| Compact Flash card (CF) is a type of a data | | | | electrically erased and rewritten. Flash |
| storage device, especially useful for | | | | memory allows multiple memory locations to be |
| portable electronic devices. It can be used | | | | erased or written in one programming |
| directly in a CF card slot with an adapter. | | | | operation. It can thus operate at much higher |
| It makes use of flash memory. Based on | | | | read-access speeds. Better shock resistance |
| physical features, there are two types of | | | | than hard disks is another of its useful |
| Flashcards: Type I (3.3mm thick) and the | | | | feature. Features as these make these cards |
| thicker Type II (CF2) cards (5mm thick). | | | | much more preferable over the others such as |
| | | | battery-powered devices. |
| First produced by SanDisk in 1994, Compact | | | | |
| Flash card is among the first and the oldest | | | | A limitation of this card is that being |
| and also the most successful brands and is | | | | easily rewritable memory, it can be |
| now used for a variety of devices which | | | | overwritten without warning leading to loss |
| includes laptops, portable audio recorders | | | | of data. System failure, power fluctuations, |
| and desktop computers and cameras. | | | | corruption caused by hardware crash or |
| | | | software malfunctions are the other |
| Flash memory devices consume very less power | | | | limitations. |
| and yet have good transfer speeds. They can | | | | |
| also be switched from one system to another. | | | | Flash memory stores one bit of information in |
| They are also designed to adjust to very | | | | an array of transistors, called 'cells'. |
| rapid changes in temperature or in voltage. | | | | Compact Flash Cards are built on the basis of |
| The storage capacity of a Compact Flash card | | | | the type of logic gate used in each storage |
| ranges from 128 MB to about 64 GB. However, | | | | cell and are thus of two types: NOR flash and |
| 256 MB and 2 GB are the most popular choices | | | | NAND flash. Recently however, some flash |
| in Europe. | | | | memory devices called multi-level cell |
| | | | devices, can store more than one bit per |
| Flash memory has a specific quality which | | | | cell. NOR flash cell has two gates: the |
| allows a section of its memory cells to get | | | | Control Gate and the Floating Gate. NAND |
| erased in a single 'flash', very much | | | | Flash has a different mechanism: tunnel |
| reminiscent of a camera flash function. This | | | | injection for writing and tunnel release for |
| reminds one of the ease with which erasure of | | | | erasing. |
| data can be carried out, freeing space for | | | | |
| recording new data onto it. Flash memory | | | | The market demand today is tilting towards |
| being non-volatile and solid state, can be | | | | the lower-priced NAND flash. |