Flashcards
Unit 1.3 Storage Revision
Cards in this deck (16)
- 1What is Secondary Storage?An auxiliary device that is not always connected to power.
- 2Why do we need Secondary Storage?So we don't need to install storage every time we want to use it and to save and backup files and data.
- 3Optical StorageA laser light reads marks in a pattern on a disk and translates into a readable format.
eg. DVD ROM
Reliable - 4MagneticMove across a medium and change how magnetized that area is.
eg. Hard Drive
Cost effective - 5Solid StateMade of switches and and the state determines whether a 0 or a 1 is stored.
eg. USB stick
Flexible - 6Non Volatile and Volatile StorageROM is non volatile and RAM is volatile because ROM doesn't need constant power to store data but RAM does.
- 7CapacityHow much data it can store.
Magnetic has the biggest capacity. - 8SpeedHow fast it can access data.
Solid state is the fastest. - 9PortabilityHow easy it is to move from one place to another.
Solid state is the most portable. - 10DurabilityHow well it can last.
Solid state is the most durable. - 11ReliabilityHow consistently it performs.
Solid state is the most reliable. - 12CostHow much it costs per KB, MB or GB.
Magnetic is the cheapest medium. - 13Size of Text Files1 KB is approximately 1000 bytes.
1 byte per character +10% for any overheads (eg. file type)
eg. - 14Database1. How many bytes in one record
2. Multiply by number of records
3. Add 10% for overheads
Text : 1 byte per character
Integer : 4/8 bytes
Real : 4/8 bytes
Boolean : 1 byte
Date : 8 bytes - 15Image(Number of pixels x number of bytes per pixel) + 10% for overheads
eg. If an image is 1024 x 720 pixels and it has 256 different colours it has 8 bits per pixel because with 8 bits you can have 256 different combinations. - 16SoundbytesPerSample x samples PerSecond x channels x duration
eg. a sound file has 2 bytes per sample, it takes 10 samples per second over 2 channels and is 30 seconds long.
Information
- Description
- Flashcards on Unit 1.3 Storage Revision, created by Karolina Rawdanowicz on 18/12/2017.
- Created by
- Karolina Rawdanowicz
- Views
- 27
- Rating