Portable Data Storage of various shapes
The 50-year old tape is probably the oldest medium for data storage. It was relatively portable, too. It allows us to copy files from one computer to another in the absence of a network.
The tapes are still in use today, but mostly for backup purposes.
Then the floppy diskettes came around, followed by various other media including high-capacity disks, magneto optical disks, tape cartridges, writable and rewritable CD-ROMs-all with different storage capacities.
Another possible solution is to use an external hard disk. However, due to its sensitivity to shocks, external hard disks did not really become a popular means for temporary data storage. We did see an influx of removable cartridges from SyQuest, Iomega, Castlewood and others.
The most successful mini portable hard disk is probably IBM's one-inch MicroDrive, a tiny hard disk that could be inserted into a compact flash slot. MicroDrive comes in four storage capacities, the 170 MB, 340 MB, 512 MB and the 1 GB versions, and it is used in a growing number of digital cameras. A PC Card adapter enables us to read a MicroDrive in a notebook PC Card slot.
Then we have devices that use flash memory chips. Unlike the volatile memory chips inside our computer, the flash memory chip retains data that has been written on it without requiring power.
The advantage of flash memory is that, because there is no moving part, it can last virtually forever. Today, the compact flash memory cards come in a lot of forms, including CompactFlash (CF), Memory Stick, Secure Digital (SD) and MultiMediaCard.
Their popularity was boosted by the avalanche of gadgets such as digital cameras and PDAs. The flash memory devices are the best choice because of their resilience to shocks and low power consumption. Today, they are used to store almost any file, from Powerpoint presentations, MP3s, e-books, e-zines to video.
The CompactFlash format was introduced by SanDisk in 1994. SanDisk is the largest flash memory producer worldwide. Sony introduced its proprietary design that it called Memory Stick (www.memorystick.com). First used in Sony's own digital cameras and digital voice recorders, the Memory Stick has somehow gained a market share. MultiMediaCard was proposed by Siemens and SanDisk, and has also received support from leading technology makers (www.mmca.org).
There are other formats of the flash-memory devices. However, the addition of the Universal Serial Bus (USB) to the PCs and notebooks in the last few years have also made it possible for technology companies to design a slew of detachable storage devices. And the latest fad is the so-called keychain memory devices that can be inserted into one of these USB ports. They are called keychains because, well, they look and feel like keychains. They contain flash memory chips that can store up to 1 GB of data. USBDrive, for example, will soon be available in 2 GB capacity (www.usbmall.com). Prices for these devices range from US$30 to $600, depending on how much data they can store.
Like all other flash memory-based memory devices, the keychain memory device can transfer files at a very high speed capable of playing music or video directly. Another good thing about the keychain device is that it can be used in both Windows and Mac, so we can transfer files from one to the other without any problems. Because the USB has the plug 'n play capability, it is not necessary to have an extra software driver to enable Windows 2000, XP and Me machines to read the keychain memory device. Windows 98 users will still have to download a piece of free software to read these USB devices. Some of these keychain devices -- as well as the other flash memory -- based devices have built-in data protection. So, in the event you lose them, your data will always be protected.
These keychain memory devices are still pretty expensive, but they are definitely gaining popularity. They are also available from multiple sources. As usual, prices can be expected to go down as more and more people buy them.
-- Zatni Arbi