Storage Devices
Types of Storage Devices
Physical components or materials on which data is stored are called storage media.
Hardware components that read/write to storage media are called storage devices.
Two main categories of storage technology used today are magnetic storage and optical storage.
Primary magnetic storage o Diskettes o Hard disks (both fixed and removable) o High capacity floppy disks o Disk cartridges o Magnetic tape
Primary optical storage o Compact Disk Read Only Memory (CD ROM) o Digital Video Disk Read Only Memory (DVD ROM) o CD Recordable (CD R) o CD Rewritable (CD RW) o Photo CD
Magnetic Storage Devices
Purpose of storage devices à to hold data even when the computer is turned off so the data can be used whenever needed. Storage involves writing data to the medium and reading from the medium. Writing data à recording the data on the surface of the disk where it is stored for later use. Reading data à retrieving data from the surface and transferring it into the computers memory for use.
Diskette drives, hard drives and tape drive all use the same type of medium à use similar techniques for reading/writing data. Surfaces of diskettes and magnetic tape are all coated with a magnetically sensitive material such as iron oxide.
The principle use to store data is that of polarisation – all the ions in the magnetic material align themselves in one direction. Just as a transistor can represent binary
“on” or “off”, the orientation of the magnetic field can be used to represent data. A magnet has one important advantage over a transistor à it can maintain it’s state without a continual supply of electricity.
Surfaces of disks are coated with millions of tiny iron particles so data can be stored on them. Each particle acts as a magnet, taking on a magnetic field when subjected to an electromagnet. The read/write heads of a disk drive contain electromagnets, which generate magnetic fields in the iron on the storage medium as the head
Physical components or materials on which data is stored are called storage media.
Hardware components that read/write to storage media are called storage devices.
Two main categories of storage technology used today are magnetic storage and optical storage.
Primary magnetic storage o Diskettes o Hard disks (both fixed and removable) o High capacity floppy disks o Disk cartridges o Magnetic tape
Primary optical storage o Compact Disk Read Only Memory (CD ROM) o Digital Video Disk Read Only Memory (DVD ROM) o CD Recordable (CD R) o CD Rewritable (CD RW) o Photo CD
Magnetic Storage Devices
Purpose of storage devices à to hold data even when the computer is turned off so the data can be used whenever needed. Storage involves writing data to the medium and reading from the medium. Writing data à recording the data on the surface of the disk where it is stored for later use. Reading data à retrieving data from the surface and transferring it into the computers memory for use.
Diskette drives, hard drives and tape drive all use the same type of medium à use similar techniques for reading/writing data. Surfaces of diskettes and magnetic tape are all coated with a magnetically sensitive material such as iron oxide.
The principle use to store data is that of polarisation – all the ions in the magnetic material align themselves in one direction. Just as a transistor can represent binary
“on” or “off”, the orientation of the magnetic field can be used to represent data. A magnet has one important advantage over a transistor à it can maintain it’s state without a continual supply of electricity.
Surfaces of disks are coated with millions of tiny iron particles so data can be stored on them. Each particle acts as a magnet, taking on a magnetic field when subjected to an electromagnet. The read/write heads of a disk drive contain electromagnets, which generate magnetic fields in the iron on the storage medium as the head