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Q. I notice labels like “Class 2” and “Class 4” on Secure Digital memory cards. What do these mean?

A. The class rating specified on the Secure Digital card refers to the minimum sustained speed at which the card can continuously record video data. While this may not mean much for snapping random pictures, the sustained transfer rate is more important for camcorders and cameras that can shoot movie clips.

The number in class rating — commonly Class 2, Class 4, Class 6 or, recently, Class 10 — refers to the rate of megabytes transferred.

For example, a Class 2 card moves a minimum of two megabytes of data per second, while a Class 10 card can transfer a minimum of 10 megabytes per second. (The SD Card Association has the technical details on class ratings at www.sdcard.org/developers/tech/speed_class.)

Depending on the camera and its own specifications, using a card with a lower rating when trying to shoot high-definition video could result in error messages, dropped frames and uneven playback. Check the manual for your camera or camcorder to see what cards are recommended for your model; for high-definition video, a Class 4 card or higher may be required.

The class rating is separate from the card’s speed rating, which is also printed somewhere on the packaging or label. The speed rating looks something like “up to 15MB/s Read, 9MB/s Write” in the card’s fine print.

These numbers refer to the maximum transfer speed for data being read and written to the card. Read speed (in this case, 15 megabytes per second) is the amount of time it takes to transfer photos and videos from memory card to computer. Write speed (9 megabytes per second in this example) refers to how quickly data can be recorded onto the card from the camera.

Like class ratings, memory-card speed ratings may not matter as much for casual photography with point-and-shoot cameras.

Cards with faster speed ratings are sometimes recommended for digital S.L.R. cameras that can shoot high-resolution pictures in continuous bursts.

Review by Mobilitysite Reviews – Zealot

I still remember my first computer storage device, an external hard drive for a Mac Plus. It was the size of a small VCR, held 20MB and it seemed like it was more storage then anyone would ever need until the end of time.

This last week I have been testing a SanDisk 16GB MicroSD card, kindly provided by our friends at SanDisk. Where once I was so impressed by 20MB the size of a bread box, I now take the fact that 16,000MB can be held on a card smaller then my fingernail to be commonplace. We have certainly come a long way in terms of solid state data storage and SanDisk has consistently innovated and is still one of the companies creating and pushing advances in NAND technology.

The MicroSDHC format is now widely accepted through out the mobile industry, and it’s small size and infinitesimal weight make the format perfect for mobile phones and other small handheld devices. Originally called TransFlash and developed by SanDisk (I still have one of their earliest 32MB models), these memory cards and the NAND tech behind them make devices such as smartphones possible.

So how does the new 16GB MicroSDHC card from SanDisk stand up to it’s noble ancestors? Quite well, to be sure. The card I tested is Class 2, meaning it must have a minimum write speed of 2MB. As you will be able to see from the speed tests below, conducted using Flash Memory Toolkit 1.2 and a SanDisk MobileMate card reader, the 16GB MicroSDHC far exceeds the minimums for it’s class.

Above are the read/write speeds for the SanDisk 16GB MicroSDHC Card. All in all quite impressive considering that this is a Class 2 card which requires a minimum of 2000K a second write speed. This card well surpasses the minimums, with an average write speed of 5349 KB/s.

Above are the read/write speeds for the SanDisk 8GB Ultra MicroSDHC card. As can be expected, write speeds are much faster for the Ultra card which is a class 8, meaning a minimum of 8000k a second write speed. However, I was impressed that the read speeds are more or less consistent for the 8GB Ultra and 16GB cards. In fact, the 16GB reads a little bit faster then it’s smaller, class 8 cousin.

This may be a fairer test of the 16GB card’s speed. Above are the speeds for another class 2 card, a 2GB DaneElec MicroSD. Clearly inferior to both the 16GB and 8GB Ultra cards, save for read speeds on the larger files. Write speeds however are slower across the board though still over the minimums, with an average of 3746 KB/s, one and a half MB slower then the 16GB Class 2 SanDisk card.

Lastly just for context I tested a standard 4GB flash drive. about 2 years old. It’s read speeds are consistent with the MicroSD cards but the write speed is horrible.

The SanDisk 16GB MicroSDHC card should serve any purpose that requires large amounts of data storage, such as watching video on a smartphone. I would suggest that a faster card with a higher class, such as Class 6 or Class 8 may be more suitable if you need very rapid access or paging, but you certainly can’t go wrong with this Class 2 card for general use. SanDisk has always made quality memory products and this card is no exception. I can give it a solid recommendation.

“We help you select the right memory card for your digital camera, MP3 player or mobile phone” By PC World Staff

With video, image and data files becoming larger thanks to better quality media, the importance of making sure you have adequate storage is only going to increase this year and beyond. Portable devices such as digital cameras, mobile phones and portable multimedia players often use removable memory cards to store data, so getting the right one is important.

A common mistake is to not budget for an extra memory card when purchasing a device such as a digital camera or mobile phone. Although some devices don’t offer extra storage via a memory card slot, many do, so it’s important to check this when buying a new device. With a variety of memory cards available on the market, purchasing the right one can be a confusing task. Let’s help you to work out what you need!

What device?

The best starting point is to check whether your device has a memory card slot. Depending on the brand and type of unit, the memory card required can differ (examples include SD, CompactFlash, microSD, miniSD).

If the device doesn’t have a memory card slot then it will often have a large amount of internal storage. For example, the Apple iPhone 3GS is available in 16GB and 32GB variants, and it doesn’t have a storage slot. The most common devices that use memory cards are digital cameras, mobile phones and portable media players.

Digital cameras

The most common memory card used by compact digital cameras is an SD (Secure Digital) card. An SD card is about the size of a postage stamp and is used by almost all digital cameras, with the exception of Sony models and most Olympus cameras. The largest capacity SD card available is 4GB, though newer SDHC (Secure Digital High Capacity) cards can be bought. The most popular SDHC cards are 8GB in size, but 16GB and 32GB cards are available; 64GB cards will soon hit the market.

Although SDHC cards have the same form factor as regular SD cards, a number of older devices may experience compatibility issues. Before buying an SDHC card, be sure to check that the device you are using it in supports the SDHC format.

For older Olympus and FujiFilm cameras, you’ll need an xD (Extreme Digital) Picture Card. xD cards have a smaller form factor than SD cards, so they won’t fit in an SD card slot and vice versa. xD cards can theoretically have a capacity of up to 4GB, though there are currently no cards over 2GB available on the market. As xD is a proprietary storage solution, xD cards are generally more expensive than their SD counterparts.

Sony cameras require a Memory Stick, which is another proprietary storage solution. Memory Sticks are available in a number of varieties including Memory Stick PRO, which offers higher storage capacities, Memory Stick Duo and PRO Duo, a smaller form factor version of the card, and Memory Stick PRO-HG, a high speed version of the PRO designed for use in high-definition video cameras. The largest capacity Memory Stick currently available is 16GB, though the maximum theoretical capacity according to Sony is 2TB. Memory Sticks are compatible only with Sony branded products and, like xD cards, are generally more expensive than SD cards.

In digital SLR (Single Lens Reflex) cameras, the most common form of memory card storage is CompactFlash (CF) cards – although SD cards are slowly gaining ground in digital SLR cameras. Many newer digital SLR camera models contain both SD card and CompactFlash slots, while other models may only have an SD card slot. CompactFlash cards are widely regarded as more durable than other, smaller memory cards, hence their use in SLR cameras, which are mainly used by professional photographers. The largest CF card available has a capacity of 64GB.

Mobile phones

microSD, formerly known as TransFlash, is the most common memory card used by mobile phones. It’s a favoured format for mobile phones due to its compact size – it’s not much larger than a fingernail. Currently, the highest capacity microSD card available is 8GB, though this is the SDHC variant. As mentioned in relation to SD cards, any microSD card over 4GB in capacity is microSDHC, and these larger capacity cards may not work with all devices. Generally, Nokia, Samsung, Motorola, LG and BlackBerry mobile phones all use the microSD card format. miniSD cards may be found in some mobile phones, though this is rarely the case with newer models.

For Sony Ericsson phones, removable storage comes in the form of Memory Stick Micro (M2) cards. M2 cards are essentially a smaller sized version of the Memory Stick, and are available in capacities of up to 8GB (though 32GB is the theoretical maximum capacity). Some newer Sony Ericsson phones use microSD cards rather than the proprietary Sony M2 cards.

Video Cameras

SD cards are one of the most popular storage formats for video camcorders. Some video cameras can record video directly onto an SD card. Others will record video to the camcorder’s built-in hard disk drive or disc, using the SD card memory to store still images. Like Sony digital cameras and Sony Ericsson mobile phones, Sony handycams use the proprietary Memory Stick format, and some JVC camcorders use microSD cards rather than SD.

Other devices

Many other devices also use memory cards. Portable music and media players may have a memory card slot, often in addition to built-in flash memory or hard disk drives. Depending on the brand of media player, the player may support either SD or microSD cards – though many of the newer players will support the SDHC and microSDHC formats for larger capacity cards.

Portable GPS devices commonly store maps on SD cards. A growing number of GPS devices also include multimedia features such as picture viewers and music players and these files may be stored on SD cards for playback through the GPS unit.

Although PDAs (Personal Digital Assistants) aren’t as popular as they once were, there are still a number of models available on the market. Most of them use SD cards, though some use microSD to keep the unit smaller.

Memory card adapters

An important consideration when using the smaller variants of memory cards is a memory card adapter. For example, when using microSD cards, an adapter allows the microSD card to slot into a regular SD slot. This also means you can use your microSD card in the SD card slots found on many PC and notebook computers – making file transfers easier.

Capacity

No matter the kind of device you use, be sure to consider the amount of data you will need to store at any one time on the device and purchase a memory card with adequate storage.

Shopping Checklist: Memory Cards

• Compatibility

Ensure the memory card you’re buying is the right one for your device. If you are buying a high capacity card, such as an SDHC card, ensure that the device you will be using the card in supports format. While an SDHC card will fit into a regular SD slot, some devices don’t support the higher capacity format.

• Capacity

Consider the amount of data you will need to store at any one time and purchase a memory card with an appropriate storage capacity. If you regularly delete or upload data to a PC, then a high capacity memory card may not be needed. On the other hand, if you travel regularly or need a card to store music and video on, then a larger capacity model may be a smart choice.

• Adapter

If you are using a smaller card, for example a microSD or Memory Stick M2, make sure you purchase an adapter that will allow you to use these cards in a regular SD or Memory Stick slot. Often these adapters are bundled with the cards when purchased, but sometimes they are sold separately.

• Card reader

A memory card reader lets you access the files on a flash memory card and may be handy if you have multiple types of card. There are many variants of card readers, but almost all of them connect via USB, making them easy to slot into a USB port on a PC or notebook computer. There are single card readers that can only read a single memory type, (for example SD), and multiple card readers that can read many memory card formats, including SD, SDHC, miniSD and Memory Stick. These are often called 3-in-1, 4-in-1 or 5-in-1 card readers, depending on the number of types of card they can read.

• Speed

Memory cards offer a variety of data transfer speeds. For the average consumer, this isn’t a big concern. But for professional photographers, for example, it can make a difference to image capture and transfer rates. Many new cards claim fast transfer speeds – some claim read and write speeds of up to 20MB per second. If this is important, then do consider the speed of the card before purchase.

• Software

Many memory card vendors package software specially developed for the cards. This can include image rescue software for use in cards for digital cameras, for example, or tools to recover accidentally erased or deleted files. The software is sometimes included on the cards, but usually just included in the sales package.

• Video

Many memory card manufacturers have developed cards specifically for video recording. For example, SanDisk offers a Video HD SDHC card, which it claims is ideal for recording high-definition video content from the latest range of HD camcorders.

• Write protection tab

Some SD cards have a sliding write protection tab, preventing the accidental loss of data. Sliding the tab forward means the card can’t be written to; that is, any content on the card can’t be removed nor can new content be loaded onto it. The write protection tab isn’t a feature of smaller memory cards, such as microSD or miniSD cards.

• Accessories

Many memory card vendors provide accessories in the sales package. These can include a card adapter, cases or even a USB card reader. Although these accessories generally aren’t expensive, buying them together in single package can save you some extra dollars.

• Multiple devices

If you own multiple devices with the same memory card slot, for example a digital still camera and a digital video camera that both use SD cards, sharing a single SD card between two devices can save you some money if you’re on a budget.

Jargon Buster: Memory Cards

CF: CompactFlash. The most common cards found in SLR cameras, though slowly being replaced by SD. Widely regarded as more durable than smaller memory cards such as SD.

HC: High capacity. A higher capacity card than regular SD and microSD cards. Note that SDHC and microSDHC cards generally aren’t compatible with regular SD card slots.

M2: Memory Stick Micro. A smaller version of the Memory Stick used in Sony Ericsson mobile phones. It is a proprietary memory card format developed by Sony for use in its products.

Memory Stick: A proprietary memory card format developed by Sony for use in its products. Mainly used in Sony’s Cyber-shot cameras, Handycam video cameras and the PSP (PlayStation Portable) gaming device.

microSD: micro Secure Digital. A flash memory card about the size of a small fingernail. Primarily used in mobile phones.

miniSD: mini Secure Digital. A flash memory card with smaller dimensions than a regular SD card. miniSD cards were previously used in mobile phones, although they have now been replaced by microSD cards.

MMC: Multimedia Card. This is a flash memory card that is the same size as an SD card. They have been superseded by SD cards.

SD: Secure Digital is a flash memory card format approximately the size of a postage stamp. SD cards are commonly used in digital cameras.

SLR: Single Lens Reflex cameras are mainly used by professional photographers and offer an array of manual camera options. They use an automatic mirror system to direct light from the lens to the viewfinder.

xD: Extreme Digital Picture Card is a memory card format developed by Olympus and FujiFilm for use in their digital cameras.

FAQs: Memory Cards

Q: What capacity memory card should I buy for my digital camera?

A: This depends on a number of factors, including the megapixel count of your camera and how many photos you need to store on the card at any one time. If you plan to travel and won’t have frequent access to a computer then the bigger the capacity, the better. However, as long as you regularly upload your photos, then a card with a huge capacity isn’t always required. Most people can get by with a 2GB or 4GB card, though obviously a larger capacity card allows you to take more snaps at the highest a resolution possible.

Q. Why are xD cards and Memory Sticks more expensive than SD cards?

A. Both xD and Memory Stick are proprietary storage solutions, hence the more expensive price-tag – they can often cost three times the price of a comparable SD card for example. Previously, memory cards could be pricey but the increased demand for portable storage solutions has seen the cost of most memory cards drop considerably in the past 24 months. Generally you can pick up a 2GB SD card for less than $20.

Q. How important is the speed of a memory card?

A. The memory card speed is important for professional photographers and videographers, but most consumers using a basic point-and-shoot camera won’t need to be concerned by a card’s read and write speed. Generally memory cards with a fast read and write speed will allow a photographer to take more pictures in less time, for example, which should improve their workflow.

Q. Why are CompactFlash (CF) cards often a preferred choice for memory cards in D-SLR cameras?

A. CompactFlash cards are widely regarded as being more durable than the smaller SD counterparts, largely due to their sturdier, larger and thicker design. This means they are valued by professional photographers. Some recent D-SLR cameras are shipping with both CF and SD card slots, though SD cards are becoming more popular.

Q. What microSD card storage size is best for my mobile phone?

A. This depends on what features your phone has and how often you intend to use them. For example if your phone has a camera, a video recorder and can play MP3 files – and you commonly use these functions – then a microSD card with a 4GB capacity or greater would be a good choice.

Q. What is the difference between an SD and an SDHC card?

A. SDHC memory is a high capacity version (8GB and above) of the SD format. A SDHC memory card has the same physical characteristics as a regular SD card, so an SDHC card will always fit into an SD memory card slot. However, it’s important to note that some SDHC cards won’t be compatible with older devices due to the difference in format.

Q. What is the difference between a microSD and microSDHC card?

A. microSDHC memory is a high capacity version (8GB and above) of the microSD format. A microSDHC memory card has the same physical characteristics as a regular microSD card, so a microSDHC card will always fit into a microSD memory card slot. However, it’s important to note that some microSDHC cards won’t be compatible with older devices due to the difference in format.

Q. What is a memory card reader?

A. A memory card reader is a device that plugs into a USB port on any notebook computer or PC and allows you to plug in a memory card. This lets you to upload your multimedia content from the card to the hard drive of the PC for backup or storage. Card readers come in various shapes and sizes and support a range of different memory cards. Most notebook computers and some multimedia PCs have card readers built into them.

Q. What is a memory card adapter?

A. A memory card adapter is a device that allows smaller sized cards to use the slot of larger sized cards. For example, a microSD to SD adapter allows the microSD card to fit into a regular SD slot. This means you can use your smaller microSD card in the larger SD card slots found on many PC and notebook computers – making it easier to transfer your files.

USB Flash Drive

The USB, Universal Serial Bus, Flash Drive was introduced as an alternative to floppy disks with the advantage of being more reliable, more durable, much faster and with much larger storage capacity. Today the USB Flash Drives have completely replaced the aging floppy disks. Since they are mostly used to store and transfer digital files between computers the USB Flash Drives are seen as a complement to memory cards. Facts like size and lack of USB interface on small portable devices contribute also to the fact of not being a competitive storage format to memory cards.

Considering that every new desktop computer, laptop computer and printer has at least one USB interface the USB Flash Drive standard is the most compatible flash memory device for transferring digital files to and from a computer.

Since USB Flash Drives do not have a standardized form factor they can be found in many different sizes and designs, but in general they are no bigger than a lighter or a pack of gum. The same applies for the USB Flash Drive as a name, since it is not a standardized trademark it can be fund under many names. Such as Jump Drive, Pocket Drive and Pen Drive, still the USB Flash Drive name is the most common used when referring to USB based flash memory devices.

USB Flash Drives can be found with two different data transfer speeds. The USB 1.1 standard has a transfer speed of 1.5 MB/sec or 8 X and the USB 2.0 has a transfer speed of 60 MB/sec or 400 X. The speed of the USB 2.0 is the fastest in the memory card industry.

SmartMedia Card

SmartMedia Card was introduced in 1996 by Toshiba Corporation and was originally called SSFDC, for Solid State Floppy Disk Card. It looks like a miniature floppy disk and has about one third the size of a credit card. Since SmartMedia Card does not incorporate a controller chip makes it the thinnest, only 0.76 mm, and among the lightest flash memory cards available.

The lack of high storage capacity, max 128 MB, and the form factor are the reasons that SmartMedia Card is more or less phased out of the market. In 2002 the xD-Picture Card was introduced as the SmartMedia Card’s successor. Still SmartMedia Cards can be purchased, but very few new electronic devices are compatible to them, and are only manufactured by Samsung and Toshiba. They are used mainly in older digital cameras, primarily manufactured by Fuji, Olympus, Ricoh, Samsung, Toshiba, and for industrial use.

There are two versions of SmartMedia Cards which are having different operating voltage. SmartMedia Cards can be found in either 3.3V or 5V. Since not all electronic devices support both 3.3 and 5 volt it is better to make sure that you select a card with the right operating voltage, otherwise your memory card will not work. The electronic device’s operating voltage can be found in its manual. Determining the operating voltage of a SmartMedia Card is simple. In cases the operating voltage is not indicated on the card you have to look at the top corners of the card. A notched top corner on the left side, when facing the front of the card, indicates a 5 volt card. A notched top corner on the right side, when facing the front of the card, indicates a 3.3 volt card.

The SmartMedia Card is supporting write protection but not with a switch that can be found in xD-Picture Card. For protecting the SmartMedia Card’s content from being erased or overwritten by accident, you need to put a sticker on the card’s write protect pad. The SmartMedia Card’s write protect pad is the circle that can be found in the middle of the card, when facing the front of the card.

xD-Picture Card

The xD-Picture Card was introduced in 2002 by Fuji Film and Olympus as a replacement to the older SmartMedia Card. It is produced exclusively by Toshiba and can be found branded only under the name of Fuji Film and Olympus.

The xD-Picture Card format was developed to be used by digital cameras and is more or less used by Fuji Film and Olympus digital cameras. Like SmartMedia Card, the xD-Picture Card does not incorporate a controller chip which allows it to have small form factor but at the same time making it dependable to the host device’s controller chip.

This memory card is not that popular by digital camera manufactures since they have to incorporate the controller chip into the electronic device, which adds costs and volume. In 2005 a new version of xD-Picture Card was introduced called Type M. The main difference is the uses of Multi-Level Cell technology in contrast to the Single-Level Cell technology that standard xD-Picture Cards are using. This makes the xD-Picture Card Type M less expensive in exchange of being less high performance inform of lower transfer speed (read up to 4 MB/sec and write up to 2.5 MB/sec), lower cell endurance and higher power consumption.

In late 2005 another version of the xD-Picture Card was introduced, Type H, offering higher transfer speeds. Type H is 2 to 3 times faster than the standard or Type M version, the exact transfer speed depends on the digital camera. In most of the cases the different versions of the xD-Picture Card are compatible with each other, but not always. We recommend you to look at the digital camera’s manual if you want to find out the versions that your digital camera is compatible with.

Some memory card readers may require firmware upgrades for the newly introduced Type M card, otherwise they will not be able to work with the memory card. Fuji Film branded xD-Picture Cards do not support the panoramic mode that can be found on Olympus digital cameras. For being able to use that feature you will need an Olympus branded xD-Picture Card.

CompactFlash Type I & II

CompactFlash was introduced in 1994 by SanDisk Corp as a smaller alternative to the PCMCIA / PC card. CompactFlash was the second small form factor memory card based on the flash memory technology and has one-forth the volume of the PC Card.

CompactFlash can be found in two physical sizes, type I and II. Both types have the same dimensions except in thickness, type I is 3.3 mm thick and the type II is 5 mm thick. The CompactFlash Type I is the most common used and can also be used in type II slots but not vice versa. Since Type II is bigger in volume than Type I it allows it to have higher storage capacity.

Since CompactFlash has the second biggest form factor, after PC Card, in the memory card industry, about the size of a matchbox, it is not able to be used in many small portable devices like mobile phones and digital audio players. CompactFlash is mostly employed by professional digital cameras, due to the high storage capacity, high data transfer speed and low price per megabyte. It is expected that CompactFlash will lose in popularity to smaller memory card standards and will evidently have the same fate as the PC Card standard.

The chassis of the CompactFlash, mostly the Type I, is also used to host expansion modules with Wi-Fi, ethernet, digital camera and other capabilities. The chassis of the CompactFlash Type II is used to host the MicroDrive memory card standard which, in contrast to the rest of the memory card standards, is based on hard disk drive technology.

microSD – TransFlash

TrashFlash, formerly known as T-Flash, was introduced by SanDisk Corporation in 2004 as the world’s smallest memory card, approximately the size of a fingernail. TransFlash (microSD) was specifically designed for being used in mobile phones. Motorola was the first mobile phone manufacturer to adapt the TransFlash memory card standard.

In the 3rd quarter of 2005 TransFlash was adapted by the SD Card Association as the third form factor memory card in the Secure Digital family, after SD Memory Card and miniSD. After the adoption, TransFlash changed name to microSD. The microSD has exactly the same dimensions and specifications as the TransFlash and therefore both memory cards are completely compatible to each other.

Today the microSD is the most common used memory card in mobile phones and the SD Card Association’s objective is to make microSD a de facto memory card standard for all mobile phones. All TransFlash and microSD cards always come with a SD Memory Card adaptor, which makes them compatible to all SD Memory Card slots. The microSD is about 10% in volume compared to SD Memory Card and about 30% compared to miniSD.

miniSD Card

The miniSD was introduced in 2003 by SanDisk Corporation in cooperation with Matsushita (Panasonic) and Toshiba. Later in that year the miniSD format was adapted by the SD Card Association as the second form factor memory card in the Secure Digital family. MiniSD is a smaller version of the SD memory Card format, about 60% smaller in volume, and offers the same benefits as the SD Memory Card expect of the writing protection switch.

MiniSD was designed specifically to be used in small portable electronic devices like digital cameras and mobile phones. But since all miniSD memory cards always come with a SD Memory Card adaptor, they are compatible to all SD Memory Card slots and thereby provide compatibility with the rapidly growing number of SD Memory Card compatible devices in the market.

MiniSD was the second, after SD Memory Card, memory card to be adapted by the SD Card Association, which today consists of three members. In 2005 the microSD was introduced as the third, and smallest, member of the Secure Digital family.

SD Memory Card

The SD Memory Card or Secure Digital was introduced in 2001 by SanDisk Corporation, Matsushita (Panasonic) and Toshiba. The SD Memory Card was based on the MultiMediaCard, MMC, memory card standard and has almost the same form factor, the size of a postage stamp, the only differences are that the SD memory card is slightly thicker and has a write protection switch. Since MMC cards are thinner than SD Memory Cards they can be used in all SD Memory Card slots but not vice versa.

The SD Memory Card is today the most common used memory card. It can be found in most digital cameras, PDAs and in many other electronic devices. The SD Memory Card slots can be used for more than flash memory cards. The SDIO, Secure Digital In & Out, is the general name for the many expansion modules that can be found in the SD Memory Card’s form factor. SDIO modules can be inserted in the slot and be used for other functions like Bluetooth adapters, GPS receivers, digital cameras, TV tuners, etc.

The SD Memory Card was the first memory card to be introduced in the Secure Digital family, which today consists of three members. In 2003 the miniSD format, 60 % smaller than the SD Memory Card, was introduced as the second member in the Secure Digital family. In 2005 the microSD was introduced as the third and the smallest member in the Secure Digital family. Since both miniSD and microSD come with an adaptor, they can be used in all SD Memory Card slots. Buy always the smaller format if you have electronic devices that support the SD Memory Card format and any other smaller format from the Secure Digital family.