Chapter 2 Flashcards
what is hardware
- physical component that forms part of a computer system
- internal/ external
role of cpu
- storage/ input device -> input data -> processed by CPU -> stored or sent -> output device
- fetches instruction from memory and executes them
motherboard
- hardware components (RAM, CPU) can be connected directly to the motherboard
RAM
- volatile (content of memory is lost if no power to the RAM)
- when full, inactive data removed
- when no more to remove, HDD SSD expand memory
- virtual memory slow (access times)
- when several programs open
ROM
- nOn volatile (permanent)
- small long life battery
- one program (e.g instruction to boost comp)
external hard drive
- common form of secondary storage
- cheap
- non volatile
external hard drives
- USB port
- back up
- expensive
- transfer data
SSD
- non volatile
- flash memory
- fast
- expensive
reasons why a user may want to save data to secondary storage
- make changes to a doc
- keep files for archive for future
- back up
- in a database, each new record saved
what is software
- programs that give instructions to the computer
- program consist of programming code that give instructions ,, cary out task
- e.g. word processing
what does an operating system do
manages hardware
manages communication between hardware and software
how does an OS manage hardware
- allocating memory to software
- sending data and instructions to output devices
- giving each running task a fair share of processor time
device driver
- software in external hardware
- sends customized instructions to that specific component
- e.g ‘print’
What is application software ?
Application software enables the computer to do a particular task, such as word processing
What is system software ?
It is the interface between computer hardware and user application programs
What are the three functions of system software ?
- Allocating memory
- Storage
- Processing time
Describe how the system software deals with processing time ?
Divides processing time into time slices depend on the priority each task is allocated a number of these time slices
What is real time processing and what are some applications ?
- processing of data occurs immediately after it is input and updating occurs before next input occurs
- airline or concert booking systems
What is batch processing and what are some applications ?
- data is collected over a period of time and processed together at a later time
- billing systems, banking systems
What is multi-user system processing and what are some applications ?
- The operating system switches between computers giving each one a ‘time slice’
- database management systems
What is a utility application ?
It is a program that carries out a specific task to assist the operating system
Name three utility applications
- Disc defragmentation
- task scheduling
- data backup and restore
Describe disc defragmentation
rearranges the data on a hard disk so that all the data is stored together and can be quicker to access
Describe a backup
A second copy of a file made and stored on a different storage device
What is an anti virus software ?
Scans files stored on a computer system, looking for viruses
What is the anti-virus software main purpose
detect, locate and remove a virus
What is the main role of the CPU ?
To process programs and data
What does the CU do ?
- decides which instruction to carry out next
- fetches it from memory
- repeats the fetch-execute cycle
What does the ALU do ? (arithmetic logic unit)
- carries out maths equations
What are the 5 registers of the CPU ?
- program counter
- memory address register
- memory data register
- instruction register
- accumulator
What does clock speed mean ?
The number of instructions the CPU can deal with per second
What does the cache do ?
temporarily stores frequently used instructions and data
What is a processor core ?
A core is a single processor
Name 5 computer hardware devices :
- graphics digitizer
- speaker
- mouse
- 3D printer
- Hard disk drive
What is the purpose of a graphics digitizer ?
allows a user to hand draw images. Consists of a flat pad and a stylus
Describe how HD storage media works
uses laser technology to store and retrieve data at high data transfer speed to and from optical disks.
Describe the features of SSD storage:
- It’s flash memory
- usb memory sticks are a type of SSD
- plug and play devices
