An SD card or a Security Digital card is one which is going to store additional amounts of information for you. It’s used for mobile devices such as cameras and smart phones, for instance and it’s capable of being a life saver in certain situations. However, the type of SD cards that the majority of phones and other mobile solutions like tablets, for instance, are going to use the so called micro SD card. In later years, the mini’s Secure Digital slot was upgraded to support extended capacity SDXC cards up to 1 Terabyte of storage. Mac Mini SD Slot Location Apple is still including an SDXC (and SDHC - SD backward compatible) flash memory card slot on the slimmer aluminum Mac mini systems. Secure Digital (SD) card slot with SDIO for memory cards and accessories; no built-in camera; All models except the Tungsten C, W, and E had Bluetooth while the Tungsten C and TX had built-in Wi-Fi. Wi-Fi is on the T3, T5, and E2 is dependent on the optional the Palm Wi-Fi Card placed in their SD card slot. A Secure Digital (SD) memory card is a digital memory card that utilizes the non-volatile memory card format developed by the SD Card Association (SDA) for use in portable devices. The SD technology is used by more than 400 brands across dozens of product categories and more than 8,000 models. SD Extended Capacity (SDXC™) card is an SD™ memory card based on the SDA 3.0 specification. SDXC capacities range from 64GB to 2TB Default Format: exFAT Because SDXC uses a different file system called exFAT and it works differently than standard SD cards, this format is NOT backwards compatible with host devices that only take SD (128MB to 2GB) or host devices that only take SDHC (4GB to.
History
In 1997, Siemens AG and SanDisk developed the MMC card using Toshiba's NAND-based flash memory. As it uses NAND based flash memory, it is much smaller in size than the IntelNOR-based memory; such as CompactFlash. Originally it used a 1-bit serial interface, but with the new architecture, now it can transfer 4 or 8 bits at a time.
After the release of MMC cards most of the portable music players started using MMC cards as primary storage. But the music industry was skeptical about the use of MMC, as MMCs would allow easy piracy of music. So, Toshiba added encryption hardware in existing MMC and named it Secured Digital or SD card. This allowed Digital Rights Management(DRM) for the music. Matsushita, SanDisk, and Toshiba jointly developed, next generation secure memory card called the SD Memory Card. SD cards provide both an SDMI-compliant (Secure Digital Music Initiative) high-level of copyright protection and high-density memory capacity. Today, in many areas, MMC are being replaced by SD cards. The only reason why some devices continue using MMCs are because of their comparative lower cost than SD cards.
Size
The size of a standard MMC card is 24 mm x 32 mm x 1.4 mm while that of a SD card is 24 mm × 32 mm × 2.1 mm. So from the size comparison, we can see that SD cards are much thicker than the MMC cards, 2.1 mm against 1.4 mm.
Interoperability
Because of the size similarity, MMC cards can be also used in the standard SD card slot, but the reverse is not true.
Storage Capacity
MMCs are currently available in sizes up to 4 GB and 8 GB models. As of September 2007, SD cards were available in sizes from 8 MB to 16 GB. A few companies have announced SD cards with 32 GB also.
Usage
Amongst digital cameras, companies that use SD cards include Canon, Epson, Casio, HP while Epson and some models of Nikon and Sony cameras use a MMC card and compact flash memory depending on the model. In Mobile phones, Nokia uses both MMCs and SD cards which vary according to the model. Samsung and Motorola phones use SD cards. Amongst gaming consoles, Nintendo Wii and Sony Playstation 3 use SD cards while Xbox 360 uses a memory unit.
Different versions
Apart from the standard MMC there are other versions available also. They are Reduced-Size MultiMediaCard (RS-MMC), dual voltage MMC card (DV-MMC), MMC plus, MMC mobile, MMC micro and MMC secure.
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RS-MMC has a size of 24 mm × 18 mm × 1.4 mm. It was released in 2004. RS-MMCs are smaller MMCs and use a mechanical adapter to elongate the card. It can be used in any MMC (or SD) slot and they are currently available in size up to 2 GB.
DV-MMC cards can operate at 1.8 V and the standard 3.3 V. Working at lower voltages reduces the card's power consumption, and thus used in mobile devices. In 2005, version 4.x of the MMC standard launched, to compete with SD card. This version is known as MMCplus (with the full size) and MMCmobile (with reduce size). These cards run at a higher clock speed (26MHz, 52MHz) than the original MMC (20MHz) or SD (25MHz, 50MHz) and it also has 4 or 8 bit wide data buses. Though these cards are fully compatible with MMC standard, but to use it, one needs to update the software.
MMC micro is a micro-size version of MMC and it has a dimension of 14 mm × 12 mm × 1.1 mm, it is smaller and thinner than RS-MMC. It also supports dual voltage, and backward compatible with MMC, and also can be used in full-size MMC and SD slots with a mechanical adapter.
SD cards are normally available in two more versions. They are miniSD and microSD. MicroSD is the smallest memory card available commercially. The size is 15mm × 11mm × 0.7mm. It is about 25% of the size of an SD card. With the help of adapters it can be used in those devices which are meant for SD, miniSD, or Memory Stick Duo cards; but they are not universally compatible.
MiniSD card was launched in 2003 and has ultra-small form factor extension to the SD card standard. These cards were designed especially for mobile phones; and packaged with a miniSD adapter through which it can also be used in devices that equipped with a standard SD Memory Card slot.
SDHC (Secure Digital High Capacity, SD 2.0), an extension of SD card, allows larger capacity, more than 2 GB. It uses the FAT32 file system which supports partition sizes greater than 2 GB. SDHC card has 3 different classes depending on their speed. Class 2 has speed of 2 MB/s, class 4 has 4MB/s, and class 6 has 6 MB /s. SDIO is another standard for SD card, which stands for Secured Digital Input and Output.
Video explaining the various features of SD cards
References
All Windows Mobile Pocket PCs, Pocket PC Phones and Smartphones sold today have some type of onboard flash memory card slot. Though there are card alternatives (such as CompactFlash & MMC) Secure Digital (SD) card slots dominate.
There are several types of Secure Digital Cards available:
Secure Digital Cards - These cards were the first format in the SD class and are still in wide use today. Most Windows Mobile devices have moved to physically smaller versions of the SD card (shown below). Those with older Windows Mobile Pocket PCs and Pocket PC Phones likely use this type of flash memory card. |
Secure Digital High Capacity Cards - A relatively new arrival to the flash memory scene, SDHC cards have the same form factor as standard SD cards, but require SDHC compatible devices in order to be read from and written to. Only a select few of the newest Windows Mobile devices are compatible with the high capacity variety of Secure Digital cards. Look for the SDHC logo (seen left) to verify that a card is, indeed, high capacity. |
mini Secure Digital Cards - Often referred to as miniSD, this format is perhaps the least used in Windows Mobile devices. The miniSD format has been overshadowed by the microSD format (shown below). |
micro Secure Digital Cards - Often referred to as microSD or Transflash cards, this format is in wide use in Windows Mobile Pocket PC Phones and Smartphones. microSD cards are tiny, thin and available in several capacities. |
micro Secure Digital High Capacity Cards - Often referred to as microSDHC cards, this format is the newest in the Secure Digital family and has the same form factor as standard microSD cards. Like SDHC cards, microSDHC cards require special readers and can only be used with compatible devices. Digital cards. Look for the microSDHC logo (seen left) to verify that a card is, indeed, high capacity. |
But... What Sort of Memory?
Although the term 'memory' can be confusing because of its traditional definition in computer jargon, when talking about flash memory cards, the word 'memory' means long-term storage. In this way, flash memory cards are more akin to hard drives than to computer memory, or RAM, which only stores data while it's in use. Flash memory cards are designed for the long-term storage of data on digital cameras, MP3 Players, PDAs, etc.
Flash memory is also called nonvolatile memory, meaning that flash memory does not require any power to retain data. This is also the type of memory used for data storage in modern PDAs, MP3 Players, etc.
How to Use Flash Memory Cards
Adding a flash memory card to your Windows Mobile device does not add memory in the traditional sense (like adding more RAM to a PC). Flash memory cards add more storage space, allowing you to store more applications (software), data files, media files (music, video, photos), etc.
How to Access Data on a Flash Memory Card in Windows Mobile
Using a flash memory card in a Windows Mobile device does not simply add to the internal storage space. Data contained on a flash memory card is accessible as a separate storage location.
With Pocket PCs and Pocket PC Phones (Windows Mobile devices with touchscreens) data stored on a flash memory card is accessible in the File Explorer utility as SD Card, Storage Card or some other name which reflects the type of card being used:
With Windows Mobile Smartphones (non-touchscreen devices), contents of an SD card can be viewed in the File Manager utility.
SDIO
Some Secure Digital (SD), miniSD and microSD peripherals are also available for Windows Mobile Devices. These peripherals are called SDIO (Secure Digital Input/Output) and use the same slot as flash memory cards, but perform hardware functions rather than store data. Examples of SDIO devices include Wi-Fi cards, Barcode Scanners, GPS receivers and more.
Secure Digital Slot
Still Have Questions?
Secure Digital I/o Slot
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