Higher Computing
Solid-State Devices
Features
- Small and contains no moving parts, example include flash cards and USB flash cards(memory stick)
- Both of these types contain the same type of backing storage medium, flash ROM
- Difference between them is that they use different interfaces to connect to a computer or peripheral
Uses
Flash RAM is used where there is a constant supply of power, e.g car radios/ CD-players
Flash ROM is used:
- in ROM BIOS: so that input and output settings can be updated easily
- in Compact Flash and Smartmedia cards, where they are used to store digital camera photographs
- in Memory Sticks on MP3 players
- in the memory cards used for games consoles
Advantages
- Small and makes no noise - fit inside cameras, on key-rings and in watches
- Robust -ideal for wearing and are unaffected by vigorous movement due to no movement parts
- Use less power than hard disk drives
- Replaces floppy disks as they can fit in almost any modern computer
- USB flash memory is used for security applications - one type has fingerprint recognition
Disadvantages
- More expensive, per megabyte of storage, than a hard disk
- Flash chips generally have a limit to the number of times they can be written to, normally between 100k and 300k write cycles
Development trends
- Increased capacity
- Increased read and write speeds
- Reduced physical size
- Lower cost per unit of storage
Increasing interface speeds and wireless communication
Two developments in interfaces are to:
- Increase the speed at which the interface allows the peripheral and computer to communicate
- Allow wireless communication between the peripherals and the CPU. For example using WiFi and Bluetooth