7/27/2019 remain-13.doc http://slidepdf.com/reader/full/remain-13doc 1/13 The speed of a printer is measured in: Cps - characters per second lpm - lines per minute ppm - pages per minute Print Quality A more numerical measure of print quality is printer resolution. Measured in dots per inch (dpi), this determines how smooth a diagonal line the printer can produce. Cable connection Serial cable- Sends data only 1 bit at a time Printer can be up to 1000 feet away from the computer. Maximum data transfer speed = ! "ilo#its$s (.!M#its$s) Parallel cable - Sends data 8 bits at a time Printer must be within 50 feet of the computer. Maximum data transfer speed% ! "ilo#ytes$s (.!M&'*$s). his is + times faster than the maximum serial speed. USB cable Printer must be within 5 meters 1!.5 feet" of the computer# when connecting straight to the computer. $%ou can hoo& up se'eral 5 m. cables and (S) hubs in a chain - up to *5 meters.+ Maximum data transfer speed% mega#its$s (.! M&'*$s) -ots faster
Transcript
7/27/2019 remain-13.doc
http://slidepdf.com/reader/full/remain-13doc 1/13
The speed of a printer is measured in:Cps - characters per secondlpm - lines per minuteppm - pages per minute
Print Quality
A more numerical measure of print quality is printer resolution. Measured in dots per
inch (dpi), this determines how smooth a diagonal line the printer can produce.
Cable connectionSerial cable - Sends data only 1 bit at a timePrinter can be up to 1000 feet away from the computer.
Maximum data transfer speed = ! "ilo#its$s (.!M#its$s)
Parallel cable - Sends data 8 bits at a timePrinter must be within 50 feet of the computer.
Maximum data transfer speed% ! "ilo#ytes$s (.!M&'*$s). his is + times faster
than the maximum serial speed.
USB cablePrinter must be within 5 meters 1!.5 feet" of the computer# when connecting straight to thecomputer.$%ou can hoo& up se'eral 5 m. cables and (S) hubs in a chain - up to *5 meters.+
Maximum data transfer speed% mega#its$s (.! M&'*$s) -ots faster
7/27/2019 remain-13.doc
http://slidepdf.com/reader/full/remain-13doc 2/13
Best choice:
he new /*& (/ni0ersal *erial &us) connection is li"ely your #est choice, if your printer
can use it. 1t is faster and a /*& connector can #e unplugged and re2plugged withoutturning off the system. /*& ports are gradually, #ut rapidly, replacing parallel ports. he
printer cannot handle the data as fast as the /*& port can
send it. he real limit on how fast a printer wor"s is in howfast printer can get the characters onto the paper.
cylindersThe formatting process sets up a method of assigning addressesto the different areas. ,t also sets up an area for &eeping thelist of addresses. ithout formatting there would be no way to &now what data went withwhat. ,t would be li&e a library where the pages were not in boo&s# but were scattered aroundon the shel'es and tables and floors. %oud ha'e a hard time getting a boo& together. /formatting method allows you to efficiently use the space while still being able to find things.
Tracks/ track is a circular ring on one side of the dis&. ach trac& has a number.The diagram shows trac&s.
Sectors/ disk sector is a wedge-shape piece of the dis&# shown in yellow. ach sector is numbered.2n a 534 dis& there are 40 trac&s with sectors each.2n a 64 dis& there are 80 trac&s with sectors each.
So a 64 dis& has twice as many named places on it as a 534 dis&.
/ track sector is the area of intersection of a trac& and a sector# shown in yellow.
Clusters
/ cluster is a set of trac& sectors# ranging from * to * or more# depending on the formattingscheme in use.
he most common formatting scheme for P3s sets the num#er of trac" sectors in acluster #ased on the capacity of the dis". A . gig hard dri0e will ha0e clusters twice as
large as a !44 M& hard dri0e.
7/27/2019 remain-13.doc
http://slidepdf.com/reader/full/remain-13doc 3/13
1 cluster is the minimum space used #y any read or write. *o there is often a lot of slack
space, unused space, in the cluster #eyond the data stored there.
Capacity of Disks
5¼" floppy - !0 7) or 1.* )
3½" floppy - 9*0 7) or 1. )
Hard diskearly ones
; *0 ) currently
arch *00"; 1*0< =)where 1 GB ;
1 iabyte ;10* ) future >>>1. seekmo'e the head to proper trac&seek timems"
*. rotaterotate dis& under the head to the correct sector
rotational delay ms"
. settlehead lowers to dis&?wait for 'ibrations from mo'ing to stopactually touches only on floppies"settlin time ms"
where ms stands for millisecond = .44 second and kbs is "ilo#ytes per second.
otal time to transfer a "ilo#yte%
for floppies#195 - 00 msfor hard dri'e#15 - 80 ms
new hard dri'es#@an. *000"
.456 ms (66.6 M&7 per sec).
"ensity Aigher density means more data on shorter tapeeasured as bpi ; bits per inch ranges from 800 bpi up to !*50 bpi"o#nloadin means to transfer a file to your computer !rom elsewhere.
Uploadin means to transfer a file !rom your computer to another.
$ast modi!ied: %hursday& 'uly (4& (00)The amount of data that can be transmitted in a fiBed amount of time. ,n digital
de'ices# the bandwidth is usually eBpressed in bits per secondbps" or bytes per second. Coranalog de'ices# the bandwidth is eBpressed in cycles per second# or AertD AD". )roadband isthe common term for a high bandwidth internet connection E one that can transmit ordownload information up to 0 times as fast as a standard telephone and modem. %ou can doe'erything you need to do online more Fuic&ly and more easily with broadband./ transmissionfacility ha'ing a bandwidth sufficient to carry multiple 'oice# 'ideo or data channelssimultaneously. ach channel occupies is modulated to" a different freFuency bandwidth onthe transmission medium and is demodulated to its original freFuency at the recei'ing end.
*ost popular +nternet Bro#ser/llorld Bplorer/2Gs 2riginal )rowser)rown,
"ata Glo,e / glo'e eFuipped with sensors that sense the mo'ements of the hand and interfaces
those mo'ements with a computer. Nata glo'es are commonly used in 'irtural realityen'ironments where the user sees an image of the data glo'e and can manipulate themo'ements of the 'irtual en'ironment using the glo'e.
$C" "ata Pro.ectorThe output de'ice which gi'es e'ery presenter a powerful tool to easily manage a
meeting. / de'ice for ta&ing the information from the computer and proOecting it onto to alarger mo'ie screen. The GIN and data proOectors that operates easily on a table top for fast#fool proof set ups which proOects wor& instead of displaying it on a monitor and can show a
7/27/2019 remain-13.doc
http://slidepdf.com/reader/full/remain-13doc 8/13
PowerPoint slide show# a eb page# or other proOects de'eloped on the computer to a largergroup of people.
*+"+ +/PU%These are used to produce music and are normal musical instruments which ha'e a midi portfor input into a midi interface in the computer. They often ha'e a wide range of special effectsor stored sound data from real instruments. The Specialised software allows the digitised musicdata to be stored as a file# displayed on screen and edited ready for playbac&. Se'eral methodsof recording are a'ailable: a simpli!ied input mode in which only note pitch is ta&en intoaccount# and a real-time input mode# in which all information about pitch# duration# 'elocity#channel etc is processed.
Sensors
These detect changes in the physical or chemical en'ironment and con'ert them intoelectrical signals. These signals can then be digitised and used by the computer. There are ahuge range of possible sensors and they include: heat? light? sound? mo'ement? magnetism?
pressure? strain? acidity pA"? oBygen le'els? liFuid le'els? humidity? pulse rates? salinity? waterflow? speed and acceleration.emote control
This emits a beam of infra-red light which carries digital data signals. They are oftenused to control TKs and KILs. ore ad'anced models can be programmed to transmit a seriesof commands with one button press. Their ad'antage is that each function can ha'e its ownbutton ma&ing them 'ery simple to use.
*ultimediaThe ultimedia means that computer information can be represented through audio#
'ideo# and animation in addition to traditional media i.e.# teBt# graphics drawings# images".*ultimedia is the field concerned with the computer-controlled integration of teBt# graphics#drawings# still and mo'ing images Kideo"# animation# audio# and any other media where e'ery
type of information can be represented# stored# transmitted and processed digitally.Characteristics o! a *ultimedia System
• ultimedia systems must be computer controlled.
• ultimedia systems are interated.
• The information they handle must be represented diitally.
• The interface to the final presentation of media is usually interacti,e.
.5 -inch floppy dis&*icrophone This is used for the input of sound which is then digitised by the computer. Koice
recognition software can be used to con'ert your 'oice into teBt or to control menu options.3+3%5 G6/6%+2/ C2*PU%6 S7S%6*S
The P,m-1 machine# one of the few 4fifth generation computers4 e'er produced. The fifth
generation computer systems proOect was an initiati'e by @apans inistry of ,nternationalTrade and ,ndustry# begun in 18*# to create a 4fifth generation computer which was supposedto perform much calculation utiliDing massi'e parallelism. The main aim of fifth generationcomputer systems is a disrupti'e technology.The Hew =eneration Iomputer Technology ,I2T"is creating a specialiDed hardware and an operating system entirely written in a 'ariant ofProlog programming language# as this was belie'ed to be a truly paralleliDable language. The4parallel inference machines4 were e'entually produced:
• P,m
• P,p
• P,i
• P,&
• P,c
Artificial Intelligence/rtificial ,ntelligence is a branch of Science which deals with helping machines find
solutions to compleB problems in a more human-li&e fashion. This generally in'ol'es borrowingcharacteristics from human intelligence# and applying them as algorithms in a computerfriendly way. / more or less fleBible or efficient approach can be ta&en depending on thereFuirements established# which influences how artificial the intelligent beha'iour appears.
/ fifth-generation programming language is a programming language or computerlanguage is a standardiDed communication techniFue for eBpressing instructions to a computer.,t is a set of syntactic and semantic rules used to define computer programs. / languageenables a programmer to precisely specify what data a computer will act upon# how these data
will be storedtransmitted# and precisely what actions to ta&e under 'arious circumstances.
Batch Operating Systems
arly computer systems only did one thing at a time. They had a list of instructions tocarry out - and these would be carried out# one after the other in serial manner. The computerwas wor&ing on batches of instructions the type of operating system was called a )atch2perating System. )atch operating systems are good to perform large numbers of repetiti'eOobs on large computers. g. Pay of each employee in large organisation? or processing all theFuestionnaire forms in a large sur'ey.
OPERATING SYSTEM TYPES
/s computers ha'e progressed and de'eloped so ha'e the types of operating systems.any computer 2perating Systems will fall into more than one of the below categories.=(, - Short for =raphical (ser ,nterface a =(, 2perating System contains graphics and icons andis commonly na'igated using by using a computer mouse. eBamples of =(, 2perating Systems.System 9.Bindows 8indows Iulti-user - / multi-user 2perating System allows for multiple users to use the same computerat the same time andor different times. ulti user 2perating systems are
GinuB(H,Rindows *000ultiprocessing - /n 2perating System capable of supporting and utiliDing more than onecomputer processor. )elow are some eBamples of multiprocessing 2perating Systems.
GinuB(H,Rindows *000ultitas&ing - /n 2perating systems that is capable of allowing multiple software processes tobe run at the same time. The multitas&ing 2perating Systems are follows.(H,Rindows *000
Sinle User 2peratin SystemCommand user +nter!ace9/ Single-user 2perating System allows for single user to use thecomputer at the same timeandor different times.N2S
odemsThe piece of eFuipment that allows a computer to communicate with other computers
o'er telephone lines is called a modem. / de'ice is needed to translate between the analogphone line and the digital computer. ,t modulates a digital signal from the computer into ananalog one to send data out o'er the phone line. Then for an incoming signal it demodulates
the analog signal into a digital one. he digital transmission is measured in bits per second(bps) 8 analog is measured in baud.
%ypes o! modem +nternal *odem:
This de'ice is a circuit board that plugs into one of the eBpansion slotsof the computer.,nternal modems usually are cheaper than eBternal modems# but when problems occur# fiBingand troubleshooting the modem can sometimes pro'e to be Fuite difficult. The telephone lineplugs into the modem port in the bac& of the computer.). Bternal odem:
This de'ice attaches to the bac& of the computer by way of a cable that plugs into themodem port. ,t is usually less eBpensi'e and 'ery portable. ,t can be used with other computers'ery easily by unplugging it and plugging it into another computer.C. Fax Modem: This de'ice can be hoo&ed up to your telephone and used to send
information to your computer. %our computer can also send information to a faB machine.ost computer modems are modems with faBing capabilities.
d. ISDN Modem:
The ,SNH modem reFuires a special phone line called an ,SNH line. This modem sends data at a'ery fast rate. 5!7". The ad'antage of this modem is that it is 'ery fast and is able to transferdata and graphics at an amaDing speed with 'ery little interference. These modems and linestend to be Fuite eBpensi'e.
,HTLC/IThe type of interface is also important. There are generally only fi'e choices. Proprietary lesscommon today"# Serial# Parallel# SIS,# or (S)..
Proprietary - This is the strangest and most difficult. ,t could be a mutated 'ersion of aserial# ,N# or SIS, controller. These proprietary controllers are usually built into sound cardsto control IN L2 dri'es# or bundled with tape dri'es.4 They ha'e been mostly discontinuedsince 1!.
Serial - =enerally your mouse is either on Iom1 ,LM " or the PS* port ,LM 1*" and amodem often o'er-rides Iom* ,LM "... adding additional Iom ports is possible
Parallel - Today motherboards has high speed printer ports IP ; nhancedIapabilities Port# and PP ; nhanced Parallel Port" which transfer data faster and better.Parallel scanners# Aard dri'es# Tape dri'es# IN L2S# Qip dri'es# and a few other de'ices arenow feasible to run through the printer port without any maOor delays or problems. ,t is alsopossible to 4chain4 multiple de'ices up to 9" in a row off the parallel port.
SIS, - This is a special card in your computer possibly built-in on 'ery high-end
motherboards". There are three 4common4 types: 1# *# and . The ad'antage of SIS,-1 J *de'ices is that you can run up to 9 de'ices off 2H controller# and it was specifically designedfor multi-tas&ing# networ&s# and huge files. Iommonly used for high-end scanners and eBternaldri'es hard dri'es# Qip# @aD# Sys@et# SyMuest# Babyte# cd# cdr# cdrw# tape# etc.".
SIS,-1 is usually 8bit# and has a maB speed of 5) per second transfer with optimumconfiguration.SIS,-* is 1! bit minimum# sometimes * bit KG) Kesa Gocal )us" or PI,. The SIS,-* cards ha'e amaBimum transfer rate of *0) per second# with 10 to 15) a'erage.
SIS,- is a little different - is usually * bit. ,t is !8 pins# capable of 0) per second sustainedtransfer PL NK,I# and up to 15 de'ices on one controller.(S) - Aailed as the latest and greatest type of ports a'ailable# with up to ! de'icessupposedly being able to be daisy chained off each port and speeds in the 1*) per secondrange and automatic dri'er installation 'ia firmware.
