STORAGE DEVICES
They are devices used to store computer software. It is based on two types of technologies: optics and magnetic. Magnetic is based on the magnetic hysteresis of some materials and other magnetic phenomena, while optics uses the properties of the laser and its high precision to read or write data.
HARD DISK: A hard drive is a storage medium more or less durable. It has magnetic technology. They are common since the 286 came out. A hard disk is composed of numerous discs of material sensitive to magnetic fields, stacked on top of each other; It really looks a lot like a pile of disks without covers and with the turning mechanism and the reading arm included in the housing. Its rotation has such a high speed (about 4,000 rpm), that it is advisable to install a fan for cooling.
DISKETS: As bad and obsolete as a computer is, it always has at least one of these devices. Their capacity is totally insufficient for current needs, but they have the advantage that they have for many years as an absolute standard for portable storage.
Originally the diskettes were flexible and quite large, about 5.25 inches wide. The first capacity of 160 Kb was soon revealed as insufficient, so it started to grow and did not stop until 1.44 Mb, already with the current floppy disks, smaller (3.5 '') more rigid and protected by an eyelash metallic
The floppy drives are compatible "backwards"; that is to say, that in a high density 3.5 "disk drive (1.44 Mb) we can use 720 Kb or 1.44 MB disks, but in an older, double density disk, we can only use them. 720 Kb.
CD-ROM: The word CD-ROM comes from Compact Disc-Read Only Memory. Read-only compact disc. It is an optical support. Information storage system in which the surface of the disk is covered with a material that reflects light. The recording of the data is done by creating microscopic holes that scatter the light (pits) alternating with areas that do reflect it (lands). A laser beam and a photodiode are used to read this information. Its storage capacity is about 650 Mb of information (equivalent to about 74 minutes of recorded sound).
DVD: It is the same as a CD-ROM but has a greater capacity (410 minutes, compared to 74 for a CD). This has only changed the length of the laser, reduced the size of the holes and tightened the grooves to fit more information in the same space.
Flash Memories: These devices are very portable and of small size, every time with the passage of time we see more capacity and smaller size, there are memories from 8gb to 120gb.
Other storage devices:
· Zip (Iomega): They fit 100 Mb and use magnetic technology.
· EZFlyer (SyQuest): They are 230 Mb and have a very high reading speed
· SuperDisk LS-120: They fit 200 Mb and use magneto-optical technology.
· 3.5 "Magneto-optics: They fit from 128 Mb to 640 Mb
· Jaz (Iomega): It's like the Zip and can fit from 1 GB to 2 GB.
· Magnetic Tapes: They fit up to more than 4 GB.