Chapter 2 Flashcards
What are the components of a typical computer system?
System unit and peripheral devices (keyboard, nouse, hard disc drive, optical drive, removable storage, sound system, display system, network and internet access, printer)
Desktop Computer
Fits on a desk and runs on power from an electrical wall outlet
Peripheral device
Input, output, and storage equipment that might be added to a computer system to enhance its functionality
System unit
The case that holds the computer’s main circuit boards, microprocessor, memory, power supply, and storage devices
What is the significance of different computer designs?
The form, such as size and dimensions, of a computer must suit the function that it will be used for
What are the options for desktop computer form factors?
Horizontal, vertical, all-in-one
Tower case
Provides space for those who want to enhance or upgrade their machines
All-in-one computer
The computer circuitry is incorporated in the back of a flat-panel screen
How do portable computers differ from desktops?
Desktop computers run on power from an electrical wall outlet, while portable computers can run on an outlet or battery and are easy to carry around
Portable computer
A small, light-weight personal computer with input, output, storage, and processing components integrated into a single unit that runs on power supplied by an electrical outlet or battery (clamshell or slate)
What is a laptop computer?
A small, light-weight portable computer that opens like a clamshell to reveal a screen and keyboard
What types of computers are available in the slate form factor?
Enhanced media players, smartphones, tablets
What is an enhanced media player?
A handheld device designed for playing music and videos
What is a smartphone?
An enhanced mobile phone that also functions as a portable media player and has the capability to access the Internet
What is a tablet computer?
A handheld computer that is essentially a large version of an enhanced media player
What is compatibility?
Computers that operate in essentially the same way and use the same software
What are the three popular platforms?
PC, Mac, Linux
What’s the significance of designations, such as home, small business, or game systems?
Created by computer vendors to help consumers sort through the variety of configuration options
What differentiates a home computer from other types?
Encompasses a vast array of desktop and laptop computer configurations designed to accommodate computers who use computers for personal tasks
What’s so great about a gaming computer?
Feature the fastest processors, stuffed with memory, state-of-the-art sound capabilities, and multiple graphics processors
What are the characteristics of small business computers?
A medium-speed processor, moderate amount of RAM, sensible disk capacity.
What is a microprocessor and what does it look like?
An integrated circuit designed to process instructions; largest chip on the system board, could be hidden under a cooling fan
What makes one microprocessor perform better than another?
Clock speed, bus speed, word size, cache size, instruction set, number of cores, and processing techniques
What do MHz and GHz have to do with computer performance?
Indicates the speed of the microprocessor clock, a timing device that sets the pace for executing instructions. GHz means a billion cycles/second.
What’s a multi-core processor?
A microprocessor that contain circuitry for more than one processing unit
What is FSB?
FSB stands for front side bus, a term that refers to the circuity that transports data to and from the microprocessor. Measured in MHz (million cycles/s)
How does the cache size affect performance?
Three levels: 1 is fastest, 2 and 3 are slightly slower
CPU cache
Special high-speed memory that allows a microprocessor to access data more rapidly than from memory located elsewhere on the system board
What impact does word size have on performance?
Based on the size of the registers in the ALU and the capacity of circuits that lead to those registers
Example: A 64-bit processor has 64-bit registers and processes 64 bits at a time
Word size
The number of bits that a microprocessor can manipulate at one time
How does an instruction set affect performance?
A RISC processor performs most instructions faster than a CISC processor, but may require more of these simple instructions to complete a task than a CISC processor
CISC
Complex instruction set computer; used by microprocessor with increasingly complex instructions
RISC
Reduced instruction set computer; used by microprocessor with a limited set of simple instructions
Can a microprocessor execute more than one instruction at a time?
Yes, in pipelining and parallel processing, but not serial processing.
Serial processing
The processor must complete all steps in the instruction cycle before it begins to execute the next instruction
Pipelining
A processor can begin executing an instruction before it completes the previous instruction
Parallel processing
Multiple instructions are executed at the same time
How can I compare microprocessor performance?
Benchmarks are the results of a series of tests to gauge the overall speed of a microprocessor, which can be compared to the benchmarks of other microprocessors
What do the Windows Experience Index scores mean?
The performance subscores for five computer components. Base score determined by lowest subscore.
What is overclocking?
A risky technique for increasing the speed of a computer component
What is RAM?
Random access memory; a temporary holding area for data, application program instructions, and the operating system
Why is RAM so important?
Holds raw data waiting to be processed, results of processing, and operating system instructions
How does RAM work?
Most ram is volatile, it needs electrical power to hold data. In RAM, microscopic electronic parts called capacitors hold the bits that represent data.
Virtual memory
If a program exceeds its allocated space, the operating system uses this area of the hard disc to store parts of programs of data files until they are needed
How do I add RAM?
SDRAM is the most popular type of RAM in today’s computers and is sold as a small circuit board
What is ROM?
Read only memory; a type of memory circuitry that is housed in a single integrated unit. ROM is permanent and nonvolatile.
What is EEPROM?
Electrically erasable programmable read only memory
What does a computer store in ROM?
Contains a small amount of instructions called the bootstrap loader; Sometimes referred to as BIOS (basic input/output system) in a PC
What are the basic components of a data storage system?
A storage medium and a storage device
Storage medium
The disk, tape, CD, DVD, paper, or other substance that contains data
Storage device
The mechanical apparatus that records and retrieves data from a storage medium
How does a storage device interact with other computer components?
Data gets copied from a storage device into RAM, where it waits to be processed. It it then held temporarily in RAM and usually copied to a storage medium for more permanent safekeeping
What are the three types of storage technologies?
Magnetic, optical, and solid state
How can storage technology be compared?
Based on versatility, durability, speed, and capacity
What factors affect storage speed?
Access time and data transfer rate
Access time
The average time it takes a computer to locate data on the storage medium and read it (milliseconds)
Random access
The ability of a device to “jump” directly to the requested data (CD, DVD, Blu-ray)
Sequential access
Reads though data from the beginning of the tape (cassette tape)
Data transfer rate
The amount of data a storage device can move per second from the storage medium to the computer
What’s so important about storage capacity?
Today, higher capacity is almost always preferred, so it is important to consider storage capacity and density
Storage capacity
Maximum amount of data that can be stored on a storage medium, measured in bytes
Storage density
The amount of data that can be stored in a given area of a storage medium, such as the surface of a disk
What is magnetic storage technology?
Stores data by magnetizing microscopic particles on a disk or tape surface
How does a hard disk drive work?
A hard disk drive contains one or more platters and their associated read-write heads.
Hard disc platter
A flat, rigid disk made of aluminum or glass and coated with magnetic iron oxide particles
Read-write head
A mechanism in the disk drive that magnetizes particles to write data, and senses the particles’ polarities to read data
Why are hard disk drives so popular?
Provides lots of storage capacity , fast access to files, and is economical
What’s the downside of hard disk storage?
Not as durable, data stored on magnetic media can be unintentionally altered
Head crash
When a read-write head runs into a contaminant on the disk that damages the data on the disk
CD
(compact disc) Capacity of 80 minutes of music or 700 MB of data
DVD
(digital video disc) Contains two recordable layers on the same side and can store 8.5 GB of data
Blu-ray
A high-capacity storage technology with a 25 GB capacity per layer
How do CD, DVD, and Blu-ray drives work?
These three are classified as optical storage, which stores data as microscopic light (lands) and dark (pits) spots on the disc surface and contains a spindle that rotates the disc over a laser lends, translating the differences in light to data
What’s the significance of ROM, R, and RW?
Read-only technology: stores data permanently on a disc that cannot be added to or changed
Recordable technology: uses a layer to change the color in a dye which cannot be changed once data has been recorded
Rewritable technology: the crystal structure allows data to be recorded and modified over and over again
What is solid state storage capacity?
A technology that stores data in erasable, rewritable circuitry, rarther than on spinning disks or streaming tape
How does solid state storage work?
Contains a gridwork of circuitry, each cell containing two transistors that act as gates to hold the 1s and 0s that represent data. This data is non-volatile, very durable, but is more expensive than magnetic and optical
What are my options for solid state storage?
Memory cards, solid state drives, USB flash drives
When should I use memory cards?
A memory care is a flat, solid state storage medium commonly used to transfer files from digital cameras and media players to computers
Card reader
A device that reads and writes data on solid state storage
Solid state drive
A package of flash memory that can be used as a substitute for a hard disk drive and is usually used for customers who use computers in rugged conditions
USB flash drive
A potable storage device that plugs directly into a computer’s system unit using a built-in connector
Can I add storage to my computer?
You can increase storage capacity by adding hard drives and can add storage flexibility by installing additional types of storage devices, such as an external drive or drive bays
Drive bays
Drive bays, external or internal, are parking spaces for storage devices inside a desktop or laptop system unit case
What devices can I use to get data into a computer?
Keyboard, mouse, touch-sensitive screens, scanners, digital cameras, graphic tablets, microphones, and electronic instruments
What does a pointing device do?
A pointing device allows you to manipulate an on-screen pointer and other screen-based graphical controls
Which pointing device should I choose?
Desktop computer systems usually use a mouse, while game controllers come in styles such as joysticks, steering wheels, and wands
When do I need a trackpad?
A trackpad is a touch-sensitive service on which you can slide your fingers to move the on-screen pointer
How does a touchscreen work?
A touchscreen is a transparent panel coated with a thin layer of electrically conductive material that senses a change in the electrical current when touched
What are my options for display devices?
LCD: (liquid crystal display) produces an image by filtering light though a layer of liquid crystal cells; advantages include display clarity, low radiation emission, portability, and compactness
LED: (light-emitting diode technology) A gradual replacement for the harmful CCFL backlighting of LCD technology
What factors affect image quality?
Screen size, dot pitch, width of viewing angle, response rate, resolution, and color depth
Screen size
Measurement in inches from one corner of the screen diagonally across to the opposite corner
Dot pitch
Distance in millimeters between like-colored pixels; Measure of image clarity
Pixels
The small dots of light that form an image
Viewing angle width
Indicates how far to the side you can still see clearly see the screen image
Response rate
The time it takes for one pixel to change from black to white then back to black
Color depth
The number of colors a monitor can display
Screen resolution
The number of horizontal and vertical pixels that a device displays on the screen (standard 4:3, widescreen 16:9)
Should I set my computer on its highest resolution?
At higher resolutions, text and other objects appear smaller, but the computer can display a larger work area
What are the components of a typical computer display system?
Display device and graphics circuitry, such as integrated graphics or dedicated graphics
Integrated graphics vs. dedicated graphics
Integrated in built into a computer’s system board, which dedicated is graphics circuitry mounted on a small circuit board called a graphics card
Graphics card
A small circuit board that plugs into the system board
Graphics processing unit (GPU)
Contained in a graphics card along with special video memory, which stores screen images as they are processed but before they are displayed
How does an ink jet printer work?
Has a nozzle-like print head that sprays ink onto paper to form characters and graphics
How do laser printers compare to ink jet printers?
Uses the same technology as a photocopier to paint dots of light on a light-sensitive drum
What is a dot matrix printer?
Produces character and graphics by using a grid of fine wires
What features should I look for in a printer?
Resolution, print speed, duty cycle, operating costs, dulex capability, memory, networkability
Resolution
The quality of sharpness of printed images and text
Print speed
Measured by pages per minute or characters per second
Duty cycle
Determines how many pages a printer is able to churn out
Operating costs
Include ink cartridges, toner cartridges, or replacement ribbons
Dulex capability
Can print on both sides of the paper
Memory
Data that arrives at a printer along with its printer language requires memory
Networkability
Can connect directly to a computer network, rather than to a single computer
Printer Command Language vs. Postscript
PCL is the most widely used language for communication between computers and printers, but Postscript is an alternative printer language that many publishing professionals prefer
How does a computer move data to and from peripheral devices?
Data travels from one component to another over circuits called a data bus. Local or internal bus runs between RAM and microprocessor, which expansion or external bus connects to peripheral devices
Expansion slot and card
A long, narrow socket on the system board into which you can plug an expansion card, which is a small circuit board that gives a computer the capability to control a storage, input, or output device
What is an expansion port?
Any connector that passes data into and out of a computer or peripheral device
Is it difficult to install a new peripheral device?
No, most peripheral devices connect to a USB port located on the computer system unit
What if I run out of USB ports?
You can easily add USB ports to your computer by using a USB hub
When do I use other kinds of ports?
- FireWire ports are used for external storage devices and for transferring data from digital video cameras to a computer
- eSATA is a high-speed port used for connecting external storage devices
- Thunderbolt is a very high-speed port for connecting display or storage devices
- VGA, DVI, and HDMI are designed for audiovisual devices
What is hot-plugging?
When you connect or disconnect a peripheral device while the computer is operating; This is allowed with USB and FireWire devices
How do computer anti-theft devices work?
Kensington Security Slot is a small, reinforced oblong hole into which you can insert a special lock that can be attached to a cable
If my computer is stolen, can authorities recover it?
Yes, if you have taken measures such as recording the computer’s serial number, affixing a tracking label, or installing tracking software
What is a power surge?
A sudden increase in electrical energy affecting the current that flows to electrical outlets
How can I protect my computer from power surges?
By plugging computer equipment into a surge strip instead of a wall outlet
What is a surge strip?
A device that contains electrical outlets protected by circuitry that blocks surges
What is a UPS?
Uninterruptible power supply; provides surge protection and furnishes desktop computers and network devices with battery backup power during a power outage
What is the blue screen of death?
An indication that the operating system has encountered an error from which it cannot recover, and the computer no longer accepts any commands
What is safe mode/Safe Boot?
Designed for professional troubleshooting; Can be used to track down and uninstall programs or hardware that might be causing operational problems
