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
