For example, games for Sony's original PlayStation and the PlayStation 2 are backwards-compatible with the latest console, PlayStation 3, but there is no slot for the memory cards used by the older systems. You can also buy adapters that allow you to access these cards through a standard floppy drive, USB port or PCMCIA card slot (available in some laptop computers). Because of these standards, it is easy to use CompactFlash and SmartMedia products in a variety of devices. Because of newer, smaller cards with bigger storage capacities, such as xD-Picture Cards and Secure Digital cards, Toshiba has essentially discontinued the production of SmartMedia cards, so they're now difficult to find.ĬompactFlash cards were developed by Sandisk in 1994, and they're different from SmartMedia cards in two important ways:īoth SmartMedia and CompactFlash, as well as PCMCIA Type I and Type II memory cards, adhere to standards developed by the Personal Computer Memory Card International Association (PCMCIA). This approach means that they are capable of fast, reliable performance while allowing you to specify which data you wish to keep.They are less rugged than other forms of removable solid-state storage, so you should be very careful when handling and storing them. SmartMedia cards erase, write and read memory in small blocks (256- or 512-byte increments). If the notch is on the right side, it requires 3.3 volts. Looking at the card with the electrode facing up, if the notch is on the left side, the card needs 5 volts. A notched corner indicates the power requirements of the SmartMedia card. Power and data is carried by the electrode to the Flash-memory chip when the card is inserted into a device. The OMTP module is glued to a base card to create the actual card. That is why the radio will lose its presets if your car battery dies or the wires are disconnected. Even though you've turned the power off, the car radio is pulling a tiny amount of current to preserve the data in the flash RAM. The difference is that flash RAM has to have some power to maintain its contents, while flash memory will maintain its data without any external source of power. You may think that your car radio has flash memory, since you're able to program the presets and the radio remembers them. Flash memory works much faster than traditional EEPROMs because instead of erasing one byte at a time, it erases a block or the entire chip, and then rewrites it. This erases the targeted area of the chip, which can then be rewritten. Flash memory uses in-circuit wiring to apply the electric field either to the entire chip or to predetermined sections known as blocks. The electrons in the cells of a flash-memory chip can be returned to normal ("1") by the application of an electric field, a higher-voltage charge. In this article, we'll find out how Flash memory works and look at some of the forms it takes and types of devices that use it. To change the value to a 0 requires a curious process called Fowler-Nordheim tunneling. As long as this link is in place, the cell has a value of 1. The floating gate's only link to the row, or wordline, is through the control gate. One of the transistors is known as a floating gate, and the other one is the control gate. The two transistors are separated from each other by a thin oxide layer. It has a grid of columns and rows with a cell that has two transistors at each intersection (see image below). PCMCIA Type I and Type II memory cards (used as solid-state disks in laptops)įlash memory is a type of EEPROM chip, which stands for Electronically Erasable Programmable Read Only Memory.
Memory Stick (most often found in digital cameras).SmartMedia (most often found in digital cameras).CompactFlash (most often found in digital cameras).