2020 Paper Flashcards
Describe what is meant by the term client server
- Client computer connect to a server
- The server then provides access to a service
Give 2 advantages of a client-server compares to a peer-to-peer server
- A client server is easier to keep data secure
- A client server only has one point of failure
- A client server is easier to backup
- A client server is easier to manage
Explain the purpose of a network switch
- A network switch connect computers together on a LAN and receives and sends packets
Describe what is meant by the term ‘foreign key’
- A foreign key creates a join to a primary key in a second table
Describe two ways that hashing could be used in this database
- Hashing is used for security and hashes passwords in a database to ensure passwords cannot be read if stolen
- Hashing is used for direct access on records by using hash of index as address
Explain what is meant by the term ‘referential integrity’
- Each foreign key must link to an existing primary key
- This is broken if the primary key is updated/deleted and the foreign key is no longer valid
State the purpose of a D-type-flip-flop circuit
- A D-type-flip-flop circuit stores the value of one bit when a signal is given
Describe the inputs and outputs used by a D-type-flip-flop circuit, explaining how the inputs are used to control the outputs
- Data is the input and clock is the input
- Q is the output and not Q is the reverse of Q
Write a program using LMC that will allow a user to input two numbers and then output the larger of the two numbers. The program should loop continuously
Start INP
STA x
INP
STA y
SUB x
BRP first
LDA x
OUT
BRA start
first LDA y
OUT
Describe two ways that an operating system could manage physical memory
- Paging could be used which splits up memory into 4K fixed chunks
- Segmentation could be used which splits up memory into logical sizes that vary
Explain benefits of memory management to the user
- Memory management increases security for the user as the program cannot access memory kept for other programs
- Memory management enables multitasking for the user as multiple programs can run at once
Describe how virtual memory allows a user to run programs when physical memory is full
- Pages that are not required are moved from memory to second storage to create room in memory
- Then pages are moved back to memory when required
Describe what is meant by the term ‘device driver’ and give on example
- A device driver is a software that allows the OS to communicate with hardware
- Example a webcam driver, printer driver
Give examples of utility software explaining the purpose of it
- One utility software is compression which reduces the size of files and increases memory
- Another utility software is encryption which scrambles up the meant of data with a key to increase security
- A third utility is backup which makes regular copies of files incase it’s lost
State what is meant by the term ‘open source software’
- An open source software is when the source code is available to the public to edit, modify and recompile
