Introduction to Computing

Hardware

&

Software

INSIDE THE COMPUTER

•Hardware•Physical components of the computer. Any part that you can see and touch •Examples: Boards, drives, monitor, keyboard, etc.

•Software•Virtual components of the computer. Exists as electrical impulses when the computer is on.•Examples: Windows, Word, Netscape, Excel, etc.

Hardware

•Motherboard•Main circuit board inside the computer. Contains the CPU and RAM among other things. All other hardware must maintain a physical connection to the motherboard. Body of the computer.

•CPU: Central processor unit. Computer chip in which instructions from the software are carried out. Measured in MHz-GHz (Megahertz-Gigahertz, millions/billions of operations per second). Brains of the computer. •RAM: Random access memory. Electronic memory in computer. Holds loaded software and any additional material created by currently running software while the computer is on. Measured in MB (megabytes). •IO Bus: Circuitry that moves information between the CPU and RAM. Measured in MHz. Usually significantly slower than CPU

Hardware

•Drives•Physical or permanent information storage (magnetic or optical in nature)•Hard drive, floppy, CD/DVD, Zip, etc.

•Other•Keyboard, mouse, monitor•Video, hard drive, network, modem, etc.

SOFTWARE

•Instructions for CPU•Written in the language of the computer (machine)

•Several layers of translation between user and computer•Loaded and stored in RAM when started•To perform a certain task (e.g. print a document), the CPU obtains the instructions from the program.•Removed from RAM when user quits/exits the program or computer is shut off•Memory management by programmer’s and user is critical

•The computer’s language•Digital (numerical) in nature•Binary (1’s and 0’s)

•Can also be thought of as a switch (on/off)…The “bit”

DIGITAL VERSUS ANALOG

•Analog•Nature is analog•Continuous•Non-numerical nature…must be translated to a numerical value.•Infinitely precise•Examples: Alcohol thermometer or old-style clock that requires winding

•Digital•Numerical by nature•Discreet levels•Less precise but generally more accurate than analog•Examples: Digital clock, Computers

DIGITAL VERSUS ANALOG(Sound Wave)

Analog sound wave

DIGITAL VERSUS ANALOG(Sound Wave)

Digital sound wave

DIGITAL IMAGES

•Formats (bitmap, gif, jpeg, and so on).

•Color of each pixel stored as a number.

•Memory intensive (compression algorithms).

Pixel: Smallest element of a screen or printer that can display a single color.