|
BOOT CAMP 069
INSTALLING A SECOND PARALLEL PORT
All PCs have a parallel port, and very useful it is too. On
the vast majority of computers this 25-pin socket is used by the printer,
however in recent years a growing number of other devices have appeared that
also require access to a PC's parallel port. These include scanners, high
capacity disc drives (Zip, Jaz etc.), video capture modules and PC-to-PC connections
like DCC -- the topic of last week's Boot Camp. Normally connecting one extra
device to the parallel port is not a problem, peripherals like scanners and
disc drives have 'through ports' that allow the printer to remain connected,
but if you want to add on any more parallel port devices, the single socket on
your PC simply cannot cope.
The computer industry has started to address the problem and
virtually all new PCs now have USB sockets, which can support more than 100
devices connected in a 'daisy chain'. However, it's a relatively new standard
and USB peripherals like printers and scanners are still a bit thin on the
ground and usually cost a little more than their parallel port cousins. The simple short-term solution to parallel
port overcrowding is to fit a second one. Most recent Windows PCs can support
up to four parallel ports, (designated LPT1 to LPT4), its not difficult, it
doesn't take long and it doesn't cost much, so let's do it!
Step 1 is to make sure your PC can be fitted with an
additional port (or ports), the first thing you'll need is a spare ISA
expansion slot on the computer's motherboard. Many recent PCs only have two or
three ISA slots to begin with so there's a chance you may not have an enpty one
if your machine has an internal modem, video and sound cards already fitted,
the only way to find out is to remove the lid. Make sure it is switched off at
the socket but you might want to leave the plug in, as this will ensure the
metal case remains earthed. Since we're going to be fiddling around inside the
machine it is a good idea to hold or touch the metal case every time you
venture inside as this will dissipate any static charges that may build up on
your body or clothes. The ISA slots are the longest ones on the board and usually
coloured black, with a notch or gap in the middle, if you see a vacant one
you're ready to proceed. Put the lid back on and make sure everything is still
working.
Step 2; obtain your parallel expansion card. They come in several
varieties with single, double or triple ports; single and double cards
generally cost less than £20 or so and can be obtained from most PC suppliers
and mail order specialists advertising in computer magazines. You can peruse
the instructions that come with the card but only for amusement, they're often
written in a Pidgin English that makes the average VCR manuals look a model of
clarity.
In order for the card to work it must be recognised by the
PC and given an identity so Step 3 is to check your machine's resources. Right-click
on My Computer, select Properties and the Device Manager tab. Make sure the computer
icon at the top of the tree is highlighted and double-click. This will open the
Computer Properties window, showing the interrupt requests (IRQs) used by the
components in your PC. The existing parallel port (LPT1) will normally be
assigned to 07, look for one or as many spare IRQs as your new card needs, on
most machines several IRQs between 09 and 15 are usually free.
Now for Step 4. Have a look at your parallel card, you will
see several rows of 'jumpers'. They small plug-in contacts, one row (or two or
three, depending on the type of card) will be marked IRQ, with numbers next to
the pins, move the jumper (or jumpers) to coincide with the free IRQs on your
PC. Switch off the PC, remove the lid again -- not forgetting to earth yourself
by touching the case -- and fit the card into the expansion slot. Replace the
lid and switch the PC back on. Follow the boot-up sequence on the screen and
watch for any error messages.
Step 5, most Windows 95/98 PCs will automatically detect the
new card and start the New Hardware Wizard, if not go to Start > Settings
> Control Panel > Add New Hardware and follow the instructions. When
asked allow Windows to search for the new hardware. Windows should find the new
card and automatically assign it the necessary identity (LPT 2 etc) and
resources. You can check that everything is okay by going back to Computer
Properties in Device Manager as outlined in Step Three.
If all has gone according to plan the new port(s) will be up
and running, ready to use, if not here's a few things to check. Change the
Parallel Port setting in the PC's BIOS to 'Auto' (refer to the manual for
instructions). If you get an error message saying there is a conflict in the
I/O range you will have to change the I/O jumper setting on the card, try one
at a time. If the card isn't recognised by Windows ensure that it has been properly
seated in the expansion socket, don't leave the card loose, use the retaining
screw to keep it in place.
Next week -- Newsgroups on the Internet
JARGON FILTER
DCC
Direct Cable Connection, a Windows 95/98 utility for
connecting two PCs together so they can exchange files
IRQ
Interrupt Request, a signal from a device connected to a PC motherboard
-- such as an expansion card -- asking the central processor to send receive or
process data
ISA
Industry Standard Architecture, type of expansion card
socket common to all IBM PC computers, used for sound and video adaptors, PC TV
tuners, etc.
USB
Universal Serial Bus, industry standard connection system
for peripherals (modems, joysticks printers etc) that does away with confusing
technicalities and allows 'hot swaps', allowing connection and disconnection
with the PC switched on.
TOP TIP
If you play a lot of games on your PC or you routinely use DOS
software it can be quite inconvenient to have to wait for Windows to load
before you can get into the DOS mode. There's a simple way of bypassing Windows
so that the PC boots straight to the DOS C: prompt. Open Windows Explorer and
click on the C: drive, in the right hand window scroll down until you find a
file called Msdos.sys, right click on it and select Properties, make sure the
'Read Only' attribute is unchecked and click OK. Double-click the Msdos.sys icon and if prompted open with Notepad.
Look for the line BootGUI=1, change it to read BootGUI=0 and save the file. The
next time you switch on the PC it will boot to the C: prompt, to start Windows
simply type 'win'.
|