External storage devices are grouped into
- Magnetic disks
- Optical Devices
- Magnetic tapes
- USB flash drives
2 features of a hard disk
- The main storage device of a computer
- Access speeds are faster than a CD drive
What are internal hard disks used for
-used to permeantly store the operating system, all application software and user data
What are external hard drives used for
- high-storage capacity
- portable devices
- suitable for small-scale backup if data
- can be attached using a USB cable
What does ROM stand for
Read Only Memory
2 features of an optical disk:CD-ROMs
- The disk are supplied with information such as music and software already stored on them
- The user can read data from it but not write on it
What does CD stand for
Compact Disks
3 features of an optical disk:CD-Recordable
- The disks are supplied blank
- The user can only record data onto the disk once
- Data can be read from the disk as often as required
3 features of an optical disk:CD-RW(rewritable)
- The disks are supplied blank
- The user can record data into the disk, erase it and rewrite it many times
- CD-RWs are more expensive the CD-Rs
What does DVD stand for
Digital Versatile Disk
or
Digital Video Disk
2 features of a DVD
- DVD drives can also read CDs
- DVDs are used to store large amounts of data and films
3 features of a blu-ray DVD
- Have a much larger storage capacity than DVDs
- Can be used for recording high-definition television without loss of quality
- Can store digitally encoded video and audio data
What does DAT stand for
Digital Audio Tape
4 features of a Magnetic tape streamer
- A tape streamer reads and writes data stored on magnetic tape-DAT
- Data is stored in blocks and there is a gap between each block
- Transfer of data is slow because magnetic tape uses serial access
- Magnetic tape is an inexpensive way to store large amounts of data
Another name for a USB flash drive
Pen drive
3 features of a USB flash drive
- They are portable devices that use low power consumption
- They work on the principle of ‘plug and play’
- Cost is linked to the capacity of the USB flash drive
What does RAM stand for
Random Access Memory
Features of ROM memory
- It can be read from but not written on
- Programmes stored on ROM are permeant, therefore ROM is non-volatile
- It is used to store ‘booting up’ programme for the windows operating system.
Features of RAM
- It can be read from and written to
- It is volatile
- It is used to hold the current application programs and data that the user is working with
- The size of the RAM can influence the speed of the processor
Define Volatile
The contents of the Memory are lost when the macheine is switched off
Features of Cache Memory
- It can be read from or written to
- It is small in capacity but has faster access speeds
- It’s purpose is to store frequently accessed programmes
Define interface
Allowing communication between the user and the computer
Define Memory management
Allocating internal memory (RAM) to programmes and data that the user is currently using
Define resource management
Controlling peripheral devices and handling user request for peripheral devices
