Topic 1: Hardware and Communication Flashcards
What is architecture referred to as in CS?
It refers to the components that exists within a computer and how they are interconnected.
What is one architecture?
Von Neumann architectures
Give 3 components which is below the CPU.
- Arithmetic Logic Unit (ALU)
- Register
- Control Unit
Give 4 examples of input.
- Mouse
- Keyboards
- Microphones
- Digital cameras
What is input?
It is any device that introduces data into a computer system from outside it.
Give 3 examples of output devices.
- Printers
- Visual displays
- Speakers
What is an output?
They communicate data beyond the computer system, typically (but not always) to a human user.
Give the function of memory.
Both instructions and data are stored in memory, to be conducted to the CPU as and when they are required.
Give the abbreviation of CPU.
Central Processing Unit
Give the function of a CPU.
It comprises one or more arithmetic logic unit, one or more control unit and any number of registers.
Give the function of ALU.
It performs calculations (e.g. 5 + 2), comparisons (e.g. 5 > 2) and logical operations (e.g. AND, NOT, OR) as instructed by the control unit.
Give the function of a register.
It is a temporary holding area for a small amount of data.
Give 3 types of registers.
- Some registers have a special purpose
- Others have a general purpose
- Key special-purpose registers
What are registers with a special purpose?
They have a clearly defined role such as knowing the memory location of the next instruction.
What are registers with a general purpose?
Their roles are more flexible and can be specified by the programmer.
What does → indicate?
Buses
Give the purpose of buses.
They transfer data between components in the directions indicated.
What do data buses carry?
- Data
- Instructions
What do address buses carry?
Memory locations to be accessed.
What do control buses carry?
Commands to be carried out by the hardware, such as ‘read’ or ‘write’.
What is a memory in CS?
It refers to any storage utilised by a computer system.
Give 4 primary types of memory.
- RAM (Random Access Memory)
- ROM(Read Only Memory)
- Memory cache
- Disk cache
Give another name for RAM.
Main memory
Give the function of RAM.
It is the component of a computer that stores programs that are currently being executed or data that will be needed for immediate use.
Describe RAM.
It is volatile, and contents are lost if the computer loses power.
What does ‘read-only’ mean?
Their contents cannot be changed or deleted.
Why is ROM considered non-volatile?
It is because the contents of ROM are safe when a computer loses power.
What is ROM used for?
To store the bootstrap program, which is needed to start up the computer, as well as any system data that does not change.
Give another name for memory cache.
CPU cache
Describe memory cache.
It is a type of high-speed, smaller-capacity RAM variant, close to the CPU, intended to store commonly used data and instructions.
How can data and instructions be accessed quicker?
It can be accessed quicker when stored in conventional RAM.
What is a disk cache?
It is a specifically designated part of RAM, intended to contain data and instructions from secondary storage likely to be needed either repeatedly or simply next, after the current instruction.
What does a disk cache help with?
Speeds up retrieval of data and instructions.
Give 3 examples of secondary storage.
- Magnetic- internal and external hard disk drives (HDDs)
- Sold-state drives (SSDs) and USB flash drives (pen drives)
- Optical (CD/ DVD’ Blue-Ray) drives
What is secondary storage referred to as?
It refers to any device that can store data, in addition to main memory.
Describe secondary storage devices.
They are non-volatile and are typically high capacity, portable or both.
Give 4 factors which affect the choice of a secondary storage device.
- Speed
- Cost per storage unit
- Durability
- Portability
What does it mean by ‘speed’?
How fast can data be accessed.
What does it mean by ‘cost per storage unit’?
How much does it cost per gigabyte or megabyte.
What does it mean by ‘durability’?
Toughness
What does it mean by portability?
How easy it is to move from one computer to another.
