– multiple choice/yes-no answers
– easy to understand interface e.g. use of icons/drop down menus etc.
– output shown as % probabilities of fault

(a) \(F C_{16}\)

(b) \(8 A_{16}\)

(c) \(93_{10}\)

(a) byte

• fixed number of bits, 8 bits
• represents a character

(b) compiler  program

• converts/changes/translates high-level language into machine code/machine language/low-level language/object code
• changes each high-level language instruction into machine code instructions
• produces an independent program capable of being executed by itself
• all (syntax errors) listed
• converts the whole program before execution/in one go
• converts source code to object code

(c) handshaking

• exchanging of signals to establish communication between two devices/computers e.g. printer and computer, modem and computer

(d) technical documentation

• documentation to ensure that the system can be maintained/updated/altered/developed/upgraded
• trouble shooting/correcting errors/correcting faults
• explanation of what the program does/how the system works
• contains file structures
• algorithms/flow charts/pseudo code
• program listings
• hierarchical chart

(e) simulation

• studying the behavior of a system by using a model/represents real-life/mathematical representation
  e.g. flight simulator (or others), hazardous applications results can be predicted

• Implementation

State the characteristics of each of the following network topologies (KCSE COMPUTER STUDIES 2021 )

i) Mesh Topology  (2mks)

• a host/node is connected to one or multiple hosts
• a   host/node in point to point connection with every other host or a few hosts
• hosts/nodes in mesh topology also work as relays for other hosts which do not have point-to-point links

(ii) Ring Topology (2mks)

• each host/node connects exactly to two other hosts
• data travels around the ring in one direction through all intermediate hosts
• failure of any host results in the failure of the whole ring

• consists of values between 0–255 / 0–FFF
• values are separated by full stops/colons
• it is a unique address
• can be static or dynamic
• can be public or private
• can be IPv4 / have four groups of digits
• can be IPv6 / have eight groups of digits
• in IPv6 :: can replace groups of zeros.

• VM is used when RAM is full  i.e part of the secondary storage used as (temporary) RAM/VM
• Data from RAM is moved to the secondary storage/VM (to make space in RAM)
• RAM can then be filled with new data
• When data in VM is needed it is moved back to RAM

• The different factors that can influence the performance of a network include: bandwidth, network design, data collisions, and excess broadcast traffic.
• The bandwidth can influence through the method of transmission and medium used

1. Availability in the market
2. Initial and maintenance cost
3. User friendliness
4. Compatibility
5. User needs

• reduced labour costs/do not need paying
• reduced cost of goods
• improve speed of production/productivity
• high degree of accuracy/precision/less errors
• can operate where humans can not go
• do not take breaks/holidays/get tired
• work 24 hrs a day
• reduce accidents at traffic lights
• improve traffic flow
• can work in dangerous conditions

• Standards specify a set of rules for hardware and/or software used in network communications. Because all manufacturers must adhere to the standards when manufacturing network hardware or software, it means that all devices should be able to communicate, regardless of manufacturer.

• Better/improved traffic flow control
• reduces accidents
• keeps delays to a minimum
• reduces pollution
• cars use less fuel

Without a primary key, a table in a database may have duplicate rows, making data not uniquely identifiable. This can lead to issues with data integrity and challenges in maintaining relationships between tables. Retrieving and updating specific records becomes problematic, and setting referential integrity constraints is impossible, potentially leading to loss of data.

logging on

•  dial-up/communications software/ISPsoftware

finding websites

•  browser/search engine

• Sequential
• Random
• Serial
• Indexed-sequential

• A software which can display a webpage on a user's computer screen

• All the characters and symbols that can be represented by a computer system.
• Each character and symbol is assigned a unique value.

(b) One disadvantage of using the Unicode character set, instead of the ASCII character set, is

that the text stored takes up more storage space

• Each character is encoded using more bits

1. Low level languages do not resemble natural languages they are made up entirely of bit patterns
2. Low level languages produce code that is executed faster as it is already in a format the CPU can execute / does not need to be translated.
3. High level languages are easier to understand / learn as commands are more like English / identifiers can be meaningful .
4. High level languages are easier to use leading to fewer errors.

• Unfamiliar graphics or quizzical messages appear on the screen
• Programs taking longer than usual to load
• Less memory allowance than usual
• Unusual error messages occurring more frequently

System analyst

Web designers

Network administrators

Database administrators

Programmers

Computer technicians