Section 1: Components of a Computer System Flashcards
(45 cards)
What is a computer?
A computer is a machine that processes data.
Its purpose it to take data, process it, then output it.
What is an embedded system?
Embedded systems are computers built into other devices. They are often used as control systems - they monitor and control machinery in order to achieve a desired result.
As they’re dedicated to a single task, embedded systems are usually easier to design, cheaper to produce, and more efficient at doing their task than a general purpose computer.
What are the 9 main parts of a computer?
1) Power supply - supplies power to the machine.
2) Case cooling fan - extracts hot air from the computer case.
3) CPU heat sink and cooling fan - keeps the CPU at a steady temperature
4) CPU - Does all the processing
5) Optical drive - for read/writing of optical disks
6) RAM sticks - used for computers memory
7) Hard Disk Drive - Internal secondary storage
8) Motherboard - The main circuit board in the computer, where the hardware is connected.
9) Graphics card - Used for graphical processing
What is the CPU?
The central processing unit processes all of the data and instructions that make the system work.
What does CPU architecture mean?
The CPU architecture describes the main components of the CPU, how they interact with each other, and with other parts of the computer system.
What three main parts does the CPU contain?
The Control Unit, The Arithmetic Logic Unit and The Cache.
What is The Control Unit?
The control unit is in overall control of the CPU. Its main job is to execute program instructions by following the fetch-decode-execute cycle.
It controls the flow of data inside the CPU and outside the CPU.
What is The Arithmetic Logic Unit?
It does all the calculations.
It does basic operations and comparisons.
It performs logic operations such as AND, OR and NOT and binary shifts.
It contains the accumulator register.
What is The Cache?
It is very fast memory in the CPU.
It stores regularly used data.
What is The Von Neumann architecture?
An architecture describing a system where the CPU runs programs stored in memory. Programs consist of instructions and data which are stored in memory addresses.
What are the 4 main registers?
The program counter.
The memory address register (MAR).
The memory data register (MDR).
The accumulator.
What does The Program Counter do?
Holds the memory address of the instruction for each cycle
What does The MAR do?
Holds any memory address about to be used by the CPU.
What does The MDR do?
Holds the actual data or instruction in use.
What does The Accumulator do?
Stores intermediate results of calculations in the ALU.
Describe the Fetch-Decode-Execute cycle.
FETCH:
1) Copy memory address from The Program Counter to The MAR.
2) Copy the instruction stored in The MAR address to The MDR.
3) Increment The Program Counter to point to the address of the next instruction, ready for the next cycle.
DECODE:
The instruction in The MDR is decoded by The Control Unit. The CU may then prepare for the next step.
EXECUTE:
The instruction is performed.
What is the difference between Volatile and Non-Volatile memory?
Volatile memory is temporary memory. It requires power to retain its data.
Non-Volatile is permanent memory - it keeps its contents even when it has no power.
What is main memory?
Where all data, files and programs are stored while they’re being used.
Explain the concept of virtual memory.
1) Computers have a limited amount of RAM. As applications are opened, RAM fills with data.
2) When RAM is full, the computer needs somewhere else to put application data. It moves data that hasn’t been used recently to a location on secondary storage known as virtual memory.
3) If the CPU needs to read data stored in virtual memory, it must move the data back to RAM. This is very slow as data transfers rates are much slower on secondary storage than RAM
What is ROM?
ROM (‘Read Only Memory’) is non volatile memory , it can be only read to not written to.
It comes on a small, factory made chip built into the motherboard.
It contains all the instructions a computer needs to properly boot up - BIOS (Basic Input Output System)
What three things does CPU performance depend on?
1) Clock speed
2) Number of cores
3) Cache size
How does clock speed affect CPU performance?
This is the number of instructions a single processor core can carry out per second. The more instructions that can be carried out per second, the higher the performance of the CPU.
How does the number of cores affect CPU performance?
Each core in a CPU can process data independently of the rest. The more cores, the more instructions per second, higher performance.
How does Cache size affect CPU performance?
A larger CPU Cache gives the CPU faster access to more data it needs to process.
