1. (i) Expand the following acronyms giving explanations in each case
(a) BCD
(b) ASCII
(c) EBCDIC
(ii) What is a robot?
(iii) Explain two .uses of computers in the following orgnization;
(a) Military
(b) Education
(c) Hospital
-(d) Multinational corporation
(e) Manufacturing industry
(iv)
(a) Convert the decimal number 120 to an, octal number.
(b) Convert the binary number 101101001 to an octal number. Design and complete the truth tables of the following logic operators OR and NAND.
2. (i) Give three reasons why data misuse is more easily carried out in a computer
system than in a manual system.
(ii) (a) What is a computer virus?
(b) State two actions of a computer that may suggest the presence of a virus in it.
(c) Write down four ways in which you can prevent a computer virus infecting your computer.
(iii) What aspect of computer security does each of the following describe?
(a) prevent access to unauthorized computer
(d) used for security and change regularly
(e) Restrict access to certain users.
(f) Data may be stolen but cannot be read.
(v)
State and briefly describe one other security method to protect the data of
an organisation. (3 marks)
(i)
(a) Name and briefly describe THREE internal threats to ICT systems (6 marks)
(b)Name and briefly describe two external threats of an ICT system( 4 marks)
(c) Describe three measures you would fake to protect your ICT system
from illegal access. ( 3 marks )
(ii)
Explain what is meant by:
Filename
File compression
File Allocation Table (FAT) A
(b) Give two reasons why it is necessary to defragment a hard disk (3 marks)
The file compression ratio of a disk compression utility is set, at 15:1. (2 marks)
lithe contents of the hard disk is 28 GB before compression,
what would it be compressing the data with this compression utility?
Give your answers in GB and MB.
(2 marks)
(i)
What is Batch-processing? (2marks):
How is a batch processing system different from real-time processing–system? (1 mark)
(ii)
(a) Which two of the following systems are batch processing systems?
– Reservation systems
-Payroll
– Billings
Explain choice of answers.
(b) Give three ways in which office staff will be affected by the introduction of a
computer system..
(a) Explain’ the following terms: Modeling and simulation. (5 marks)
(b)Describe one situation which can be modeled and simulated. (5 marks)
(i) Computer users with different disabilities require special hardware and software. Complete the
table below stating in each case, special hardware and/or software for people with the given disabilities.
| Disabilities | Hardware /software |
| Limited mobility | |
| Armless | |
| Slow typist | |
| Blindness | |
(i)
(a) What is data capture? (2marks)
(b) Give three examples of automatic data capture methods, explaining how each method is carried out.
(a) what do you understand by intranet and extranet (3 marks)
(b) use the features used in the networks above
(c) How useful are these to an organistion ? ( 3 marks)
.
(i) Define each of the following terms:
(a) Telecommuting.
(b). Videoconferencing
(c)Expert system
(d)Loader
(i)What is system software? (2 marks)
Name and describe Four categories of system software and give an example for any TWO –(6marks)
(ii)
Fully expand each of the following acronyms giving a brief explanation of-its use in each case.
(a) GIS (b) HIS (c) EIS (d) LIS (4 marks)
What is Management Information System (MIS)? (1 mark)
Raports are very essential for managers who use them to make good decisions, Name and briefly
explain three types of MIS reports. (3 marks)
A payrll system has just been created for an agricultural firm of 50 workers
i)Describe THREE main steps that may be taken to implement the system. (3 marks)
ii)Describe two verification methods that the firm could use when entering data into the system.
(4 marks)
iii)Describe THREE .system input controls using specific examples. (6 marks)
(iv) Describe two measures taken by the organization to ensure that data is not accidentally lost (2 marks)
(v) Describe how, upon installation, the system can be tested (5 marks)
8. A school has a manual library system which is run using the following rules:
– Books are grouped according to SubOcts in shelves.
– Books have codes-on them.
– Students have access to the library.
– Each student has a school ID card.
– The record of books borrowed by students is stored on cards which are kept in the library.
(i) Give six data -structures (gelds and data types) of the details found in a borrower’s card.
Present your answer in a tabular form. (6 marks)
A system analyst is hired to design a computer system.
(ii) State and explain three ways of collecting information about the current system (6 Mark)
(iii) State four items of information that should be part of the design of the computer system.
(4 marks)
(iv) Design a suitable output format for displaying the details o; a borrower. You may annotate your
design to make it clear.
(i) Write down the formula you will use to calculate the determinant of the matrix -whose entries are in
the table. (2 marks)
ii) Rewrite the equivalence the formula above using a spreadsheet function, such. as MDETERM in
Excel, which computes the determinant for any m x n array, or otherwise. (2 marks)
Write a program in a stated programming language that reveals inputs of four integers, a, b,c and d
and displays the determinant of the matrix obtained form them as given above.
(8 marks)
(iv) (a) What is pseudo code? Give two rules for writing pseudo codes. (1 marks)
(b) What is the difference between pseudo code and source cede? (2 marks)
(c) Give the importance of pseudo code. • (2 mark)
