CS008 Midterm 2 Study Guide

-brain of a computer
-Control all functions performed by other components and process all the commands it receives
-Housed on the motherboard

Arithmetic Logic Unit
part of a processor that performs arithmetic calculations and logic comparisons

The part of the central processing unit that controls the flow of information through the processor.

Central Processing Unit
the brain of the computer.

fetch, decode,execute,store

an instruction retrieved by the main memory

the control unit translates the instruction into a computer command

The ALU processes the command

the results are written back to memory (stored)

speed at which the processor executes the cycles (measured in gigahertz → GHz)

consists of 2 or more processors that are integrated on a single chip

increases processing speed over single-core processors
reduces energy consumption over multiple separate processors

-a processor found on a video card which can contain multiple cores
-reduces the processing required of the system CPU for graphics-intensive processes

the process of using multiple processors (or multi-core processors) to divide up processing tasks → increase computer performance

-form of parallel processing
-a method used by a single processor to improve performance

the case that encloses and protects a computer's internal components

components that serve the input, output, and storage functions
Can be external devices or can be integrated into the system unit

main circuit board of a computer → provides ways for devices to attach to the computer

a wire on a motherboard over which info flows b/w components of a computer

an interface on a motherboard that expansion cards plug into

used to connect peripheral devices to motherboard
Most common is USB (universal serial bus)

they can be plugged in and unplugged w/o turning off the computer

a connection to a computer similar to USB or a parallel port that allows the rapid exchange of information between a computer and the device attached to it

developed by IBM and Apple
Thunderbolt 2 is standard on most Apple computers
Alternative to USB but not as popular
Hot-swappable

start up computer

stored on Rom
a non volatile form of memory

a small amount of very fast memory used to store frequently accessed information close to the processor

a form of removable storage and include CDs, DVDs, and Blu-ray discs
Uses laser beams to read data from discs → laser to either melt the disc material or change color of embedded dye)

a nonvolatile form of memory that can be electrically erased and programmed
Is non-mechanical
Resistant to shock b/c it has no moving parts and is very durable
Used in solid-state drives, flash drives, memory cards, and mobile devices

a small drive that uses flash memory to store data → used in small electronic devices like media players as well as notebooks and desktops → are small, fast, and light

a storage medium that uses flash memory to store data

the primary mass storage device in most computers b/c it is the cheapest form of storage

most common type of keyboard due to the way the letters are arranged

screen that accepts input from a finger or stylus (special pen-like input tool)

allow conversion of a photo or document into a digital file
Flatbed scanners are most common used in homes and offices

scans a QR code (ex = flight info can be scanned at the gate by flight attendant or movie/event tickets)

measure human characteristics like fingerprints and eye retinas → used in banks to identify patrons; theme parks to ensure that tickets aren't transferred to other guests

bigulky and use a lot of energy; were considered legacy technology (old technology that's still used alongside its more modern replacement b/c it still works and is cost-effective)

Sprays droplets of ink onto paper

most commonly used as a home printer

Uses pens to draw an image on a roll of paper used to produce very large printouts

Uses heat to turn solid dye into a gas that is then transferred to special paper

most commonly used in business → uses powdered ink that gives better quality printouts → a little more expensive but can be cheaper since ink cartridges don't need to be replaced that often → can print faster as well

Heats specially coated heat-sensitive paper, which changes color when heat is applied

Prints high-quality photos

used by individuals w/ disabilities to interact with technology (both hardware and software) → ex = braille input devices, voice/speech recognition devices

used to establish a connection with a network

process of optimizing RAM storage by borrowing hard drive space
A special file on the disk drive, called a swap file, is created.

provides user with the interface to communicate with the hardware and other software on the computer and manages system resources

part of the operating system that you see and interact with

enables you to point to and click on graphic objects such as icons and buttons to initiate commands
Newer type of UI
Easier to use than command-line

requires to type out all commands
Older type of UI

the ability to do more than one task at a time

A mode of operation that allows only one program to be in use at any time.

enables you to easily add new hardware to a computer system

acts as a translator, enhancing the capabilities of the operating system by enabling it to communicate with hardware

Application Programming Interface

allows the application to request services (ex = like printing or saving a file) from the operating system

Mac OS, Windows, Linux

1st true operating system version was Windows 95 (Windows is most commonly used operating system in the world)

1st commercial operating system to use GUI

Apple computers' primary operating system

a specialized operating system that runs on GPS devices, ATMs, smartphones and other devices

IOS, Android, Windows

Apple → scaled down version of Mac OSX

scaled down version Linux → open source so it's used on a lot of different phones and tablets (generally cheaper)

a network that has at least 1 server at its center → users log in to the network instead of their local computers and are granted access to resources based on that login

multiuser operating system that controls the software and hardware running on a network

windows, linux, unix

first released as windows NT in 1993

an open-source version of the UNIX operating system

Developed in 1991 by Linus Torvalds

Does not have a single version but many distributions (distr

The oldest NOS
all previous versions are based on UNIX

a network in which all computers are considered equal → each device can share its resources with every other device and there's no centralized authority

helps you maintain your computer and is also considered system software

Monitors health of files system on a disk

earranges fragmented files to improve efficiency

unorganized files that are broken into small pieces and stored in nonadjacent clusters on the disk

a disk utility that reorganizes fragmented files on a disk

looks for files that can be safely deleted to free up disk space so you can have more space to store your files and to help keep your system running efficiently

used to get info about the disks on your computer → verifies and repairs a disk
No need for disk cleanup

a device or software that blocks unauthorized access to a network or individual computer → both Windows and Mac have this but have to manually enable it on a Mac

a form of security software that protects against viruses, Trojan horses, worms, and spyware

the measure of the number of pixels in an image; expressed in megapixels

detailed/sharper image and larger file size

Most cameras store images internally or on removable memory cards that use flash storage

labeling images/files with keywords to make it easier to organize and search for them

tagging image with location information

JPEG, JPG, TIFF, BMP

uses lossy compression to reduce file size → most commonly used file type for webpages

used on windows

used on macs

some data is thrown away when file is compressed (done with images, audio, video)

no data thrown away when file is shrunk
For files that contain text and numbers

convert data signals into continuous electronic waves pulses → translate electronic pulses back into audio and video signals
Ex = telephones, CRT monitors

audio or video data is represented by a series of 0s and 1s → can carry more data and are less prone to interference than analog signals