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Higher Computing Science > Computer Structure > Flashcards

Flashcards in Computer Structure Deck (30):

What is the control unit?

- Controls the fetching and executing of instructions and controls the flow of data through the processor
- Co ordinates the activities of the other units with the CPU


What are the registers?

- They hold data being processed to and from memory
- Instructions being executed
- addresses to be executed


What does the address bus do?

- Holds the address of memory location being accessed
- The more lines on bus the more locations addressed
- It is one way only


What does the data bus do?

- Carries the data bring processed from processor, memory and other devises
- Each line carries 1 but therefore the more lines the more data transferred at the same time
- Two way data transfer between processor and memory


What does the control bus do?

Made up of separate lines each with own functions e.g - clock, interrupt, reset, read, write


Describe the fetch execute cycle.

1. Instruction fetched from memory
2. Decoded and executed
3. Next instruction fetched from memory
4. Decoded and executed


Describe read from memory.

1. Processor sets up address bus with address of location to be accessed
2. Processor activated read line on control bus
3. Memory releases data from specified location onto data bus


Describe write to memory.

1. Processor sets up address bus with address of location to be accessed
2. Processor sets up data bus with data to be written
3. Processor activated write line on control bus
4. Data on data bus is transferred to appropriate memory location


What is a cache?

An area of memory between processor and main memory, usually small for access and faster access than main memory
Used to improve system performance


What is static RAM?

The access time is faster when retrieving data from cache over RAM


What is an emulator?

- Creates a virtual version of absent hardware
- Uses the software version of absent hardware to let software not designed for the host system run as if it were accessing the absent hardware


What is a virtual machine?

Creates a virtual version of software
Used the hardware on the current system to run software within a virtual operating system


What are cloud advantages?

- Automatic uploading of files when connected to the cloud
- Automatic backup of data without having to create a backup of data without having to create a backup schedule
- Collaboration and file sharing


What are cloud disadvantages?

- Can only access files if internet connection present
- User can lose legal rights to their original material if they store it online
- User has no control over security measures in place to protect their files


What are features of data storage?

Allows users to upload files and access again from any connected internet device
- Vairsble amount


What are trojans?

•Malicious program that hides inside another seemingly harmless program.
•When activated they spread through the computer stealing data or damaging the computer.
•Control the infected computer
•Can Be used to open backdoor poets to allow hackers access to your computer


What is adware?

• software that plays or downloads unwanted advertising content to your computer
• commonly seen as banners or pop ups
• collects information about browsing history
• some adware is legitimate and will inform you what data is gathering about you


How do you avoid hardware?

- run adware removal program
- use pop up blockers


What are tracking cookies?

- A regulars cookie is essentially a small test file which contains data that the page will load for you upon subsequent visits
- Tracking cookies are specialised versions of cookies that record your entries and report them back to where the cookies designer wants your data to go


How do you stop cookies?

- Reject tracking/ 3rd parry cookies
- Delete cookies
- Change privacy settings


What is a router?

Needed to connect two different networks, most commonly linking a home or business network to the internet


What are hubs?

A hun will take data/ signals that it receives from the server and/ or the router and will transmit the same data/ signals to every device connected to the hub.


What is a switch?

A switch serves the same purpose as a hub and is designed to make sure that data can be transferred between devices on a network


Why is a switch more effective than a hub?

Switch used MAC addresses to make sure that data packets are only sent to the device that needs the data.


What are the two types of transition media?

Wired and wireless connection.


What is a wired connection?

Computers within a network are usually connected through ethernet cables. These cables connect to the WAN or ethernet port on a device


What is a wireless connection?

Computers can make a wireless connection have a wireless network interface card or wireless routers that provides a connection with the physical network. Device needs to be within range of the access point or router to be able to send and device data.


What are advantages of wireless connection?

- Cheaper on going and initial set up cost
- Not ties down to a specific location
- Can connect multiple devices without the need for extra hardware
- Less disruption to the building due to no wires being installed


What are disadvantages of wireless connection?

- Interface can occur
- Connection is not stable
- Lose quality through walls or obstructions
- More open to hacking


What is an optical fibre?

Uses light to transmit data through very thin strands of cable at high transfer rates