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| - reduced by removing the external address and data bus circuitry. Instead, external devices could communicate with NAND flash via sequential-accessed command and data registers, which would internally retrieve and output the necessary data. This design choice made random-access of NAND flash memory impossible, but the goal of NAND flash was to replace hard disks, not to replace ROMs.
- Flash memory (also called a flash card) is
- A type of memory that is non-volatile (capable of retaining its contents when power is removed). In music synthesizers, flash memory is often used in memory cards that provide external patch or waveform storage; compared to floppy or removable disks, they have the virtue of having no moving parts and being immune to ereasure magnetic fields. Early types of flash memory could only be written to a limited number of times, but newer designs have increased the limit enough so that it no longer matters. Flash is also used in some synths for operating system storage; doing so allows for the owner to upgrade the operating system without having to change hardware or take the synth to a tech for service.
- Flash memory is a non-volatile computer storage chip that can be electrically erased and reprogrammed. It is primarily used in memory cards, USB flash drives, MP3 players and solid-state drives for general storage and transfer of data between computers and other digital products. It is a specific type of EEPROM (electrically erasable programmable read-only memory) that is erased and programmed in large blocks; in early flash the entire chip had to be erased at once. Flash memory costs far less than byte-programmable EEPROM and therefore has become the dominant technology wherever a significant amount of non-volatile, solid state storage is needed. Example applications include PDAs (personal digital assistants), laptop computers, digital audio players, digital cameras and mobile phones. It
- Flash Memory is a type of erasable ROM intended for use as Mass Storage. For note, ever since The Eighties there's virtually no ROM chips produced that cannot be somehow erased and rewritten. It's just that most of them could be only erased as a whole: either by exposure to the UV light or by the high voltage pulse. After erasing the chip could be written to, quite similar to the normal RAM, but it will hold the information after the power would be switched off. This technique of erasing and writing is commonly called "flashing" in the technical lingo, a rudiment of the "ancient" times when ROM chips were written by burning the specific connections inside them by these pulses. Flash memory takes its name from this process, but differs from these early chips by the simple fact that it can b
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| abstract
| - Flash memory is a non-volatile computer storage chip that can be electrically erased and reprogrammed. It is primarily used in memory cards, USB flash drives, MP3 players and solid-state drives for general storage and transfer of data between computers and other digital products. It is a specific type of EEPROM (electrically erasable programmable read-only memory) that is erased and programmed in large blocks; in early flash the entire chip had to be erased at once. Flash memory costs far less than byte-programmable EEPROM and therefore has become the dominant technology wherever a significant amount of non-volatile, solid state storage is needed. Example applications include PDAs (personal digital assistants), laptop computers, digital audio players, digital cameras and mobile phones. It has also gained popularity in console video game hardware, where it is often used instead of EEPROMs or battery-powered static RAM (SRAM) for game save data. Flash memory is non-volatile, meaning no power is needed to maintain the information stored in the chip. In addition, flash memory offers fast read access times (although not as fast as volatile DRAM memory used for main memory in PCs) and better kinetic shock resistance than hard disks. These characteristics explain the popularity of flash memory in portable devices. Another feature of flash memory is that when packaged in a "memory card," it is extremely durable, being able to withstand intense pressure, extremes of temperature, and even immersion in water. Although technically a type of EEPROM, the term "EEPROM" is generally used to refer specifically to non-flash EEPROM which is erasable in small blocks, typically bytes. Because erase cycles are slow, the large block sizes used in flash memory erasing give it a significant speed advantage over old-style EEPROM when writing large amounts of data
- reduced by removing the external address and data bus circuitry. Instead, external devices could communicate with NAND flash via sequential-accessed command and data registers, which would internally retrieve and output the necessary data. This design choice made random-access of NAND flash memory impossible, but the goal of NAND flash was to replace hard disks, not to replace ROMs.
- Flash Memory is a type of erasable ROM intended for use as Mass Storage. For note, ever since The Eighties there's virtually no ROM chips produced that cannot be somehow erased and rewritten. It's just that most of them could be only erased as a whole: either by exposure to the UV light or by the high voltage pulse. After erasing the chip could be written to, quite similar to the normal RAM, but it will hold the information after the power would be switched off. This technique of erasing and writing is commonly called "flashing" in the technical lingo, a rudiment of the "ancient" times when ROM chips were written by burning the specific connections inside them by these pulses. Flash memory takes its name from this process, but differs from these early chips by the simple fact that it can be "flashed" only partially, leaving other parts of the chip untouched. It is also structured much like the common DRAM chips, using capacitors to store the data, though they are designed differently from the capacitors in the DRAM, and are able to hold the informations for years. This means that it can be read and written quite similarly, so it is much faster than the older magnetic or optical drives, and as it has no moving parts, these devices are much more durable and they also require little physical space, electrical power, or cooling. Because, unlike a hard drive, flash memory has no seek time, flash media deals much better with data fragmentation. Not all things are great in flash land, though. When the chip is "empty", data can be read and written to any part of at random and without causing hardly any fatigue, but it is the erasing part that causes much of its problems. While flash chips can be erased partially, it must be done in blocks, by using high-voltage pulses to reinitialize the capacitors in the whole sections of the chip, commonly called "pages". It is this sectional nature that means that Flash cannot be used as a normal non-volatile RAM similar to core, and that they need to have additional controller chips or built-in circuits to handle the erasing and addressing, and that makes them more similar to disk drives in actual usage. To add an injury to the insult, the high voltage needed to erase the flash memory degrades the structure of the semiconductor itself, so it wears out much faster than most other types of Mass Storage, making flash (much like CD/DVD-RW discs) generally unsuitable for use as RAM, and as writing data to it is generally slower than reading (if the chip is full and needs erasing first -- much slower) it is also cannot be used as a boot volume, which usually need much to be written on. Finally, because it's a semiconductor chip and requires complex and expensive tools to manufacture, flash memory is closer to the DRAM in the cost, and thus is still enormously expensive compared to magnetic and optical storage, rather severely limiting its usefulness in Real Life. Things are getting better, but SSDs still cost about ten times more than good old HDDs of similar capacity. And the USB thumb drives can look very cute.
* Solid State Drives are the HDD-sized devices that hold quite a few Flash chips and are roughly similar in capacity to the modern HDDs. They are usually marketed as direct replacements for hard drives for people that prefer their speed and indifference to the rough handling, and are not afraid of their price, small sizes, and the whole "fatigue" thing, so they are typically found in standard laptop HDD sizes, and use the common HDD IDE or SATA interfaces. Slightly easing the "fatigue anxiety", though, modern SSDs have roughly the same mean time between failures as the modern hard drives. On the other hands, they're still much more expensive. Nintendo's Wii has a rather small 512MB SSD instead of its competitors' multigigabyte hard drives. To offset the cost problem, it's common for homebuilt PCs to have a relatively small SSD to hold key programs (including the operating system) and one or more larger HDDs for general storage.
* Thumb Drives are rather similar, differing only in that they have smaller size (only slightly larger than the plug -- typically male USB -- they are integrated with) and capacity, and generally aren't designed to be the main system volume, but intended to to replace removable media, similar to the early Floppy Disks. They usually use not the internal HDD interface, like the SSDs, but one of the common outside buses like USB. Most (but not all) thumb drives contain flash memory. This is usually permanent, but upgradeable ones instead contain flash readers that take a standard flash card.
* And then there's the USB bracelet.
* And USB Flash watches, James Bond style! Some Swiss Army knives come with a USB drive attachment as well.
* Flash Cards are simply boards with flash chips and the minimum number of support chips needed to make the memory work all squeezed into a standard-sized Cartridge. Numerous formats are available, with varying degrees of physical and logical compatibility, in approximately chronological order:
* Numerous game consoles use proprietary memory card formats to save game progress between play sessions separately from the game itself. Since consoles don't use rewriteable optical drives, this became pretty much mandatory once games started coming on optical disc instead of magnetic disk or cartridge.
* Several flash card standards have a rather bizarre origins from the laptop extension buses that make them somewhat similar to modern SSDs
* PCMCIA, first of them, was originally a laptop memory card format, based on a pin-reduced version of the good, ol' ISA (technically, on its hard-drive subset, the IDE interface) bus. Later it became "PC Card" and explicitly started allowing IDE drives and other peripherals. Has 68 pins compared to the 16-bit ISA's 100.
* Its successor, CardBus, is commonly called "PCI for laptops", as it could switch back and forth between ISA/IDE and PCI modes on-the-fly. Also 68 pins.
* CompactFlash is a tiny version of PCMCIA and is electrically compatible with IDE, requiring only a pin converter. Has 50 pins.
* PCMCIA's successor, ExpressCard, is based on PCI Express and USB, and is being used for some truly enormous flash cards that are basically a whole bunch of readers for other formats squeezed into one card. 26 pins.
* The SIM cards in many cellphones are used as their primary (sometimes ONLY) mass storage device
* MMC (MultiMediaCard,) RS-MMC and MMCmicro.
* SD (Secure Digital,) miniSD and microSD are an updated version of MMC.
* xD Picture Cards, a variant developed by Olympus and Fujifilm specifically for digital cameras. (Currently being phased out in favor of the better-supported SD format.)
* Memory Stick and Memory Stick PRO/PRO Duo/Micro are Sony's proprietary format.
* Some MP3 players, particularly smaller ones, have built-in flash memory. Likewise many digital cameras and an increasing number of DV cameras.
- Flash memory (also called a flash card) is
- A type of memory that is non-volatile (capable of retaining its contents when power is removed). In music synthesizers, flash memory is often used in memory cards that provide external patch or waveform storage; compared to floppy or removable disks, they have the virtue of having no moving parts and being immune to ereasure magnetic fields. Early types of flash memory could only be written to a limited number of times, but newer designs have increased the limit enough so that it no longer matters. Flash is also used in some synths for operating system storage; doing so allows for the owner to upgrade the operating system without having to change hardware or take the synth to a tech for service.
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![[RDF Data]](/fct/images/sw-rdf-blue.png)