|
BOOT CAMP 092
THE UNIVERSAL SERIAL BUS
If your PC was made after 1997 there is a good chance it has
Universal Serial Bus (USB) capability, you may even have spotted the sockets on
the back panel. There are usually two of them; they're quite small, rectangular
in shape and just over 1cm wide.
USB is a determined attempt by the PC and peripherals industry
to clear up the confusion and data bottlenecks created by the standard PCs serial
and parallel ports. A couple of serial sockets and a parallel printer
connection were all that was needed in the early days but now, with dozens of devices
clamouring to get a high-speed data connection to your PC those clunky old
ports can no longer cope.
The principle advantage of USB is that in theory up to 127
devices can be connected to a computer, by 'daisy-chaining' the cables or using
a series of 'hubs', which are a bit like multi-way mains socket adaptors. In
practice it's unlikely that such a large number of peripherals would ever be
linked to a single PC but you get the idea. Another key benefit of USB is that
devices can be 'hot swapped', in other words plugged and unplugged without
having to re-boot or reconfigure the PC.
As far as transfer data speed is concerned USB is moderately
fast at 12Mbits/second (1.5 megabytes/sec). That compares with the relatively sedate
standard serial and parallel ports which trundles along at around 115kbits/sec
(0.15Mbytes/sec), but it is a good deal slower than the fast-emerging FireWire
or (IEEE-1394) standard which is capable of speeds up to 400Mbits/s (50Mbytes/sec).
FireWire is intended for demanding applications like digital video whereas USB
is ideal for more down to earth jobs, like connecting PCs to printers and
scanners, mice, joysticks, loudspeakers, digital cameras, modems, tape and disc
drives. USB connectivity is improving all the time and in addition to sockets on
the backsides of PCs a number of monitors are now fitted with USB hubs (or
sockets for hub modules). USB sockets are also starting to appear on laptops
and portables, which means they can more easily share office peripherals
without recourse to clumsy port replicators and adaptors.
It all sounds wonderful, so what's the catch? There are several,
starting with patchy USB support on PC motherboards and operating systems made
before 1999. From now on virtually all new PCs should be fully compliant but there
are a lot of machines with BIOS programs and USB sockets that don't work, and
others with USB capability, but no connecting sockets. Windows NT 3.5 and 4.0
do not support USB, Windows 95 has limited USB capabilities but it is
notoriously unreliable. Windows 98 is much better and Windows 2000 will be full
compliant though Win 98 is not completely trouble free. Until recently the
number of USB peripherals was quite limited and manufacturers usually charged a
premium for the facility but that is changing fairly quickly as new products
come on to the market.
USB has a few other limitations; it is not really suitable
for direct PC to PC connections or networking. Devices called USB 'Bridges' or
USB to USB adaptors are available but they are not as efficient or cost effective
as traditional local area network LAN solutions like Ethernet. Do not be
tempted to connect two PCs together by USB cable, it can fry chips on the
motherboard! The length of USB cables is limited to around 4 metres; it is
possible to extend cables in multiples of 4 metres using 'powered hubs' but it
starts to get a bit complicated. Reliability is another concern, there have
been reports of PCs failing to recognise peripherals, they may have to be switched
on and off or plugged and unplugged several times before they work. USB
installations have been blamed for causing Windows Registry problems, failures have
occurred when bus systems are put under pressure and some users have
experienced difficulties configuring USB to Ethernet connections.
Nevertheless, for most straightforward home and office applications,
such as connecting printers, scanners and digital imaging devices, USB can solve
a lot of problems and make life easier, if you are starting from scratch, or
thinking of buying any new peripherals. So how do you find out if your PC is up
to the job? Providing your PC fulfils the basic criteria, namely it is a fairly
recent Pentium model made after 1997, has the necessary sockets on the back
panel and you are using Windows 98, the next step is to download a PC
evaluation utility from Intel called USB System Check. It checks your PCs
hardware and software and reports back on any faults or problems. USB System
Check is quite small (around 540kbs) and can be obtained from: http://www.usb.org/data/usbready.exe
Start by creating a new folder in Windows Explorer – call it
USB or something similar – and when asked by your Internet browser, save the 'usbready.exe'
file in your new folder. Click on the USBReady icon and the report window
appears after a couple of seconds, along with suggestions for any necessary
hardware or software upgrades. Next, check your PC's BIOS or set-up program,
this can normally be accessed during the boot up routine by pressing Delete (other
key or key combinations are usually displayed on the screen). The USB options
are usually contained in one of the sub menus (PNP and PCI Setup, Peripheral
Configuration, Advanced Setup or PCI Control), make sure the option is enabled.
Installing USB hardware is (or should be) simple and is
similar to the procedure used to connect serial and parallel port devices. USB
peripherals normally come with a driver installation disc, which you load into
the machine, when requested by Windows, or when using the Add New Hardware
utility in Control panel. The whole process should be more or less automatic and
once completed you can plug and unplug the device without any further actions
on your part.
Next week – Email
away from home
JARGON FILTER
DAISY-CHAIN
USB devices have two sockets so they can be connected
together, one to the other, like a chain
HOT SWAP
The facility to be able to plug or unplug a peripheral
whilst the PC is running
HUB
A multi-way connector with one input and several outputs
TOP TIP
You can do all sorts of things with the items on the Windows
98 Start menu, they can be copied, moved around and have their properties
changed but the one thing you can't do is rename them, unless you have Internet
Explorer 5.0 on your system. However, there is a way around that. You can
change the name of an icon by left clicking on it and dragging it onto the
desktop, it can then be renamed by clicking into the name field. Next, right-click
on the newly named icon, drag it on to the Start button, put the mouse pointer
where you want it to go on the Start menu, release the mouse button and choose
'Move Here' from the dialogue box that appears.
|