Storage Flashcards
Computer storage is divided into
primary, secondary (and offline)
primary storage
directly accessed by the CPU
types of primary storage
RAM, ROM, cache, and registers
types of primary storage
RAM, ROM, cache, and registers
random access memory
used for temporary storage of programs and data currently in used
ram is
volatile - loses content when turned off
read only memory
contains data that can be read but not altered or deleted
rom is
non-volatile - retains data even with no power
secondary storage
External storage devices that are not directly accessed by the CPU
secondary storage includes
SSD and HDD
examples of secondary storage
hard disk, dvd, blu-ray, flash drive
secondary storage is
non-volatile
advantage of secondary storage
- ideal for permanently storing data
- has more capacity
hard disk drives
Operates on magnetic storage principles
Is cost efficient
Has a high storage capacity
Used in computers, laptops, webservers, backup systems for large facilities.
In computers, stores the OS, installed programs and user’s data.
Is read/written using magnetism
Made of a magnetic surface called a platter
The platter is divided into various sectors and tracks that can store a specific number of bytes
solid state drives
Operates on electronic (solid state) principles.
Used in USBs, tablets, and mobile phones.
types of secondary storage
magnetic, optical, solid-state
examples of magnetic
tape, hard-drive, floppy disk
examples of optical
cd, dvd, blu-ray
examples of solid-state
pen drive, flash memory
magnetic
- store data by applying magnetic charge to a magnetised material
- uses platters which are divided
into tracks and sectors. Data is read and written using electromagnets
advantages of magnetic
cheap, fast, hold lots of data
optical
- use light to read and write data. on the disk surface, there are land and pits (highs and lows) that reflect and scatter light
- uses lasers to create and read pits
and lands
features of optical
helpful in long term, low storage capacity, slow
solid state
uses NAND or NOR technology. Transistors are used as control gates
and floating gates
