Topic 4 - Computer Systems Flashcards
What is a computer?
A programmable device that takes data and outputs information
What are general purpose computers?
Devices with a variety of uses, the user chooses the task
What are examples of general purpose computers?
PC
i-pad
Laptop
What are embedded systems?
Device that only do a limited number of things
What are examples of embedded systems?
Thermostat
Coffee machine
Vacuum cleaner
What is the CPU?
Central Processing Unit
It controls everything
What does RAM stand for?
Random Access Memory
What does ROM stand for?
Read Only Memory
What does RAM store?
Instructions and data currently in use
What does ROM store?
Permanent instructions - ie. BIOS
What has more storage RAM or ROM?
RAM
Is RAM or ROM volitile?
RAM
What are RAM and ROM examples of?
Main Memory
What is a hard drive?
A main storage device
What does the hard drive store?
Files
Operating system
What is BIOS?
The basic code for controlling hardware
What do buses do?
Carry data around the CPU
What do clocks do?
Regulates FDE cycles per second
What does the Control Unit do?
Controls other components
What does the Arithmetic Logic Unit do?
Mathematical operations
What are registers?
Fast access memory locations within the CPU
Explain the execute cycle
The control unit tells the other components what to do
What does the cache store?
Frequently used instructions
Explain the cache’s levels
L1- Fastest & least storage
L2 - In between
L3 -Slowest & most storage
How does solid-state storage work?
Uses electricity and stores data in 0’s and 1’s
How does optical storage work?
It uses a laser to read and write
Pits and lands represent 0’s and 1’s
How does magnetic storage work?
Uses magnets to read data
What are the advantages of solid-state storage?
High speed
Durable - no moving parts
Uses less electricity - no moving parts
Potable
What are the disadvantages of solid-state storage?
Expensive
What are the advantages of optical storage?
Cheap
Portable
What are the disadvantages of optical storage?
Not durable
Small capacity
What are the advantages of magnetic storage?
Large capacity
Cheap
What are the disadvantages of magnetic storage?
Requires power
Not durable - moving parts
What are examples of solid-state storage?
USB
SSD
What are examples of optical storage?
CD
DVD
Blu-ray
What are examples of magnetic storage?
Floppy disk
Hard disk drive
What is the symbol for the AND logic gate
P = A.B
What is the symbol for the OR logic gate
P = A+B
What is cloud storage?
A way to store and access files through the internet
How is data stored in cloud storage?
In hard drives in server farms
What are the advantages of cloud storage?
Capacity can expand
Files can be accessed anywhere
You can easily share files
Centralised back-ups
What are the disadvantages of cloud storage?
Relies on stable internet connection
Slower than secondary storage
Security risk
Data in hands of providers
How can you improve PC performance?
Increase clock speed - More FDE cycles per second
Bigger cache - Slower to fetch from RAM
More cores - More programs can be run at once
What are examples of high-level languages?
Python
What are examples of low-level languages?
Assembly languages
Machine code
What is high-level languages?
A language used to write computer programs that ahs to be translated before it is executed
What is machine code?
Program code in binary that the computer understands
What is assembly language?
A code that uses mnemonics/ abbreviation
What are advantages of high-level languages?
Easy to learn
Easy to understand
What are advantages of low-level languages?
Give complete control over the components
Uses less memory
Executes faster
What does an assembler do?
Translates assembly language into machine code
When is a compiler used?
On frequently run software
When is a interpreter used?
During program development
What does a compiler do?
Translates the whole program at once
What does a interpreter do?
Translates one line at a time
What are the advantages of a compiler?
Faster
Cannot see source code
What are the disadvantages of a Interpreter?
Slower
Can see the source code
What are examples of Application software?
Web browsers
Photo-editing tools
Video-editing tools
Spreadsheets
What are examples of System software?
Operating system
Utility software
What does the operating system do?
Controls hardware
Provides user interface
Manages memory
Manages applications
Manages security
Manages processes
What does Utility software do?
Encryption software
Defragmentation software
Data compression software
Back-up software
