• Bus topology is characterised by common transmission media shared by all the connected nodes
• Star topology is characterised by a central switching node connected directly to each of the multiple nodes in the network

Advantages of Star topology over Bus topology

• Faster communication as compared to bus topology
• Independent line of connection allows freedom of removing or adding nodes

Disadvantages of Star topology over Bus topology

• Expensive as compared to the bus topology
• Long cable length

Any four of:
Sequential:
• Individual instructions are executed one after another
• Flow control is accomplished by jump/branch/goto instructions
• Results are usually achieved less quickly than parallel processing (do
not award twice)
Parallel:
• Individual instructions can be routed to different processors for
simultaneous execution
• Results are usually achieved quicker than sequential instruction (do not
award twice)
• Requires multi-core processors or multiple microprocessors
• Tasks may be split into different parts with each part executed on a
different processor
• Results need to be merged back together after completion

1. MAN
2. WAN
3. PAN
4. LAN

1. Identify any computer output device suitable for each of the following tasks:

1. Generating receipts where carbon copies are required  (1mk)

• Impact printers e.g dot matrix

     b) an architectural drawing where precision is required         (1mk)

• Plotter

(c ) producing document output for a visually impaired person (1mk)

• Braille/speakers

1. Pesa Tele has offices in Nairobi and Kampala connected in a network . the management is convinced that someone is illegally gaining access to the data in their computers. State three ways in which the company can overcome this problem (3mks)

• Encryption
• Firewall
• Audit trail/tracking
• Use of passwords
• Limit the number of log-in attempts

1. Explain two ways in which the use of internet could make reporting of corruption easier (4mks)

• Interactive: the internet based technology enables real-time dialogue hence instantaneous reporting of cases
• Outreach: the technology allows the coverage of wide areas
• Social mobilization : it easy to create a network of people with similar concerns
• Anonymity : it is easier to report corruption without being  known
• Security: the message sent reaches destination without being intruded

1. State ways in which software errors can be prevent during program development

• Use of antivirus software
• Performing system update frequently
• Testing the software before implementation
• Proper training

• star - if one computer goes down the others can still be used
• ring - if one computer goes down the others can not be used

• It covers many aspects that will be used to decide whether to go ahead with the project or not.
• The main components are technical, operational, economic, legal and scheduling.

• an attribute/combination of attributes chosen to ensure that the records in a table are unique

Domain integrity - ensures that all data in  a field contain valid values

• Radiowaves are omnidirectional while microwaves propagate in one direction at a time(unidirectional)
• Radiowaves can be propagated over long distances through sky mode while microwaves require a relay satellite to amplify and retransmit the microwaves signals to the receiver earth station

• Simple Mail Transfer Protocol (SMTP)
• Post Office Protocol (POP)
• Internet Message Access Protocol(IMAP)

• StudentID: String
• FirstName: Required 1
• Year: 2 1
• Email: Email address containing @ sign 1
• AccountBalance: Real

 the trial version of software for a limited time/number of uses with limited features  free of charge

If a full version is required need to pay a fee/sign up

When the trial is over user is asked to pay/sign up

Protected by copyright

Type of software licence
 

• The process of rewriting parts of a file to contiguous sectors on a disk

Twisted pair cables

Coaxial cables

Fibre optic cables

Manages memory (RAM) 

• Allocates memory to programs currently executing •

Ensures programs/data do not corrupt each other: Ensures all programs and data including itself is stored in correct memory locations

Manages processes: Ensures different processes can utilise the CPU and do not interfere with each other or crash •

Allows a user to run programs : On a multi-tasking O/S ensure that all tasks appear to run simultaneously

• Allocates time slices 
• Scheduling of programs
• Handles interrupt
• Allows a user to configure hardware

• Computer systems use binary/ones and zeros/voltage on or off;
• Sound is analogue/continuous;
• Computers use digital data/discrete values

• A physical file contains the original data whereas a logical file does not contain any data
• A physical file contains one record format while a logical file can contain up to 32 record formats
• A physical file can exist without a logical file while a logical file cannot exist without a physical file

• Access Controls: Authentication of users in order to access files
• Performing regular patches of updates
• creating secure accounts with required privileges
• scrutinizes all incoming and outgoing packets of data through a firewall
• encryption of data, during transmission
• Log files to detect any breach

• confidentiality - The principle of protection from unauthorized access or disclosure
• Integrity - the principle of ensuring that unauthorized or undetected changes to data or system configurations do not occur.
• Availability - the principle of ensuring that data and services remain accessible to authorized users at all times

– fact finding
– feasibility study
– analysis
– design
– testing
– documentation
– implementation/changeover/installation
– evaluation
– maintenance