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Flash! Is the Zip Disk dead? How do you move significant amounts of data from one place to another? For years, the ubiquitous Zip disk reigned supreme. Could USB Flash Disks be to the Zip as the Ice Age was to dinosaurs? Put it on the BUS! M oving large amounts of data – photos, music, video, etc, from one computer to another has been a problem since there have been computers and large amounts of data! If the files were more than a floppy’s worth (ie, 1.4MB or thereabouts), smarter solutions needed to be found. Indeed, very close to home, this problem has caused not just a few headaches here at SILICON CHIP. As you would imagine, magazines like SILICON CHIP have been produced on computers now for many years (thank heavens for desktop publishing, photo manipulation and drawing packages!). But we don’t own a huge printing press capable of printing a 100-page, four-colour magazine (office photocopiers don’t quite cut it!) So if the mountain won’t come to Mohammed, Mohammed has to go to the mountain. Ergo, each month we have to send a complete magazine’s worth of files to the printers. Very early on, we used whopping (for then!) 44MB “Syquest” disks – many of them for each issue. Even progressing to 88MB Syquests helped only a little. They were somewhat unreliable and, being magnetic recordings, occasionally suffered catastrophic failure. There were even 16  Silicon Chip a couple of times when we were forced to record the magazine on a hard disk, remove the hard disk from the computer, package it very carefully and then airfreight that to the printers. (Don’t knock it – it worked. And got us out of some tight spots!) We also used ZIP disks – both in their original 100MB format and their 250MB reincarnation. The disks themselves were usually very reliable in the short term but we found the drives left a little to be desired mechanically. We By Ross Tester had several failures in the one year. Besides, ZIP disks were/are relatively expensive. SILICON CHIP was a very early adopter of CD-ROMs (back when CD writers operated at x1 or x2 maximum and discs were several dollars each!). To this day, we still record the bulk of the magazine (usually about 500-600MB per issue) on a CD-ROM and despatch it to the printer. At least these days we have 40x and 50x writers. It is very difficult to buy a computer Physically small enough to carry around on your keyring, capacity-wise large enough (if you pay enough!) to take your sensitive data with you. This one is a 32MB drive but you can now get them up to 2GB. www.siliconchip.com.au They’ve been faithful servants, but maybe it’s time they were retired. . . without some form of CD writer (or rewriter, or DVD writer, etc) installed – so just about everyone has one. So what’s wrong with the average person using CD-ROMs to transport data between computers? Nothing, much. Except that copying files to a CD or DVD is certainly not as simple as copying files to, say, a hard disk (or even a ZIP). It is not an instant process and CD writers are definitely not fault (or interruption) tolerant in the recording process. And if you are in a screaming hurry (eg, the courier is tapping his fingers loudly on the reception desk), Murphy’s law says that’s when you are going to write a “coaster”. Besides, what if you only need a relatively small amount of data – say a few dozen megs or so. Writing to a 660MB CD seems to be something of a waste to us, even taking the low cost of CDs these days into account. We’re not trying to dismiss CDs out of hand – as we said, we use them regularly. But for the casual transporting of data between machines, there is a better way! ports which have been on computers virtually since day one is in the way data is transmitted. Serial and parallel ports send data bit by bit. The USB organises the data into “packets” and sends those. Because of this, a USB port requires only four wires – two for power and two for data. (See the separate box which explains more about the USB port). It took some time for the USB to catch on. Indeed, in the early days there was so little call for USB devices (or more likely so few USB devices available) that for some time case manufacturers kept USB ports on the back panel of the computer – about the most inaccessible place they could be. But over the past couple of years, we have seen a plethora of USB devices released – so much so that just about every computer sold these days has the USB ports on the front panel and many motherboards support four USB ports. If not, inexpensive add-on cards can give you more USB ports for your computer. While you can buy just about any peripheral these days to operate via a USB port, the thing that most interests us here is the range of USB storage devices now available. Most particularly, we are looking at some of the “flash disks”. These are available in many formats – we’re going to look at a few of these in more detail shortly – but apart from their healthy storage capacities, the most noticeable thing about flash disks are their size (or lack thereof!) Most are only a couple centimetres wide and perhaps five or so long. If you have to carry data around with you, or move it from PC to PC, this surely must be the simplest and easiest way yet. What’s more, on most modern machines, when you plug one of these USB devices in, the computer not only recognises it immediately but assigns a drive letter to it, making it “just another hard drive” on your computer. Anything you can do with a traditional hard disk drive, you can do with a USB flash disk drive. Flash “Disk Drive”? No, they’re not – disks nor drives! The term has stuck because everyone is used to, well, disk drives, where things (disks) spin inside and make whirring noises! The name can be a bit confusing – a flash disk is entirely solid state; there is no mechanical “disk” to “drive”. In fact, a flash disk is a type of EEPROM, (electronically erasable programmable read-only memory). The “ROM” part can be anything from 16MB right up to 1GB and now beyond. (2GB are available but they’re expensive). That’s a rather impressive amount of storage for something that can not only be hidden in the palm of your hand (or even between your fingers!), it can often be hidden inside other devices such as watches, pens, etc. We’ll look at some of these shortly. Unlike other forms of memory, the flash disk does not need constant power, just while being read from or written to. Once data is written into it, it stays there until it is erased and Enter the USB . . . There probably wouldn’t be a computer sold today that doesn’t include at least two (and sometimes more) Universal Serial Bus, or USB, ports. USB offers high speed and reliable data communication (especially in its newest incarnation, USB2.0). The USB standard was developed by a consortium of organisations including Compaq, Hewlett-Packard, Intel, Lucent, Microsoft, NEC and Phillips. The main difference between the USB port and the serial or parallel www.siliconchip.com.au Flash disk manufacturers are getting pretty clever – this is the new “Cruzer Micro” from SanDisk. It’s very fast (USB2), is available up to 512MB capacity and even has an optional portable docking station which turns it into an MP3 player! SanDisk also has a Titanium model in the Cruzer range, claimed to be virtually indestructible. March 2004  17 re-written. Again, this lends itself very much to a portable format. USB flash disks are, by and large, “hot swappable” – another big advantage over many other forms of storage. You don’t have to power down the machine, swap the drive, and power back up again. It can be inserted and removed at will, with just a couple of provisos: (a) Do we have to say it? You must never remove flash disks (or any form of storage) while being read from or written to (most types of flash disks have a LED on them to warn you when “in use”, a la the hard disk LED on your PC). Not only would data be lost, the chances are very high that other data already on the flash memory would be scrambled. (b) While you can simply remove the device from the USB port once writing is finished, most operating systems don’t particularly like this and give you a stern warning when you do it (you almost expect a hand to come out of the monitor and slap you on the wrist). The operating systems like to be told that you’re about to remove the USB device and give you an icon on the task bar to allow you to do this easily. They then graciously give you permission! With the exception of Windows 98/SE, you normally don’t need any drivers. You simply plug ’em in and This is a REAL USB Pen Drive – complete with the pen! The flash disk is in the top half of the pen and is unscrewed from the body to reveal the USB connector (see inset). your computer will tell you that it has found the disk and is ready to rock and roll. It will simply assign the next available drive letter in your system unless you specify otherwise (which you can easily do). Why would you do that? I have made my USB flash disk drive “U” (U for USB) in all computers I use it in, because some software I use insists on a certain drive/directory/file setup and gets confused otherwise. Nobody really knows (yet) how long that data will stay in memory without power. Various sources claim between ten and forty years (yes, years) – but we’re going to have to wait for quite a while to verify those claims. By the way, USB Flash Disks, in all their varieties, are not the only place you’ll find flash memory used. It’s everywhere these days – from the memory card inside a digital camera (and they are also available in many varieties!) to video games consoles, to the PC-card memory used in notebooks and laptops . . . even your computer’s BIOS chip is likely to be flash memory (definitely an EEPROM at any rate). USB Flash Drives Reproduced significantly larger than life size, this photo shows what’s inside a typical USB flash disk drive. As you can see, there’s precious little in the way of a disk . . . 18  Silicon Chip These are commonly available and are now getting quite cheap. Sometimes they are called keyring memory because they are small enough to go on a keyring. Other suppliers call them pen memory (though that could be confusing, as we will see in a moment). Our sample 128MB drive came from Oatley Electronics in Sydney (www.oatleye.com; 02 9584 3563) who have drives from 16MB to 512MB. Most of them are 78mm long, 22mm wide and 11.8mm deep (the largest drive is 82mm long). There is a write-protect switch to prevent you accidentally destroying data. Prices from various suppliers vary enormously – we found Oatley’s compared well. The 16MB sell for $24.00, while the 512MB sell for $340.00. Obviously, the larger capacity drives are the best value at about 66c per megabyte. www.siliconchip.com.au Look, it’s a watch. No, it’s much more than that: it’s also a 128MB flash disk drive. This one is from Dick Smith Electronics and sells for $99.86. The package includes a driver CD and USB extension cable. This drive has the incredible advantage (for me) of going wherever I go – no more lost data or lost disks! And here is the interface: a standard USB cable (albeit pretty short!) which normally hides in the watchband. By the way, this watch is definitely NOT waterproof . . . They’re supplied with a USB extension cable and a mini CD containing Win98SE drivers and other goodies. A neck lanyard is also supplied so you can actually wear the disk! The latest models from Oatley have a couple of new really worthwhile features: an advanced email server; Zip compression and decompression to pack more onto your drive; a PC lock (you can use the flash drive to lock your PC – just be careful not to lose the drive!); and data encryption so if you do lose the drive, no-one else will be able to read it. One of the biggest advantages of these drives, the tiny size, is sometimes a disadvantage to me: I’m forever losing it in the bottom of my briefcase! Similar flash drives are also heavily flogged on Ebay so if you’re an Ebay user and prepared to take some risk, you might save a little bit. And at least one US webstore was selling a 128MB flash drive for $US19.99 (about $AU26) around Christmas time! Since starting the research for this feature, one problem with flash drives has emerged. We said they are tiny but perhaps, not tiny enough for some computers. Flash drives have the USB connector moulded into the end of the case, usually with some form of collar around the end. We have come across several notebook computers where the USB port is recessed slightly into the case and the collar prevents the connector making reliable contact (sometimes not at all). Again available in capacities from 16MB to 512MB, these came from an Ebay shop: Chansnetwork. Once again, prices vary depending on size – they range from $27.00 for 16MB through to $280.00 for the 512MB version. Again, the larger the capacity, the better value – the 16MB costs $1.68 per megabyte; the 512MB costs 54c per megabyte. You can access chansnetwork via Ebay (search USB pen) or give them a call toll free on 1800 002 810, ext 8633. www.siliconchip.com.au In this case, the simplest answer is to use the USB extension cable that is supplied with many flash drives (or is available from computer stores very cheaply). Pen drives Remember we said before that calling flash drives “pen drives” could be confusing? Here’s why: we found a flash drive actually built into a pen! The top part of the pen unscrews to reveal a USB plug – the drive’s indicator LED is built into the pen case top. These pen drives operate exactly the same as a “normal” flash drive. And, surprise surprise, just like a normal pen (OK, so maybe just a tad heavier than your Bic Biro!). They come in a gift box with a mini CD driver disk. USB watch drive ­If you thought the pen drive was nifty, have a look at this one from Dick Smith Electronics. It’s a USB flash drive built into a fully functional, fashionable man’s watch. It looks just like a digital camera – and it is, until you want it to become an emergency flash disk drive! March 2004  19 should be able to read and write to the camera card – and it could! I copied the files I needed to the camera, unplugged it and transported it. I plugged it in the other end: presto, another hard drive. I am not saying every digital camera will work like this. But I would assume the vast majority would – if they operate via the USB port and have a drive letter assigned, you should have no problem. It’s a USB drive but it’s not a flash drive. This box contains a standard 80GB IDE hard drive (see inset above) along with the IDE to USB interface. You can buy cases without drives as well. Not shown here is the 12V power supply required by this box. There was (at time of writing) only one capacity available, 128MB, and this sold for $99.86. That compares very favourably with either the flash drives or the pen drive above AND you get a great-looking watch thrown in. For reasons best known to themselves, DSE call it the Dataspy (Cat XH8138). You also get a full-size CD with a user’s guide (PDF), drivers for Win98/98SE and OpenOffice.org plus ZoneAlarm software. There’s also a quite comprehensive printed user manual. I mentioned before that I am forever misplacing the flash drive because of its tiny size. Same thing will happen, I’m sure, with the pen drive. (Where did I leave my pen?). It simply won’t happen with the watch drive because it’s there, on my wrist, when ever I need it. The connection to the USB port is made via a small (50mm) lead which normally sits in the watch band. Like the flash drive, an extension cord is provided for the USB port so you don’t even have to remove the watch to read the disk (just remember to disconnect yourself before you walk away!). I’m not exaggerating when I say that everyone who has seen the DSE Dataspy is impressed – the usual comment is “I’ve gotta have one of those!”. You can get yours at any Dick Smith Electronics/DSE PowerHouse store, or mail/net order (1300 366 644 or www. dse.com.au). Thinking outside the box . . . A few weeks before starting this 20  Silicon Chip Thinking inside a box! feature (before I acquired these goodies!) I needed to move, in a hurry, some large (50MB) graphics files between two computers several kilometres apart. Trouble was, I didn’t have any means to do it. And as luck would have it, my CD burner was in yet another machine. I figured I had two choices. Move the CD burner (naaaaah!) or “ftp” the data over the ’net – but I really didn’t want to wait the eight hours or so it would have taken on my (painfully slow) dialup connection. What to do? It suddenly dawned on me that I was looking straight down the barrel (or should that be lens?) of the answer: my digital camera! It too has a flash disk inside it – in this case, a 64MB SmartMedia card. And it has a USB connection cable. When plugged in and turned on, the camera behaves just as any hard disk drive, just like the flash memory. I reasoned that being the case, I OK, so we have extolled the virtues of USB flash drives. But what happens if you want REAL storage capacity – more than the one or two gigs currently available. Of course, there is an answer. It’s not a flash drive – though it behaves pretty much the same (you plug it in to the USB port and away you go). It’s a bog-standard 3.5-in IDE hard disk drive (in this case an 80GB Seagate), mounted inside a case which also contains an IDE-to-USB converter. Because “normal” IDE drives also require 12V, there is an also an external plugpack mains supply. We found this solution at one of our usual computer suppliers, Cam1 (www.cam1.com.au; 02 9999 5600), although these are also very commonly available at computer stores and through Ebay. With the drive, it cost us $350.00 We’ve also seen these cases sold without drives (significantly cheaper), so you can put your own one in (or change it as required). Incidentally, you can buy similar cases for 2.5-inch “notebook” drives (these don’t need an external supply because they need only 5V and this is available from the USB port). These “Dazzle” USB card readers from Oatley Electronics accept a variety of flash memory cards and can also be used for data storage – if you happen to have the right card! The readers themselves are very cheap. www.siliconchip.com.au These are also much cheaper – you shouldn’t pay much more than about $30.00 -$50.00. Card readers Before we finish with USB devices, it’s worth noting how cheap USB card readers have become lately. Oatley Electronics have them for $6.90 each, with models handling secured digital/ multimedia, CompactFlash, or SmartMedia cards. (If you buy all three, you can get them for $15.00). Jaycar Electronics (www.jaycar. com.au; 1800 022 888) have a 6-in-1 internal USB card reader for $54.95. These cards are all examples of flash memory in use. You can write to or read from these cards just as you would a normal USB flash disk. We found the reader particularly handy because we’d recently purchased a second SmartMedia card for the digital camera. So when not needed for the camera, the card became yet another hard disk. Depending on the computer and operating system, it could be as simple as plugging the reader in. If drivers are needed, they can be downloaded from the Oatley website. Removable drives (non-USB) These have been around since Adam played half-back for the under-7s, so it’s unlikely you haven’t at least seen them advertised, if not used them yourself. We looked at them in detail way back in the October 1997 issue. First, what they are not: unlike all of www.siliconchip.com.au This is a standard IDE drive in a removable drawer (often sold as a “Mobile Rack”) and for some time has been a popular method of making data portable. However, we have had a few instances of data loss or damage, possibly due to poor contacts between the drawer and the frame. the other storage media we’ve looked at in this feature, they are not a USB drive. What they are is a standard IDE hard drive used on the IDE bus, just like your normal (internal) IDE hard disk drive. A plug-in drawer contains the hard disk drive, while a matching caddie is located inside the computer, with the drawer pushing into place via a flap. The caddie has a multi-pin socket and the drawer a matching plug; when pushed home the two mate and provide all the connections (data and power) required by the drive. They’re quite cheap and readily available at most computer stores or Ebay. The drawback (pardon the pun!) is that you need to buy more than one caddie if you are going to use them on more than one machine. Of course, if you buy two sets you can also use a second hard disk. One point to note about these drives if you use an older (slower) drive: if you fit the drawer drive as the slave drive on your primary IDE port (ie, the port which also has your master drive), the master drive will be crippled back to the speed of the older drive. It’s always best to fit the draw drive as the slave on the secondary IDE port, the one which has your CD-ROM or CDR on it as master. Finally, these drives are exactly the same as any other IDE drive – you must power down before removing the drawer – unless you buy one specifically intended for “hot swapping”. These are not uncommon but are more expensive. We must be honest here: over the years we have had problems with this drawer system. Perhaps it’s oxidation of the contacts; we’re not sure. But there have been intermittents and loss of data, even a dead drive – to the extent where now we do not trust them (nor use them!). Not when USB flash disks are available! March 2004  21 About the Universal Serial Bus . . . As you may know, there have been two versions of USB – USB1 (or more correctly 1.0 then 1.1) and USB2. The difference is mainly speed: USB1.1 allowed a data throughput of between 1.5 and 12MB/s, the newer version 1.5, 12 and a whopping 480MB/s. While 12MB/s is quite respectable, the differences are quite staggering. Looking at manufacturer’s data sheets, a typical flash drive could back up 1MB of data in 17min 33sec via USB1.1. Via USB2 this would be thirty times faster at just 37sec. Transferring 50 hi-res (25MB) digital photos or MP3s wouldn’t be quite so dramatic: 32 seconds vs 7 seconds, or about five times faster. USB 1.1 and USB2 are usually (with some exceptions) interchangeable because USB2 encompasses low and medium speeds as well. Most plug-in USB flash drives conform to the USB1.1 standard. The USB port has four contacts. Pin 1 is typically colour coded red (+5V), pin 4 brown (power ground) and pins 2 and 3 connect to a twisted pair (yellow and blue) to carry the data. The cable is also shielded. The USB cable is generally limited to five metres and up to 500mA can be supplied from the port for devices which need power, although many USB peripherals have their own power supply. Needless to say, USB flash disks do NOT fit into this category. Upstream and downstream Most flash disks plug directly into the host computer via the plug moulded in. Other devices which need to connect via a USB lead usually have different plugs on each end. (Above): upstream (or type “A”) USB plug connects to the PC. (Below): downstream (type “B”) connects to the USB device. The USB plugs are designed to work a certain way around. The “upstream” connector (also called a type “A” connector) is designed to plug into to the host computer. Conversely, the “downstream (or type “B”) connector plugs into the USB device. Most type “B” plugs are smaller and squarer than the flat, rectangular type “A”. Note that there are at least three (and probably more) sizes of type “B” plugs, depending on the manufacturer of the USB device. There are also USB “extension leads” which have a type “A” connector on one end and a socket the same as the host PC on the other end. Using hubs Up to 127 USB devices can connect to the host device, either directly or (if you run out of ports) via a USB hub. Two and four-port USB hubs are very common (and cheap!), while larger numbers of ports are not hard to get. Hubs can be either self-powered (via a supply) or themselves powered by the USB bus. If you need to add power-hungry USB peripherals (or a lot of them!) you’ll need self-powered USB hubs to ensure enough power is available. Also, if you wish to exceed the 5m limit, you can do it by daisy-chaining hubs. How does it know? When the host computer powers up, it queries (or “polls”) all of the devices connected to the bus and assigns each one its own address. This also occurs when a new device is plugged in. If the device is a flash drive (or even contains a flash drive, such as a digital camera), the host computer then assigns the “drive” the next available drive letter. From then on, it behaves just like any other disk drive until it is removed. Each device is queried as to what type of data transfer it wishes to use. There are three types: Interrupt - A device which sends little Pin Name Description 1 VBUS +5V DC 2 D- Data – 3 D+ Data + 4 GND Ground USB Port pin assignments. 22  Silicon Chip A close-up view of the USB port as would be fitted to your PC. data, such as a mouse or keyboard, would use the interrupt mode. Bulk – Where data is received in one big packet (for example in a printer), the bulk transfer mode is used. A block of data is sent to the printer (in 64-byte chunks) and verified to make sure it is correct. Isochronous – A streaming device (such as speakers) uses the isochronous mode. Data streams between the device and the host in real-time, and there is no error correction. The host keeps track of the total bandwidth that all of the isochronous and interrupt devices are requesting. They can consume up to 90% of the 480Mbps of bandwidth that is available. After 90% is used up, the host denies access to any other isochronous or interrupt devices. Control packets and packets for bulk transfers use any bandwidth left over (at least 10%). The Bus divides the available bandwidth into frames with the host controlling them. Frames contain 1,500 bytes with a new frame every millisecond. During a frame, isochronous and interrupt devices get a slot so they are guaranteed the bandwidth they need. Bulk and control transfers use whatever space is left. System compatability On the PC, USB works with most recent operating systems from Windows 98 on. It also works on the Mac. Drivers will probably need to be loaded for Windows 98/SE but more recent operating systems (eg, Me, 2000 and XP) have the drivers built in. However, if you run Windows 95 or Windows NT on your computer, you’re out of luck. Neither recognise the USB – Win95 because it is simply too old; WinNT because it was never designed to work with USB. SC www.siliconchip.com.au