1.3 Storage

1.3 Storage

1. Key words

   • Durability
     • How "strong" something is
   • Reliability
     • How consistently something works with out fault
   • Poribility
     • How easily something can be moved around
   • Capacity
     • How much data a storage device can store

2. Secondary storage

   • Purpose: Long term storage of data, files, software, OS (Operating system)
   • Device that is not constantly part of the computer
   • magnetic,optical and solid state

3. Types of storage

   • Optical
     • A laser light creates marks in a pattern on a disk
     • A laser light detects where the marks are and translates this into a readable format
     • Types
       • Blue ray
       • DVD ROM
       • CD ROM
     • Moderatley priced
     • Slow to access data
   • Magnetic
     • Read/write move across the medium and change how magnetised that part of the medium is
     • E.g. one level of magnetised will be a 1, a second will be a 0
     • Types
       • Hard Disk Drive (HDD)
       • Tape Drives
     • Can Store a lot of data
     • Cheap
     • Not very portable
   • Solid state
     • This is made of microchips (Switches)
     • The state of the switches determined if a 1, or 0 is stored
     • Types
       • Solid state drive (SSD)
       • SD Card
       • USB Memory stick
     • Fast to access data
     • Portable
     • Expensive

4. Data sizes

   • GB
     • 1000 Mb
   • KB
     • 1000 Bytes
   • MB
     • 1000 KB
   • Byte
   • Bit
     • 1/8 of a Byte
   • Nibble
     • "Half" a Byte

5. Over Heads

   • 1 Character = 1 byte
   • 10% added to a file size
   • E.g. 2000 bytes + 10% 200 bytes = 2200 bytes