HARDWARE Flashcards
what is hardware
physical components of computer categorised into input,processing, output, storage,communication
IPO
input process output
principle followed by computer
motherboard
large printed circuit board (PCB) that houses essential electrical components of device
main component of computer
capabilities of device dictated by motherboard
CPU,RAM and connectors and peripherals all linked to motherboard
how do you extend the capabilities of the motherboard
bus slots
(eg graphic card,sound card)
CPU
central processing unit
largest chip on computer
interprets and executes demands
divided into ALU,CU,Registers
von Neumann architecture
design of the CPU in relation to secondary storage and RAM
programs stored permanently in secondary storage.
in order for program to run, it must be loaded into RAM,as CPU is directly connected to RAM
ALU
arithmetic logical unit
performs logical calculations and simple arithmetic or integer binary numbers
CU
control unit
co-ordinater
sends control signals and instructions to be processed
instructs the memory, logic unit, and both output and input devices of the computer on how to respond to the program’s instructions.
Registers
small memory slots that store instructions CPU is currently processing
BIOS
basic input output system
non volatile firmware
initialise hardware when computer starts up so OS can take over and use hardware afterwards
programmed on ROM chip
RAM
random access memory
primary memory
form of storage that holds data currently being processed
needs power to retain memory
volatile
volatile
unpredictable, dynamic
contents constantly changing during processing and lost when computer switched off
DRAM
dynamic random access memory
constantly needs to be refreshed otherwise all contents will be lost
ROM
read only memory
non volatile
stores list of instructions device needs to run
non volatile
permanent
firmware
set of instructions programmed on a hardware device
semi permanent
typically stored in flash rom
peripherals
connected to the motherboard- not directly placed on
components
placed directly on motherboard
secondary storage
permanent , non volatile storage
can be fixed or removable media
hard drives
stores all users programs and data permanently
housed inside computer case
HDD
mechanical hard disk drive
designed with
mechanical read/write head that scans disk for data represented magnetically
vacuum sealed (to protect from dust)
data represented/stored magnetically
SSD
solid state drives (SSD)
electronic circuits
info stored in microchips- faster and less susceptible to shock or damage
can be internal or external
hybrid drives
benefits of HDD and SSD conbined
high storage and speed, cost benefits
flash drives
small portable storage device that uses SSD technology
connect via USB port
useful for transferring and backing up data
optical drives
laser burns data onto a disc
lost popularity to flash drives-cannot change data
CD,DVD,Blu-ray drives
SD cards
secure digital cards
high memory for small size
used in portable devices
provide 16GB upwards capacities
input devices
hardware that gets data into computer
data stored in RAM
keyboard
many keys that represent characters w/ unique value
typing keys
numeric keypad
function keys
control keys
layout - QWERTY
mouse
pointing device used to select and click on icons
detects change in position and makes similar change on screen
optical mice-use Light Emitting Diode that bounces light off mouse pad surface
wireless mice- receiver receives signals transmitted from mouse
scanners
analyse image and convert it to file
Optical Character Recognition OCR- analyse image w text and convert text to unicode to be altered and edited
scanner resolution
measured in dots per inch (pdi)
the better the scanner,the higher the resolution
barcode scanners
scan prices at Point of Sale (POS) terminals
barcode stores info abt product
scanner shines red LED light onto barcode pattern and reads pattern of reflected light
barcode
pattern of thin and wide lines that represent data
Laser light is shone on the label surface and its reflection is captured by a sensor (laser photo detector) to read a bar code
QR codes
Quick Response codes
easily read by camera of smartphone
2 dimensional sets of diff sized squares on white background
contain more info than barcodes
magnetic stripe readers
info encoded on magnetic stripe of card
converts info into format that computer can understand
biometric devices
recognise individuals by unique physical characteristics
captured,converted to digital format and represented mathematically
compare stored data against inputted data
(fingerprints, retina scans,voice prints)
quick,high level of accuracy
microphones
convert sound energy into electrical/digital energy
use diaphragm to sense sound wave and convert into electrical signal
sensors
convert physical property into data-made into signal to be measured electrically
(position,height,speed,temperature,location)
used in smart homes,alarms,autopilot systems
accelerometer
sensor that gauges tilting and orientation of smart phone to determine which orientation phone must show
output devices
hardware device that receives information from computer
monitors
screen that displays information in pictorial or textual form
resolution and screen size important factors
most commonly used monitors
Liquid Crystal Display (LCD) screens
resolution
number of pixels across and number of pixels down on monitor
the larger the screen the higher the resolution
touch screen
used in smartphones, tablets and laptops
input and output device
finger used as pointing device
printers
laser and inkjet technologies
print in black and colour or only black
non impact printers - nothing touches paper besides ink/toner
impact printer- old dot matrix-hammer touches ribbon on paper
3D printers - allow user to design object and create it
3D printing process
object designed
whole object turned into little slices (slicing)
and created from bottom up , slice by slice
speakers
receive audio input (in digital form) from sound card and produce audio output in form of sound waves
have internal amplifier- increase volume/amplitude
come in pairs- stereo sound from 2 separate audio channels
headphones
use diaphragm to convert digital data into sound waves
headsets - combo of headphones and microphone- speak and listen simultaneously
ports
allow for communication w/ device that is appropriate to send/receive correct data
versatile and universal ports HDMI and USB- reduce no. of ports needed
USB
universal serial bus port
common interface that enables communication between devices and host controller
wide variety of uses
mice,keyboards,digital cameras,printers,scanners,media devices,external hard drives,flash drives
replaced parallel +serial port
HDMI
high definition multimedia interface
port
provide digital interface to receive + transmit video and audio signals
tapered edges
replaced VGA and sound jack port
modularity
computer comes in separate components that you can piece together w your requirements in mind
- easy to repair - remove offending component + replace
- flexible - can add components to motherboard depending on needs
-able to upgrade- simplifies upgrading with better hardware
