Thinking back a few years, it's not hard to recall the surprised reactions of our parents and grandparents as we proudly extracted CompactFlash cards from early digital cameras. The surprised question, "that's where your pictures live?", sums things up nicely. But when its comes to the latest generation of small memory cards, a granny without glasses probably wouldn't be able to tell one apart from a postage stamp. That's small!
Even so, existing flash cards don't leave much room for complaint in terms of size or functionality. Currently, the most typical cards are the matchbook-sized CF (Compact Flash) cards, which can deliver up to 8 GB of storage, and the postage-stamp-sized SD (Secure Digital) cards, which come in capacities of up to 2 GB today, and should be available in a 4 GB size soon. Compact Flash is a preferred storage medium in digital cameras, but some cameras can also accommodate Hitachi's MicroDrive as well, which builds a 1" hard disk into a CF enclosure.
The MMC (Multimedia Card) was a predecessor to the SD card. These devices look much the same, but MMC includes neither write protection nor copyright protection, which probably explains its thinner profile. MMC cards still find a home in some devices these days, particularly in some of Nokia's mobile phones. Gaining ground in device memory, you'll also find Sony's proprietary Memory Sticks and the xD Picture Card as successors to the now-extinct SmartMedia format.
To accommodate removable memory cards in smaller devices, smaller form factors become necessary as well. That's why MMC and SD both come in reduced-size formats known as MMC Mobile (Reduced Size) and MiniSD, respectively. The MMC Mobile is only half the size of an SD card, while MiniSD's take up just 36% as much space.
As the next step toward shrinking formats still further, micro-formats for both standards should hit the marketplace, including MMCmicro and MicroSD. These are the very items we plan to investigate in this story.