When we are using a computer, we are often in need of different devices for storing data. This data is stored in digital format. There are two types of data storage, namely primary and secondary (tertiary). This classification is made according to the task performed by the devices. One of the secondary data storage type is the flash memory.
Flash Memory: In Brief
It is primarily used in USB flash drives, memory cards, MP3 players, digital cameras, personal digital assistants (PDA), mobile phones, etc. They can be used for general data storage, at the same time they can also be used to transfer data between computers or other digital products. It uses a specific type of Electrically Erasable Programmable Read Only Memory (EEPROM). The memory can be erased and programmed in large blocks of code. The credit of inventing the flash drive goes to Toshiba.
It is non-volatile i.e. does not need power to maintain stored information (it is also referred to as NAND flash memory). Unlike the hard drive, the flash memory is in solid state. In others, it does not have moving parts. Storing of data takes place on a fixed medium due to which it is durable. It has fast read access time and better kinetic shock resistance.
This is one of the reason why these chips have become very popular in a number of portable devices. They are very hard-wearing, at the same time are able to hold up against intense pressure, extreme temperature, and some of them are able to withstand immersion in water as well. The manufacturers of these storage devices include SanDisk, Kingston, Transcend, Canon, Samsung, Toshiba, Hitachi, etc.
Types of Memory Cards
Secure Digital Card
They are abbreviated as SD cards. They are used in portable devices like digital video recorders, digital cameras, handheld computers, mobile phones, etc. They have been in use since 1999. One can buy the secure digital cards in varying memory capacity. They are currently available between 16 MB to 1 GB storage sizes.
Mini Secure Digital Card
These cards are abbreviated as Mini SD cards and are popularly used in mobile phones. They are smaller than the SD cards. They are available between 16 MB to 256 MB storage sizes.
These are much bigger in size as compared to others. They are also called CF cards. These cards became very popular for digital cameras. The storage capacity ranges from 8 MB to 8 GB, which is convenient for storing a large amount of data. These cards have an advantage over the others, as they have both memory chips and a controller.
These cards were introduced in the market by Toshiba in 1995, however now they have been termed as obsolete for newer devices. The storage capacity of these cards ranges only between 16 MB to 128 MB.