Computer Systems Flashcards
What is hardware?
What is software?
Hardware is the physical components that make up a computer system.
Software are the programs that run on a computer including the operating system.
What is system software?
System software programs that are needed for effective communication with the hardware and for launching application software
What is application software?
Application software programs launched from the operating system to perform a specific task.
What is operating system?
Operating system is a piece of system software that acts as an interface between the user and the hardware managing all hardware and all other software
What does the operating system control?
The operating system controls processors, memory, I/O devices, Applications, Security
What is utility software?
What does it do?
Utility software are programs that keep the computer functioning efficiently by freeing up storage space, removing viruses, or ensuring files are backed up.
What is the CPU?
The central processing unit executes program instructions, performs calculations, and coordinates the behaviour of hardware
What are the components of CPU and their functions?
ALU performs various operations
CU manages the execution of instructions by coordinating the hardware
Buses are collections of wires that transmit data between
the computer and computers
Registers a short-term storage for specific pieces of data
Clock regulates the the number of activities that happen within the CPU each second
What is main memory?
The main working area of data currently being used and programs currently running. Consists of ROM and RAM
What is RAM?
Random Access Memory is where data and instructions are loaded on to the computer’s hard disk.
It is generally faster, volatile and can run applications concurrently
What is ROM?
Read Only Memory. Content cannot be edited or deleted and so is non-volatile and so do not need to be updated. ROM stores bootstrapping instructions which tell the computer the first steps to initialise the computer
What is cache memory?
Cache memory stores copies of data or instructions from RAM that are accessed very regularly meaning they can be accessed very quickly.
What determines the CPU’s performance?
Number of cores
Clock Speed
Size of Cache
Type of Cache
What are cores?
Single units comprising of the ALU and CU which can execute instructions. More cores means more instructions can be performed per second.
Describe the Fetch-Execute Cycle?
One of the registers contains the locations where the next instruction is found called the ‘PC’
PC copied to MAR
When an instruction is being transmitted, it is stored in a register called the ‘MDR’ then transferred to ‘CIR’
The instruction is read by the CU which prepares the registers for data to be stored
Then instruction is carried out by retrieving data, performing an operation in the ALU and storing in the memory