SD Memory

The Development of SD Memory

            When released in 2003, the SD Memory Card was designed for a fully networked society.  It was a tiny, easy-to-use card offering a host of powerful advantages over memory cards dot designed for networked systems in mind. SD Memory links various kinds of digital equipment through its easy connectivity.  The card is among many that are available now which do not require a personal computer to be one of the devices in the network.  It supports several application formats.  The SD Memory Card has the broad interoperability and compatibility needed to ensure that its applications will continue to expand far into the future.

            Already supported by more than 700 companies around the world, the SD Memory Card is well on its way to becoming the de facto standard memory card for digital connectivity. Since SD memory is universally addressable, this card will provide universal access to an even wider array of multi-media data in the future. The ubiquitous network era is coming, and its key to success is the SD Memory Card.

Specification:

            The SD Memory Card Standard is managed by an industry association (See http://www.sdcard.org/about/memory_card/pls/). SD Stands for Secure Digital.  It is a flash (non-volatile) memory card format developed by Matsushita, SanDisk and Toshiba for use in portable devices, including digital cameras, handheld computers, PDAs and GPS units. SD card capacities range from 8 MB to 32 GB as of 2008.  Sizes less than 128 megabytes are rarely sold in stores, but are used as base memory in inaccessible areas of a device.

            SD cards are based on the older MultiMediaCard (MMC) format.  Listed below are the differences:

            o          To prevent improper insertion, the SD card is asymmetrically shaped.

            o          Most SD cards are physically thicker than MMCs to prevent devices from mating to the wrong type memory.

            O         SD cards generally measure 32 mm × 24 mm × 2.1 mm.

            o          The minimum thickness is 1.4 mm.

            o          The contacts are recessed beneath the surface of the card (like Memory Stick cards), protecting the contacts from contact with the fringes.

            o          Currently SD cards typically have higher data transfer rates, but this may change in the future, particularly in light of recent improvements to the MMC standard.

            On the left side there is optionally a slidable write-protect tab. This tab is designed to prevent data from being over-written accidently. By comparison, MMC has neither notch or write-protect tab.  It is easy to mistake the MMC tab as an electronic on/off switch built inside the card, but it is used simply as a positioning notch switch. In some cases this tab/notch works the same way as the notches on compact audio cassettes and videotape cassette tapes or floppy disks.  In these chips the device senses the tab/notch and determines if the card is write-protected or not.

Low Price Memory Product Availability

            Low Price Memory (www.lowpricememory.co.uk) stocks many memory cards products, along with such products as SanDisk memory products, Sony Ericsson memory, Memory Stick Pro Duo products, SD Memory, SDHC Memory Cards, Compact Flash memory, Micro-SD memory, XD-Picture Cards, USB Memory, USB Pen Drives, Memory Card Readers, Camera Cases for digital cameras, Bluetooth Headsets, PC Memory in a number of formats, Laptop Memory for most portable computers, Sennheiser Headphones, and Camera Batteries.