Update: A Flash Memory Primer
By Leonard Fischer, Gannett News Service

(USA Today ) -- Oct. 4, 2001 -- A handful of readers have asked questions recently about flash memory, so today I'll provide a quick primer on the topic, as well as information on a new device for desktop PCs that makes it easy to exchange information between incompatible memory types.

So, what the heck is flash memory and why is it popular in handheld devices? Flash memory has a number of special characteristics. Let's take a look at each.

To begin, flash memory is non-volatile and has no moving parts. That means that it doesn't require electricity to maintain the information stored within it. I can best explain this by comparing the memory found in desktop PCs with flash memory.

Because your desktop PC's memory requires juice, it's wiped clean when you turn it off. When you power your desktop back on, you have to reload all of the programs and documents you were working on before you turned it off. But because handheld devices store programs and files in flash memory, the contents of the memory are maintained whether the handheld is on or off. Turn your handheld on, and it puts you back in the same program and file you were working on when you turned it off.

While flash memory is built into handheld PCs, it's also sold separately in the form of memory cards, which are compact and removable. You can think of these cards as miniature floppy disks or hard drives that can be used to store additional programs and data, as well as share them. These cards come in a variety of formats and memory sizes. Let's take a look at each.

CompactFlash: This is probably the most popular type of removable storage. These square cards, which store up to 512 megabytes of information, are popular in Pocket PC devices. They're also work in the Palm-compatible handhelds from Handera, as well is Handspring Visors that have a special Springboard module. CompactFlash also works with laptop computers by popping the memory modules into a PC Card adapter that costs about $10. What's more, CompactFlash is a popular storage medium for digital cameras and MP3 players.

SmartMedia: These memory cards, which are much more popular for use in digital cameras and MP3 players, are about the thickness of a credit card. They store a maximum of 256 megabytes of information.

Memory Stick: This is a flash memory standard developed by Sony and used in Sony's Clie line of Palm-compatible handhelds. Memory Sticks are roughly the same size and shape as a piece of chewing gum. While Clies are the only handhelds that work with Memory Sticks, Sony builds this type of flash memory into other high-tech devices it makes, including digital cameras, digital camcorders and even some of its laptop computers. Sony also licenses the technology to other companies, which use it in their devices. Memory Sticks can hold up to 256 megabytes of data, but larger sizes will be available soon.

Secure Digital and Multimedia cards: These tiny cards, which are barely the size of postage stamp, are finding new popularity in handhelds. Palm recently began including Secure Digital and Multimedia card capabilities in its m500, m505 and m125 handhelds, and Compaq has promised it in new iPAQs that run the Pocket PC 2002 operating system. Secure Digital and Multimedia cards also have found popularity in the latest digital cameras and digital music players. At present, Secure Digital and Multimedia cards max out at 64 megabytes of storage, but larger capacities are on their way.

IBM Microdrive: While not actually flash memory because they have moving parts, Microdrives are tiny hard drives with capacities of up 1 gigabyte. They share the same form factor as CompactFlash memory and work in most devices that can accept what are known as CompactFlash Type 2 memory cards.

The problem some readers face is how to share information between incompatible forms of flash memory. For example, you might own a Sony digital camera that uses Memory Sticks and a Pocket PC that accepts CompactFlash. You want to take photos you've stored on the Memory Stick and transfer them to your Pocket PC's CompactFlash card so you can show them off wherever you are.

You can do this by connecting both devices to your desktop PC. First, copy your images from the camera's Memory Stick to a folder on your desktop PC. Next, copy the images onto your Pocket PC's synchronization folder. Then synchronize your handheld device with the desktop PC so the images are stored on your handheld. Finally, you can copy them to the CompactFlash card for permanent backup.

This process is somewhat cumbersome, requiring several minutes and a number of steps. Luckily, there's an easier way thanks to a new device called the Pocket DigiDrive from Addonics Technologies.

The Pocket DigiDrive is a small box you attach to your desktop PC -- either Windows or Macintosh -- through the Universal Serial Bus (USB) port. On the front of the DigiDrive are slots that accept all of the types of removable flash memory described above. To transfer photos from a digital camera's Memory Stick to a handheld's CompactFlash card, you just plug both cards into the front of the box. They appear on your desktop computer's screen as icons like those that represent hard or floppy disks. Now, all you have to do is drag the icons that represent your photos from one type of memory card to another, and, voila, you are finished. Pop the CompactFlash card back into your handheld and your photos are ready to go.

The Pocket DigiDrive costs $89. That's somewhat more expensive than other desktop flash reader/writer devices, but the extra cost translates to maximum flexibility because the DigiDrive is the first device that works with all of the popular flash formats. You can learn more about it www.addonics.com.

Friday: Lots of readers have expressed interest in the Digital Angel system that can track the location of a person in distress. I'll have the most up-to-date information from the company behind the technology.

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