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Introduction
USB stands for “Universal Serial Bus”; a specification developed by the so-called “USB Implementers Forum”, a consortium including Compaq, Intel and Microsoft, for a standard external serial interface to be used on computers and other digital devices. A USB flash drive is a small and portable mass storage device, which can be plugged into a USB port on a compatible digital device, and used to transfer data to and from that device. Despite its name, a USB flash drive does not contain any kind of drive per se; it actually contains a PCB or “Printed Circuit Board”, on which a flash memory chip or chips are mounted, and a microprocessor. Flash memory is solid state, non-volatile, memory that can be erased and reprogrammed in blocks instead of one byte at a time.
USB Flash Drive Features
The advent of the Internet in particular (bringing the possibility of downloading digital music, in MP3 and other formats, digital photographs, video clips, etc.) rendered the traditional floppy disk, with its miserly 1.44MB storage capacity, useless as a medium for storing and transferring data. Similarly, recordable CD and DVD media, while offering significant increases in storage capacity (700MB in the case of CD, and 8.5GB in the case of DVD, excluding Blu-ray and HD-DVD), compared to floppy disks, still lack the capacity and data transfer speeds of a typical USB flash drive. Recordable disks are also bulky, physically, prone to errors, and require specific drives and specific drivers to be installed on a computer to guarantee that they work correctly.
USB flash drives, on the other hand, typically offer storage capacities between 64MB and 16GB; as a rule of thumb, 1GB is broadly equivalent to 250 digital music files, or 1,000 high resolution digital photographs, and the latest specification “Revision 2”, offers high speed data transfer at up to 480Mbps (“Megabits per second”), roughly the same speed as “FireWire” or “IEEE 1394”. USB flash drives are compact and lightweight (sufficiently so to be carried around on a key ring, for example) durable, and compatible with almost any computer with a USB port. Saving data to a USB flash drive is therefore allows portability between home, office and campus or indeed, any publicly accessible computer, in a library, or cyber café, with the peace of mind of knowing that data is backed up, should a systems failure occur.
USB Flash Drive Tips & Techniques
USB flash drives are however, very easy to lose or indeed, to have stolen, so you do need to exercise caution with regard to the nature of the data that you store on them. Many USB flash drives have little, or nothing, in the way of security features and present a risk of sensitive or confidential data falling into the wrong hands, if the device is lost, stolen or “borrowed”. Of course, setting files or folders to “hidden” may be sufficient to keep them away from prying eyes in everyday situations, but generally speaking, proper security features are a much better idea. Password protection, and encryption, including the latest, corporate grade, AES (“Advanced Encryption Standard”) symmetric encryption, is increasingly becoming a feature of USB flash drives, and should be more than sufficient to protect your data from all but the most determined, professional thieves. Security measures do of course come at a premium, but the cost is minimal if compared to the extra security provided, and the cost of losing your data.
Speaking of losing data, you do also need to pay due care and attention to the type, and battery life, of any device (typically a PC, or laptop computer) to which a USB flash drive is connected, and how you remove the USB flash drive when you have finished working with it. If you are in the middle of writing data from, say a laptop, to a USB flash drive, and the laptop battery runs out completely, you run the risk of corrupting not only the file that is being written but also the FAT, or “File Allocation Table, of the USB flash drive, so that none of its files can be accessed. This problem can sometimes be repaired with recovery software, although not always entirely satisfactorily, so a better solution is to carry a spare battery, or to make sure that a source of mains power is available before starting any major data transfer operations.
Likewise, it is important to wait until all operations have finished before removing a USB flash drive from the USB port to which it is connected, to avoid data loss, or corruption. Many USB flash drives include an LED (“Light Emitting Diode”) which blinks rapidly when the drive is in use, but, as computers often cache data into memory, there may be a delay in actually writing the data to the USB flash drive. It is advisable to wait for a minute or two after the light has stopped flashing before disconnecting the USB flash drive. As a further precaution, you should also disconnect the USB flash drive as far as the operating system is concerned (using the “Safely Remove Hardware” icon on the Windows XP taskbar, for example).
Of course, USB flash drives are not just about storing and transferring data. Some applications lend themselves well to the creation of self-contained, portable versions, which take up very little storage space, and are therefore ideal for carrying on a USB flash drive. The Firefox web browser from Mozilla for example, is one such application, allowing you to take your list of “Favourites” and other browser preferences with you wherever you go. The Mozilla Thunderbird email client similarly allows an existing email address book (from Microsoft Outlook, or Outlook Express, for example) to be imported along with an existing mail folder structure, to produce a complete, portable, email system.
Furthermore, USB flash drives can also be “bootable”, and can therefore be used to contain operating systems (Windows Home Server, Windows Vista, etc.) subject to the BIOS (“Basic Input/Output System”) of the computer concerned which allows this facility. A Windows Home Server installation DVD, for example, requires 1.2GB of space, so a 2GB USB flash drive is sufficient, whereas Windows Vista requires 2.4GB, or 3.2GB, for the 32-bit, or 64-bit, versions respectively, so a 4GB stick is required. A single USB flash drive, with sufficient capacity, can be a boon for PC installation engineers, for example, allowing multiple bootable environments from a single source. Do bear in mind, however, that older USB flash drives may not, in fact, be bootable, and that older systems (that is, those manufactured before 2002) are unlikely to support booting from USB flash drives. Windows Vista also supports the facility to access a USB flash drive as additional memory, just like RAM (“Random Access Memory”). This feature is not included in Windows XP, but may be possible via 3rd party software applications, subject to the specification of the system concerned.
You should also be aware of the “autoplay” feature in Microsoft Windows, and its implications for the use of USB flash drives. Depending upon how a system is configured (that is, depending upon whether autoplay is enabled for USB flash drives, or not) it may be possible for any program to run from a USB flash drive, the moment that the drive is plugged in, without restriction. This is unlikely to present a problem if the USB flash drive is your own, and you are rigorous in your security measures, but you are using a USB flash drive that belongs to someone else, or that has been loaned to someone else, make sure that autoplay is disabled before you connect it. Otherwise, you run the risk of giving viruses, and other malware, carte blanche to wreak havoc with your system. Autoplay can be disabled completely, via the Group Policy feature in Windows XP for example, or again via 3rd party software tools.