info tech mid term
most important category of data processing system
equally important
spoofing
fake email addresses that seem to be from a known source
advantage of RAM over auxiliary storage
faster access speed
function of operating system
file managment, user interface, data security, I/O managment
forms of magnetic disks
floppy disks and hard disks
output batch proc
forming charectors in a printer- dot matrix. charector printed on page, hammer striking.
what calculates values in a spreadsheet
formulas
clock rate
frequency of pulses, determines how often work can be done
uploading direction
from local computer to a remote computer
downloading direction
from one remote computer to the local computer
batch proc
gathers data over period of time, puts into machine readable format nd proc data as group, 3 phases= data entry(when captured nd put in file), proccessing
system clock
generates pulses in cpu, no proc done until pulse
what is an end-user agreement
gives a user the right to use a program, but not to sell or modify it
what is the data path(bus width)
group of bits that are transmitted at the same time
what is a computer word
group of bits that makes memory location, or the group of bits that are processed at the same time
byte
group of bits that represent a charector, 8 bits, storage measured by bytes
data path
group of bits thats transferred at one time. decreases rep power since requires two or more operations to move
system
group of components that work together to accomplish a function
microcomputer
handles single user. desktops, laptops, palmtops. smnallest
two levels of computer systems
hardware and subcategories
categories of a data processing system
hardware, software, data, personnel, procedure
density on tape
how close together data is recorded, bits per inch
domain experts
human experts in an expert system
URL
identifies web page
parity
in magnetic tape, errors may ocur, parity bits are bits added to detect these errors, odd parity = if even number after oarity bit error. even = oppasite of odd. zero parity = no way to detect error. clear parity = parity bit set to zero, mark parity = parity set to one
sector
in sector organization, each surface on disk is split into sectors each sector has a number and is on each surface of magnetic disk,
track- direct
in sector organization, each track on surface of each sector, with a track number,
expert system
info system that captures and stores the knowledge of human experts nd imitates human behavior
world wide web
information base on internet that connects documents to others allowing for surfing
CPU
initiates and controls all activity in system, contains circuitry that does basic operations, two major parts are control unit and arithmetic/logic unit
how is info accessed
though its stored in files but accessed in records
latency time
time for sector to rotate under the read/ write head.
transfer time
time to move data
seek time
time to move to correct track
IP address
to send messages to a device need IP add
storage capacity
total amount of storage a device has
uploading and downloading
transfering info
optical disk
uses light instead of magnets, data recorded as light and dark spots. greator storage density, lasts longer, but most cant be erased and reused and slower access speed.
binary device
uses only two discrete codes. most computers
decimal devices
uses ten descrete codes
input equipment
way data is entered into system to be proc
URL
web addrress
search engines
web sites that allow you to look for pages
volatility
when loss of power, all data is lost
word wrap
when right margin is reached the txt goes to the next line automatically
connections
wifi, dial up(public facility connection), cable, satelite, etc
proccessing power determined by
word size and clock rate
what 2 things determine processing power
word size and clock rate
hard disk
built into computer, greater storage density, faster access speed.
E-commerce
buissness activity online, B2B= buissness to buissness, B2C= to consumer, C2C= consumer 2 consumer
surfing
moving from one website to another
home page
1st page displayed when website opened
mainframe
20-100 users, also called server.
minicomputer,
2nd smallest. 4-10 users, not popular
most important component of computer systems
CPU
what do you need to process info
CPU AND RAM
subcategories of the computer system
CPU/RAM, input equipment, output equipment, auxiliary storage, other peripheals
interactive proc output
CRT monitors= glass tube like tv set, redraw image, resolution, format image. raster pattern = move beam in constant pattern nd only turn on for dots.
aux storage vs RAM
RAM isexpensive, limited sizevolatile, but faster than aux. auxillary is cheap, unlimited in size, non-volatile
cylinder organization
SET OF ALL TRACKS ON ALL SURFACES AT A PARTICULAR POSITION,tracks are circles that start in the middle of disk to end each with dif amount of data. each cylinder has a "cylinder number" this is the same as the track number on the surface. track number. also need offset(address in bytes)
binary vs decimal
binary faster, simpler, cheaper.
smallest unit of info storage
bit
importing
bringing data from a different program into the current one and putting it into the form used by it.
what is memory called that gives each byte an address
a byte addressable memory
main memory RAM, and addresses
access memory in any order, we need an address to specify what we want though. these are bit-addressable, or byte-addressable, or word-addressable. most byte
spyware
adware or pop up generators, browser hijackers, key loggers.
storage density
amnt data stored in a given area
plug-in
an applet that is added to a BROWSER improves browser like opening files
what device represents values as continuous physical measurments
analog device
web portal
anchor site that connects a variety of resources
phishing
attempt to have user provide personal info email
comercial input devices
bar code scanners, light wands, etc.
ways to input data
batch proc and interactive proc
output proc types
batch proc and interactive proc too, but in dif way
why are the main memory(RAM) and the CPU in the same category
because they work together, CPU processes but doesn't store and main memory stores but doesnt process
transmission speed
best way to get message through over the internet in noisy enviro . slow
blocking records
between each item it writes, the drive stops. there is a gap here. blocking records reduce amount of space used by gaps.
how is data represented
binary digits/bits
voice band
capacity of telaphone line
batch processing data entry equip used to make file
card punch, key to tape, key to disk
batch input equip
card reader, tape drive, disk drive
whats a spreadsheet called
cell
track-cylinder organization
circular on disk starts in middle and each track goes to the end of the disk and has dif amnts of data.
web sites
collected of related web pages
wideband
computer to computer connection speed measurmemt
network access point
connection for the ISP to the internet
how internet works
connects thousends of usually private networks and computers to internet
two major parts of CPU
control unit, arithmetic logic unit
disk organization
coordinate system helps maintain direct access of records.
what does word processing software do
creates, edits, formats, prints, and saves txt docs
two types of disk organization
cylinder and sector
sequential access
data accessed in order first to last, economical but speed to get to a particular record slow. if data proc in order, access better
interactive processing
data entered directly proc immedietely.
what device has ten different states
decimal device
size of computer
determined by number of users they typically handle
node
device connected to network
client
device that uses service of the net work
analog vs digital device
digital is more flexible but some values cant be represented but values can be cleaned up/fixed, analog values cannot be corrected but they can all be displayed
difference in uploading and downloading
direction
web page
docs that contain info on the web /HTML/HTTP
selecting printer factors
draft quality, letter quality, near-letter quality, laser quality,
cylinder in cylinder organization
each cylinder is a group of tracks which are in the same position but on another surface.
sector organization
each surface divided into sectors, each track on the surface of each sector, data is not always at the beginning of each sector
gap between written items on tape
inter-block gap
instant message (IM)
interacts with a message server wich sends message directly to comp
name the parts of an expert system
knowledge base and inference rules
parts of expert system
knowledge base, inference engine uses info from kno base to produce conclusions, user interface allows user to ask questions.
two considerations for buying mobile computer
large screen, light weight, proccessor, memory and storage.
what can make processing power bigger
larger word size means greater rep power means greater proc power
name operating system other than any windows
linux
booting
loading operating system into RAM on startup.
point of presence(POP)
local connection provided by ISP(internet service provider)
system software does
makes the hardware work, or work better
pharming
malicious software sends user an imposter site with correct URL
word size
maximum number of bits a CPU can process in a given time/ determines how much work can be done
bandwidth
measure how much data can be sent in a given amount of time. bits per sec
most connections require the use of a
modern, this is a modulator which changes the signal from one form to another digital to analog.
data in sector
not always at begining, needs offset(address given in bytes),
blocking factor
number of records per block(group of records)
window
on browser, web page is displayed. windows split into sections called frames
represational power
one bit reps 2 things. to rep more need more bit. rep power is the number of things that can be represented
magnetic tape
only form of sequential device. most useful for storing large amounts, backup, and archiving.
snooping
others see and read your email
what is a use of computers in healthcare
patient records
knowledge engineers
people who create expert system
display adapter(interactive output prc)
performs graphics processing. types = MDA,CGA,EGA,VGA,XGA,sVGA.
tracks(on magnetic tape)
position which a bit is recorded(across width of tape)
browser
program that displays web pages, gives us access to internet
browsers
program that interprets the URL's, pages have connections to other pages called hyperlinks
productivity applications
programs that helps a user do their jobs faster
service providers
provide connection to the internet
comercial online servers
provide internet conect, and other content
server
provides some service to other nodes on the network
bandwidth
range of frequencies that make communication channel OR data that can be TRANSFERRED in a amnt of time
how does blocking records reduce gap size
read and writes groups of records instead of one ata time, only need gap between groups of records,
when data is accessed, what unit is accessed
record
floppy disks
recording medium flexible plastic, REMOVABLE, cant maintain constant gap, so read/write head on surface
direct access
records accessed directly, MAGNETIC DISKS disk organization makes finding records possible. less economical.
in floppy disks, r/w head on surface because
reduce friction which would slow down rate of rotation, and so r/w head can be larger
data
representation of information
digital device
represents values by discrete code
wireless internet service providers
same as internet service providers but wireless
hard disk access speed components
seek time, latency time, and transfer time
output batch proc interface
serial, transfers bits of the byte one after the other, slower nd cheaper/parallel= eight bytes at a time,/
backbone
set of high speed lines that connect gateways of a network in any network
field
set of related bytes that stores one facts. has data type (the values it can take) and field length(amount of data in the field)
record
set of related fields. facts that pertain to one thing
database
set of related files. has dat, and data about the data(metadata).
file
set of related records, all records pertaining to something, like students
virtual reality
simulator mimic some physical or abstract systems
device driver
small program that allows the operating system to control actions of peripheal device
cookies
small text files such as passwords saved by websites
malware
software intended to cause harm to a comp system
shareware
software that can be obtained for free for trial period but then requires payment
input ex
sound input = microphone, image= scanner, digital camera,
forms of output
sound=speakers, images=pics and vids, direct control = computer directly controls some equipment,
art intel, natural language processing
study intended to allow computers to recognize understand and produce human language
fastest most powerful computer
supercomputer
expert systems
systems that mimic the action of human experts.
information technology
systems, software, and devices that create, share, and manipulate info
atrificial intelligance
tech that emulate human activities. export or knowledge based systems
interactive proc data enrty equip
text from keyboard, mouse, trackball, pointer, touch pad, touch screen, joy stick, light pen.
processing power
the amount of calculations that can be done in an amnt of time