CSEC Theory Exam 97 - 2002 Answers

7/30/2019 CSEC Theory Exam 97 - 2002 Answers

1/25

CXC Information Technology

Theory

Past Papers 1997 - 2002

ANSWERS

CONTENTS

Exam Answers Page

1997 ............................................................................................. 2

1998 ............................................................................................. 5

1999.............................................................................................. 7

2000.............................................................................................. 102001 ............................................................................................. 14

2002 ............................................................................................. 17

2002 specimen ............................................................................. 21

To go to any specific page number, press Ctrl and G on your keyboard, next type in thepage number then clickGo To. Close the Go To box.

Ctrl Home takes you to the beginning. Ctrl End takes you to the end.

To view the Questions open the Past Papers file. Have them both open at the desired pages

and switch from one to the next by clicking on the file name on your task bar.(usually at

the bottom of your screen)

1


2/25

Information Technology Theory (1997) Answers

1 (a) Printer, plotter or monitor (b) Hard drive, or diskette drive or tape drive(c) Optical Character Reader (OCR) or scanner

2 (i) joystick(ii) point of sale terminal(iii) optical mark reader(iv) scanner

3 (a) 10100112(b) 205(C) 1100102(b) Discrete data is data which can be counted and continuous data cannot be counted but must be measured.

4 (a) Computer Assisted Learning, storing students records and sourcing teaching

material.

(b) Preparing articles and researching articles.

(c) (i) Systems Analyst : determines systems requirements(ii) Systems Designer : designs blue print for software and hardware(iii) Programmer : develops programs in accordance with requirements(iv) Systems Programmer ; ensures systems environment for running programs

is functioning properly

5 (a) A valid description for example: A robotic arm is used in the automobile industry toweld component parts together.

(b) reduces employee risk and lowers operating costs.(c) eliminates transportation costs(d) difficult to assess quality of items

(e) Advantage : participants are not inconvenienced by commuting

Disadvantage : participants cannot utilize a full range of interpersonal

communication skills

6 (a) A program represents the work of an individual and unauthorized use of the workis essentially using the property of another person without his or her permission.

(b) Sensitive data can be viewed by all persons and unauthorized changes can bemade to the data.

(c) data encryption is the use of secret procedures for coding and decoding information

(d) use of passwords and fireproof cabinets(e) An application programmer develops programs to be used by general users and systems

2


3/25

programmer prepares the operating systems environment for the application program to run.

7 (a) Protocol is the set of rules and procedures to govern the transmission of data.

(b)(i) Upload is the process of sending data from the users computer to another

computer and download is the process of receiving data from another computer.

(ii) Duplex is a transmission system which allows data to be transmitted in bothdirections at the same time and half-duplex is a transmission system which allowsdata to be transmitted in both directions but only in one direction at a time.

(iii) Local Area Network is two or more computers linked over a small area orbuilding and a wide area network is two or more computers linked over a largearea for example across cities or countries.

(iv) With electronic mail messages can be accessed by only the addressee and with abulletin board messages can be accessed by all users.

8 Count X1 46 811 1616 3221 64

9 (a) A computer cannot execute code written in a high level language but can executecode written in machine language.

(b) After execution of an interpreter the results of the program are achieved with a

compiler. The output of the compiler still has to be executed.

(C) Read First, SecondIf First = Second then

Print the numbers are equalElse

If First < Second thenPrint First

ElsePrint Second

End if

End If

10.NoChild = 0

Read NumberLargest = Number

3


4/25

WHILE Number 999 DO

If Number = 0 thenNoChild = NoChild + 1

End If

If Number > Largest then

Largest = NumberEnd If

Read Number ENDWHILE

IfLargest = 999 thenPrint no data on families

Else

Print Number of Families with no children = , NoChildPrint Largest Number of Children = , Largest

End IF

4


5/25

CXC IT 1998

Theory Answers

1. a) Rules and regulations that govern how information is sent and received overcommunication channels.

b) (i) Simplex (ii) Half duplex(iii) Duplexc) (i) LAN (ii) Resources such as printers and scanners can be shared,d) or Files and programs can be shared,

or Better communications programs, eg. E-Mail.or Security of information if data is backed up on a network storage device.

2. a) Read / Write head b) Track c) Sector d) Buffer

3. Application Input DevicePoint of Sale Barcode reader Games Joystick

Architectural Design Pads and TabletsMultiple-choice exams Optical mark reader Publishing Scanner Cheque processing Magnetic Ink character recognitionLanguage processing MicrophonePreparing letters Keyboard

4. a) Resolution is a property of the monitors screen, that determines the clarity of thepicture.

b) Scanner, MICR, OCRc) i) Less human error during input

ii) Faster data entry

5. a) A computer program deliberately written to cause harm to a computers softwareor to cause the computer to malfunction.

b) i) Install an anti-virus program and update regularly.ii) Always scan floppies from other computers, or attachments from e-mails.

c) i) An incorrect medical entry could cost the employee a promotion.ii) An incorrect name on a certificate could render it useless to the owner

d) Deliberate tampering, hard-disk failure, virus corruption etc.

6. a) 8710 = 10101112

b) 101 00 10

c) 0101 1001

d) 1011 0101 1001

7. a) They have a fairly large capacity.They are lightweight and portable.They last very long and have protective coating against dust.

5


6/25

They are not easily erased.They give very good sound and picture.

b) i) Quick access to records and casesMatching a finger print or photo to one on file

ii) Patient record keeping

Researching illnessMonitoring critically ill patients

iii) Use of synthesizers to enhance sounds

8. a) Read A, BIf A = B then Print The numbers are equalElseIf A > B then Print AElse Print B

b) Temp = AA = BB = Temp

9. a)

X K Sum Print

5 10 45

5 15 55 10

5 20 70 15

5 25 90 20

b) 10, 15, 20, is printed.

10. Sum = 0For count = 1 o 15 do:

Read Name, ScoreSum = Sum + Score

If Score > = 80, then Grade =AElse

If Score > = 65, then Grade = BElse

If Score > = 50, then Grade = CElse

Grade = FEnd IF

Print Name, GradeEnd For

Avg = Sum / 15

Print The average score is, Avg

6


7/25

1999 Solutions

1. (I) Main Memory / Random Access Memory (RAM)Primary Memory / Main Storage / Immediate Access Storage

(ii) Control Unit(iii) Arithmetic / Logic Unit

(iv) Disk Storage / Backing Storage / Secondary Storage

2. CHARACTERISTICS DEVICES

A Modulates and demodulates signals ModemB Accepts voice input MicrophoneC Allow users to input architectural plans Graphics TabletD Reads in graphics data Scanner E Used for printing architectural plans Plotter F Used for entering text documents KeyboardG Retrieves pricing data from grocery items Barcode Reader

H Used to move the cursor Joystick/Keyboard

3. a) Any 3 of the following:

Booting/Starting, Schedules resources, Controls operation of input/output devices, Loads and initiatesexecutions of a program, Error detection, Multiprogramming/multitasking, Provides security for dataand files,Manages files, Multiprocessing

b) I) batch processingii) on-line processing / real-time processing

iii) batch processing

4. a) Any 3 of the following:

to prepare teaching materials, to store students marks,marking Multiple Choice (OMR), for teaching difficult topicssimulating experiments, Computer Aided Learning (CAL),Computer Aided Instruction(CAI)

b) Any 2 of the following

Lack of necessary resources, insufficient computers, teachers may not be able to utilize the technology,

expensive

c) Any 2 of the following

Easy access to large volumes of informationMay provide safer conditions eg. used to simulate dangerous experimentsProvide more effective use of teacher's time

7


8/25

5 a) 10110102

b) 2710

c) 1000102

d) 1000 0111

6 a) I) Used to weld components together in an auto assembly plant

ii) Any 2 of the following:

Work could be done precisely,Machines do not take industrial actionCan be used in situations which may be dangerous to humansCan be used in situations where it is necessary to have dust free and clinically clean environments

iii) One of increased costs for repair and maintenance

Work may be disrupted severely if robot malfunctions

b) I) scanner : desktop publishingii) plotter : produce engineering drawingsiii) modem : telecommuting; accessing the internetiv) MICR : Banking, for reading cheques

7. a) I) JXXFDii) I GOT IT

b) I) to prevent unauthorized access to programs, files and othercomputer resources

ii) it is the process and procedure for storing used files which need to be kept for a long timeiii) - employees may be able to fraudulently modify data on themselves or others

- employees may be able to have unauthorized access to personal data of other employees

- incomplete modification of data by one department may produce inconsistencies in the filesystem

8


9/25

8. A testing/debuggingB logic errors/ designC syntax errorsD dry run/ desk check E test data

9. a) I) -10ii) 0iii) -40

b) Print "ENTER TWO VALUES"Input A,BWhile B = 0 do

Print " ENTER NON ZERO VALUE"Input B

EndWhileQUOTIENT = A/B

Print QUOTIENT

10. I) Print " ENTER POSITIVE INTEGER"Input NPrint "NUMBER SQUARE"For NUMBER = 1 to N

SQUARE = NUMBER * NUMBERPrint NUMBER, SQUARESUM = SUM + SQUARE

EndForIf SUM


10/25

CXC THEORY 2000 SOLUTIONS

1. a) SIM: Both store instructions and dataDIFF: RAM is volatile, ROM is a non-volatile

Data can be written to RAM, but not to ROM.

b) SIM: Both can be used to store informationDIFF: ROM cannot be changed.

EPROM: can be erased and new information written.

c) SIM: Both store data in a non-volatile form. (Considered secondary storage)DIFF: Hard disk holds more data and programs and lasts longer. Floppy disk access is

slower

d) SIM: Both used to hold programs and data.DIFF: Data in primary storage is lost when electricity goes. Data in secondary storage is not lost when

electricity goes.e) SIM: Both contain instructions that tell the computer to do something.

DIFF: System software is used by the operating system or systems personnel, application software isused by everyday users e.g. Word Processing users.

2. (a) (i) The number of bits in a word ( or register) which can be processed at one time.(ii) Small high speed storage element used as temporary storage area for data being read from or

written to I/O devices.

(iii) Method of archiving data that uses a microfilm recorder to create photographs of data for storage

(iv) A measure of the amount of data that can be transmitted at one time through a communicationschannel.

(v) A network that spans a large geographical area including cities and even countries.

(b) (i) Tapping into a communications channel to retrieve information.

ii. The unauthorized copying of software.iii. Using registration keys that are only available with purchase of the

software.

iv. Penalties for anyone found with pirated software.

3. (a) high level language: allows users to write in a familiar, more English-like notation,rather than numbers or abbreviations.

b) pseudocode: a set of English-like statements used to specify the logic of an algorithm.

c) logic errors: errors which occur because of incorrect reasoning in a program (we know

d) they are present when a program produces incorrect or invalid results).

e) dry-run: the execution of a program by hand using appropriate test data.

f) compile: the process of converting from a high-level language to machine language. Italso detects errors in the use of the language.

g) syntax errors: errors which occur when the rules for forming statements in a programare violated.

10


11/25

4. (a) Using an individual password for each client file.

(b) Use fireproof cabinets to store back-up copies of files. Keep copies of data off-site.

c) Keep backup copies on disk/CD/tape/other removable storage.

d) Use data encryption.

5. (a) Teleconferencing is the use of computers, videos, audio and communicationstechnology to enable people in different locations to see, hear and talk with one another.

(b) This part was generally well done. However, some candidates made reference to theadvantages of telecommuting.

(c) Modem, camera, sound card, microphone, speakers, telephone, monitor.

6. (a)(i) Machine language can be directly executed by the computerwhereas a high level language has to be translated to machine language.

OR

A well-coded machine language program will run faster than the equivalent high-level language program.

(ii) It is easier to program using a high level language than machine language. The same program can be run(possibly with minor changes) on a different make of computer. A machine language program wouldhave to be completely re-coded to run on a different make of computer.

(b) Any THREE of the following:Sharing of peripheral devices e.g. scanners, printers.Sharing of programs and data. e.g. network version of Microsoft (R) Word.

Better communications e.g. email.Security of information. Data backed up on network storage device.Easier access to databases-private and public databases.

7. (a) 11000112

(b) 10100002=8010

(c) The 4 digit binary representation for each digit is used. A positive sign is indicated by the pattern10102, and a negative sign by 10112

(d) - 6 5

1011 0110 0101

8. (a) Algorithm to read three values a, b, c, and print the largest.

Largest = a

If b > Largest then Largest = b

If c > Largest then Largest = c

Print Largest

11


12/25

(b) (i) Trace table

A B SUM

3 5 1

8 13 14

21 34 48

55 89 137

(II) 137 is printed.

9. Write an algorithm to read a positive integer N and find the average of all even numbersbetween 1 and N inclusive. Perform any necessary validation.

Solution

Read NIfN < 0 then

print Error-must be positiveElse

sum = 0count=0

Forj =2 to N step 2 dosum= sum + jcount= count + 1

EndforIf count = 0 then

print There are no even numbers between 1 and , Nelse print Average is , sum/count

EndIfstop

NB. The Else part could also be written as shown on here.

Else

Sum=0, Count=0, Even=2

While Even < = N doSum = Sum + Even;

Even = Even + 2Count = Count + 1

EndwhileIfCount = 0 then

Print There are no even numbers between 1 and NElse Print Average is , Sum / Count

Endif

10. Write an algorithm to read the names of 10 items and their prices and print the name of the

12


13/25

item with the highest price. Assume that no items have the same price. Data is supplied inthe form: item 1, price 1, item 2, price 2, etc.

highprice = 0

For j = 1 to 10 doread item, price

Ifprice > highprice thenhighprice = priceexpensiveItem = item

EndifEndfor

Print Most expensive item is , expensiveItem.

13


14/25

JUNE 2001

CXC IT THEORY ANSWERS

1. Suggested Responses

a. Ability to write a sequence of operations using likesyntax.Ability to refer to variables in the natural state (by the

given name) rather than using binary locations in thecomputer. Ability to use the same written program ondifferent machines.

b. Logic error - error in how the algorithm goes aboutsolving the problem.Test Data Input data testing the system response to arange of inputs, including critical situations.Source Code Human Readable text version of a programin a high level language.Variable a symbolic representation of an element whosevalue can be assigned and changed.

c. To see that the specifications laid down by the analysisteam are correctly understood by the programming team,and efficiently satisfied by the programs produced.

2. Suggested responses

a. Programmable Read - System manufacturer canOnly Memory embed his own data or

instructions into the chip, aspart of the make-up of acomputer system.

b. Central Processing Unit - Carries out operations on dataspecified by the instruction code of aprogram.

Arithmetic/Logic Unit - Does the Arithmetic and Logicoperations of the computer.

Random Access Memory - Holds data and instructions about to beused by the central processing unit.


a. Data means raw information, essentially meaningless inits initial state.Information can be used and assimulated in ameaningful manner by a human, and usually input to asystem for Information is used for decision-making.i.e. Data arranged in a meaningful and organized mannerand is useful to the user.

b. (i) UPLOAD- Sending information along data communicationchannels TO another machine from the usersmachine.- With the operation being activated by the user.

If the candidate includes the fact that the other machine is

the host or the server the full two marks are given.

(ii) Wide Area Network (Definition of abbreviation)- A connected group of computers spanning a large

geographical area.- Connections usually made by some form of radio-

based linkage.c. Microfilm serial

Microfiche direct accessReel-to-reel tape serialCartridge tape serial

14


15/25


a. (i) Interact with the user and give the user a way to issuecommands to the computer.

(ii) Manage the arrangement for storing files.

(iii) Manage/Control the hardware components to allowcomplete system use. Plus a wide range of other goodanswers.

b. The menu immediately lets you pick commands withinthe context, to do operations.

c. Primary storage has a shorter access time; It is faster.

d. Disk storage carries direct access, tape is serial access.

e. Any three of the following:

- Protect the diskette from dust- Protect the diskette from moisture- Do not drop or step on a diskette- Do not store at extreme high or low temperatures-

store between 10 C to 45C.- Do not touch or unnecessarily expose the

magnetic surface.

- Do not force the diskette into the drive.


a. A plotter, because- it actually produces drawn lines with a line-

drawing action,OR

- it can, usually handle a larger paper size.

b. Problem: The ribbon is worn or ribbon is incorrectlyplaced, OR Print head gap too wide/hammers not strikingproperly.

Solution: Change the ribbon cartridge, or place the ribboncorrectly OR set the head gap.

c. The light penSignals the system when the scanning point on the screenstrikes the tip of the pen.Since the system actually can calculate where the scanning

point was located at that instant, it can tell where the penwas located at that time.

The system registers the positional changes and drawslines or does actions as required.Mouse-type button features are also included with thedevice. A light pen is light sensitive and so can also beused as a pickup device for bar-code reading.

ANY three of the above- one mark each. The notions inthe bolded text must be included in the particular answeritem.

d. Both of them recognize shape of character. BUT

The Magnetic ink character recognition reads the characterusing the ability to detect magnetic ink, whereas opticalcharacter, recognition relies on reflected light.

6. b. Answer 8510 c. Answer 1112

7. a. Personal. Information can be used in violation of privacy,for marketing purposes.

Corporate Industrial information can be surreptitiouslyused for personal or other corporate gain (IndustrialEspionage)

b. - Software restrictions can allow access to a portion of datawith restriction on access to other portions.

15


16/25

- Software restrictions can allow someone far away tomaintain access, with the appropriate privileges still inforce.

- Software restrictions can allow the system to be used forother things, which data access restrictions.

c. Telecommuting is where an employee works at home, witha long-range connection to the office computer.

Contributions:

- The Internet- High speed modems- High speed telephone lines- Satellite down-links for long range connection- The cost of maintaining a full size office.

8. a. Backing up means to create a copy of all or someinformation on a separate storage area as a safety measurein case the original is lost or damaged.

b. The read-write head reads information on the surface of themedia and puts information onto the media. (The meaningand purpose for this device can be simultaneouslyembodied)

c. The address locates the element of data. It is used inspecifying where information will be written to, or read

from.

d. Access time the average time taken to read or write anelement of data using a particular storage type. Importantdepending on the work youre doing and the speedrequired.

9. a) Answers: -1 1 1b) Answers: -2 1 2

_____________________________________________________________

10. PRINT ENTER THE INTEREST RATE AS A DECIMALFRACTION INPUT R

PRINT GIVE THE NUMBER OF YEARSINPUT N

PRINT GIVE THE STARTING BALANCEINPUT BALANCE

FORYEAR = 1 TO M DoBALANCE = BALANCE * (1 + R)

NEXT YEAR

PRINT THE BALANCE WILL BE, BALANCE_____________________________________________________________

NB Prompts 1 mark, Consistent variables 1 mark, Print 1 mark, Loop 1mark, Formula 1 mark.

16


17/25

CXC IT JUN 2002

Answers

1. (a) Control Unit and the ALU

(b) Control Unit controls the internal operations of the CPU, interprets program instruction

and controls the flow of data through the computer.The ALU is responsible for all calculations and comparisons in the computer.

(c) E PROM can be erased by ultra violet rays and reprogrammed where as PROM can onlybe programmed once and not erased.

(d) Transmission where data can be sent or received but not simultaneously e.g. CB radio.

2. (a) The file may have been corrupted or the disk damaged in location of thefile.

(b) File Allocation Table (FAT)Table of information the operating system uses to locate files on a disk. It contains files,

file types and locations.

(c) In a fixed system on a hard disk. The heads are positioned 1 over each track therefore theheads do not have to move in and out to get tothe required track. Access is immediateand therefore faster.

(d) A track is a concentric ring on the surface of a disk on which data is stored. A cylinder ismade up of all tracks of the same radius on different platters all lying one above the other.

(e) (i) k =1/2 x 1024 = 512 k or approx 100k (ii) No. of bytes in whole cylinder = 6 x 10 x 512

= 30720 KB3. (a) 1 byte = 8 bits, 32 bytes = 4 bytesA 32 bit machine needs to transfer data 4 bytes at a time while the ole needed on

(b) Decrete data is data that can be counted only as wholes. Eg. Books. Integers are wholenumbers without decimal parts therefore good for discrete data. Continuous data has tobe measured. Eg. Height Real numbers and floating point systems have fractional partstherefore suitable for continuous data.

4. (a) Magnetic tape is serial because to search for a data item one has to start atthe beginning of the tape and search until the data is found.

(b) Floppy disk is a direct access medium because the drive locates the item by goingdirectly to its address.

(c) Microfilm is a real of film about 100 200 ft long on which is stored microscopic imagesof documents.

5. (a) 2 applications of OMR (ie. 2 uses)(i) to mark multiple choice exams.(ii) to collect data from survey forms.

(b) OCR = Optical character Readeror Optical Character Recognition.

17


18/25

(c) 1024 x 768 resolution has more pixels per square inch than 640 x 480. Therefore it willgive a clearer picture.

(d) Advantage: Touch Screen is easier to use than a mouse.Disadvantage : i) Touch Screen more expensive than ordinary monitor, (special softwarerequired), (ii) Selections limited as touch points need to be big enough for a finger. Alot more options available with the mouse.

(e) Custom software is software created specifically for a user.Customized software is general purpose software bought off the shelf but altered to suitthe needs of the user. The user pays a fee.

6. (a) (i) 10 = 1010210 as 8 bits = 0000 10102

(ii) 10 = 000010102-10 = 11110101 (ones complement rep)

(iii) 10 = 000010102-10 = 11110101 (twos complement rep)

+111110110

(iv) 10 = 00001010210 = 1000 1010 (Sign & Magnitude rep)

(b) (i), (ii) and (iv). If there are any 1s then the number of ones areeven.

7. (a) (i) Game playing joystick, wheel, speakers.

(ii) Teleconferencing microphones, speakers(iii) presenting a report printer, scanner.

(b) Line printer prints characters, 1 line at a time and is faster than a character printer whichprints 1 character at a time.

8. (a) Some one joins a newsgroup to (1) read and discuss news items on a particularsubject. (2) Write and post news items on a particular subject.

(b) Internet Relay Chat users send and receive typed messages instantaneously across the

internet while maintaining live contact with many other users at once.

Electronic mail messages sent from one computer user to another to a location the enduser can access via his computer at a time convenient to him. The 2 users are not in livecontact. Messages may not be read instantly.

(c) (i) HTML Hypertext Markup Language a language used to format,style or create web pages.

18


19/25

(ii) File Transfer Protocol (FTP) a standard used to upload and download files withother computers on the Internet.

(iii) CADD Computer Aided Design and Drafting. - software used to producearchitectural and engineering drawings on a computer.

9. (a) (i) Cost of transportation from address to work or the distance between (i.e.mileage)

(ii) The names and addresses could be given without their consent to someone whowants to do business with them.

(b) - Keep back up copies on disks in a fire proof cabinet.

- Keep back up copies at another location.

10. (a) Electronic eavesdropping the unauthorized use of electronic devices

capable of intercepting, recording or printing electronic communications or moving data.

(b) The password is to give the user the ability to descramble or restore the file to its originalform.

(c) To create and maintain the network.To provide security i.e. to control or prevent access to different files and folders or to thenetwork itself.

11. Read A, B Read X,YAverage = A + B OR Sum = X + Y

2 Average = SumPrint Average 2

Print Sum

12. For Count = 1 to 100 Do

Read Name$, Price IfPrice < 50 then

Print Name$ End IF

End for

13. Read Name$, Age, Sex$

WHILE Name$ End DO

IF Age 2 thenIFSex$ = M then

IfAge > 15 thenFee= $50

Else

Fee= $40End IF

19


20/25

Print Name$, FeeEND IF

IFSex$ = F then

IFAge > 15 thenFee=$40

Else

Fee=$30

END IFPrint Name$, Fee

END IF

END IF ENDWHILE

14.

Z = Z + XX = Z XY = Z + YZ = Y Z

Y = Y X ZPrint

X Y Z

1 2 3

4

3

62

1

3 1 2

20


21/25

CXC IT

TECHNICAL

SPECIMEN PAPER THEORY 2002

(ANSWERS)

1. a) 512 bytes = Kilobyte. K x 18 sectors * 80 rings (tracks) * 2 sides = 1440 Kb

b) A byte is the smallest unit of data storage that can be directly accessed in memory.A word is the amount of data that will flow in the systems data bus in one instance. It is

the amount of data the system will access at one time

2. a) Application software is used for the user to achieve what he plans to achieve.

System software is for the purpose of getting the system ready, preparing it for work andimproving or optimizing its performance. Such as operating system functions)

b) 3 functions of the operating system

i) providing a user interface- user startup screen or desktop

ii) organizing file storageiii) scheduling of tasks. (queueing and handling jobs.)iv) providing securityv) providing & protecting reserved memory storage for running applications.

c) It is much easier to access a file, program or function by clicking on an icon or graphic. You donot have to learn and memorize commands to type at the keyboard as is required for commandline interface.

d) A plotter may be preferable to a page printer if it is necessary to draw continuous lines acrossmultiple pages. The work of a plotter is to draw lines. When drawing plotted lines a plotter ispreferred.

3. a) Folders can be used to group files of a similar topic, purpose or time.Folders reduce the amount of time spent searching for a file.

b) He can get a listing of all files created, (also modified or accessed) on a particular day. InWindows he can click Start/ Find/ Files or Folders/ Select the folder to search (eg C or FloppyA) / Date tab/ find all files/ Created/ between or during dates you type in.

4. a. Underodd parity, the number of 1 bits in a byte must come to an odd number. If theydont then the 9th bit is set to 1 so the total number becomes odd.If in the eight bit byte the number of 1 s is already odd the 9th bit is kept at 0. If ontransmission of the byte the number of 1s among the 9 bits is not odd, then an errormust have occurred.

Undereven parity the total number of 1s is kept to an even number amongst the 9bits.

b. (i) D to C : subtract 1. Answer 1000 011

(ii) D to G : Add 3. ie add 112 Answer 1000 111

c. Answer 73. d) Answer 11 001

e. Answer 101 11001

21


22/25

5. a)

b. Bar code - a sequence of vertical printed bars that represent a number used toidentify an item or person.

c. 2 ways a bar code is used in an accounting system

for identifying & pricing of an item at the Point of Sale

to keep track of items sold and their numbers

d. Ready made software is cheaper to obtain and is more likely to be familiar to theemployees. Also a large no. of people use readymade software therefore newemployees may already be familiar with it.

6. a. Electronic mail means messages prepared by 1 computer user & sent toanother via

computer to be stored in a location accessible to the other via a computer.

c. Broadcast transmission is an arrangement with multiple systems where a transmission issent to all machines simultaneously.

.d. A newsgroup is a list of articles, accessible via computer, written and read by varioususers who are interested in a particular area of discussion.

7. a) Internet Relay Chat see Internet Concepts handout.

b)Telecommuting is where an employee can work outside the regular office and cancommunicate with the company via email, direct dial up into the computer network,and other electronic method.

c) Teleconferencing is where a group of people can communicate live with the live

Differences

OCR MICR The characters need only be clearlyformed then it can be identified using alight- sensitive reader

Sensing of magnetic ink is required toidentify the characters

Or able to use the entire alphabet and

can now accept well shaped handwritten characters

Restricted to numbers primarily

Similarity

both direct input into the computer. Both involve sensing of characters

22


23/25

transmission of voice and video

d. Telemarketing is the use of telephone lines and computers to market products,manage accounts & communicate with customers.

.e. Web Browser - see Internet Concepts handout.

8. a) Three purposes for which a company can use its web site See Internet Conceptshandout.

.b) One other way in which the internet facilitates buying and selling items :The buyers & sellers can communicate on the internet but use mailed cheques instead offinalizing payments over the internet.

c) http is the protocol that specifies the kind of transfer method to be used.

www means World Wide Web

icl-yes is the name of the internet sever

com is the domain (commercial)

students.htm is the specification of the hypertext file to be viewed.

9. a) Encryption means converting a document to an unreadable form to be deciphered only bythe use of a password.

.b) Someone may leak out the password or code to a friend who is unauthorized. With

physical access restrictions only authorized users can use the computer.

.c) Use up-to-date antivirus software, Operate a good back up system

Write protect your diskettes whenever copying files to a strange computer. Use software from bona-fide sources only.

10. The Systems Analyst :

Investigates the current system with a view to making computer based improvements.

Plans the design of the new Information Technology system

Overseas the introduction of the new information system.

The Programmer must

design the program(s) based on the system specification. (ie based on the computers andsoftware available and the requirements laid down by the analyst)

Produce documentation for the program. (so that users can understand & to help laterprogrammers make updates or alterations necessary).

Prepare the program and test it.

Maintain the program during its operation. (Ie. fix an errors that may come up)

11. Read X, Y

IF X = Y then

Print They are equal

23


24/25

ELSE

If X > Y then

Print X, is the bigger of the two

Else

Print Y, is the bigger of the two

End If

END IF

12.. Print How many numbers are there?Input NSum = 0

ForI = 1 to N do

Print Number , IPrint Give the valueInput X

Sum = Sum + X

End For

Print THE SUM IS , Sum

13. ForI = 1 to 15

Input Personname$, Income

IfIncome < 200 000 thenTax = 0

Else

IfIncome


25/25

4 8 4

4, 4, 4 will be printed for X,Y,Z

25

Documents

CSEC Theory Exam 97 - 2002 Answers