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A heart
transplant
for an aging
computer
Should you buy a new computer or
upgrade an existing one? Often it depends
on how much money you have and
whether or not you’re prepared to delve
into your machine.
By ROSS TESTER
I
WANTED – no needed – a new
computer. Since purchasing my
last computer just on two years
ago, software had become so complex,
so demanding that my current machine simply wasn’t up to it any more.
I guess I’m luckier than the average computer owner. All told I have
three computers at home, not because
I’m greedy but more because until a
couple of years ago I kept expanding
the system as a new model came out.
So I have managed to assemble a
system which would do a small office
reasonably proud. Then again, that’s
exactly what my home system is for
– a small office.
4 Silicon Chip
And while I also have a reasonable
amount of hard disc storage (well,
with two or more drives in each machine you’d expect that), the one thing
I don’t have is performance. I have one
computer with a fairly slow 100MHz
586 processor but the majority of my
work was still being done on an old
faithful 486 machine.
Until fairly recently that didn’t
matter too much because most of the
crunching power I needed was done
elsewhere. However, I had to prepare
a colour brochure recently and sitting
watching that infernal hourglass on
the screen convinced me that the
time had come! After all, Mr Gates’
hourglass was costing me money! But
which way to go?
The basis specs
I had already decided on the type
of computer I wanted. The basic specs
were:
(1) a proven motherboard with the
fastest processor I could afford;
(2) the best graphics card I could
afford;
(3) the most memory I could afford
(absolute minimum 32Mb);
(4) a very fast CD-ROM drive and a
large hard disc (or two or three).
With the price of computers almost
in free fall over the past year or so,
ABOVE: the new ASUS motherboard
in “bare bones” form. At top left are
the four sockets for 72 pin DRAM,
below that the expansion slots – white
PCI and black ISA. The large white
socket at bottom right is the “ZIF”
socket for the CPU. The board will
take anything from a 33MHz 486 to a
200MHz Pentium (or equivalent).
was it really a proposition to do what
I’ve done every time before – upgrade
the existing computer? Or would it
be better to simply lash out and buy
a brand new all-singing, all-dancing
computer. After all, the sort of machine I wanted was being regularly
advertised for about $2500 or less.
“Oh no,” she said (she being the she
who must be obeyed). “Not another
computer. You already have three and
you can only use one at a time.”
Having seen all the advertisements
for what amount to some very good
machines, I’m still not sure she
was right. But I was able to make a
convincing argument for upgrading
one of the existing machines. Ours
is no different from many mum &
dad businesses, “mum” is not only
the one who must be obeyed . . . she
The Matrox Millenium II graphics
card that was purchased has 4Mb
of memory (WRAM) on board, with
provision to expand this to 16Mb.
also keeps a pretty tight reign on the
cheque book!
Looking at it logically (how else do
you look at a computer), I already had
most of what I needed. First, the old
486 had a perfectly good tower case,
complete with power supply, a flop-
py drive and three hard disc drives
with over 6Gb capacity. It also had
a magneto-optical drive and not one
CD-ROM drive but five (one is a highspeed drive, while the other four are
integrated into a CD-ROM jukebox).
As for the internal cards, there was
December 1997 5
cause the I/O is now usually built in.
Finally, there was the monitor, keyboard and mouse, all of which were
fine. Buying a new computer would
therefore duplicate much of what
I had and leave me with the job of
transferring some of the components
out of my existing system to the new
machine. It didn’t make a lot of sense.
So I went down the upgrade path.
In the end, I saved a few dollars and I
got exactly the configuration I wanted
– after all, I chose it! I’m also very sure
about the quality of the computer –
something that can be a problem with
some bargain-priced systems. After
all, if they are that cheap, something
must suffer.
The motherboard
The difference between ISA and PCI cards is clearly visible in this photo. The
top card is an Adaptec SCSI controller (ISA) while the lower is the Matrox
Millenium II graphics card. Note the difference in the contacts along the bottom
edges of the cards and the fact that the PCI card has its components on the
opposite side of the card to the ISA.
a SCSI controller (it handled one of
the hard discs and the M-O drive), a
graphics card which was good but not
spectacular, a network card and an
I/O card.
The graphics card would have to go
but I was happy with the SCSI controller and the network card. And if
I bought a new motherboard, the I/O
card would no longer be needed beAfter considerable
research and then
searching, we
purchased an AMD
200MHz K6 CPU
chip to go with the
Asus motherboard.
It offers excellent
performance and
was significantly
cheaper than the
Pentium equivalent.
There are motherboards . . . and
then there are motherboards. Today,
most use one of the Triton chipsets
and there are several of these; eg FX,
VX, HX, TX and LX. Note that only
some of these support the recently introduced high-performance SDRAM,
so choose carefully if you want to use
this type of memory.
Just how well a motherboard will
perform depends not only on which
chipset it uses but just as importantly
how clever the designers have been.
Some take shortcuts which might increase performance in one direction
but degrade it in another.
I remember only too well a mother
board I bought a few years ago which
worked perfectly well with good old
DOS. Then Windows came along
(actually Windows 3) and it simply
refused to work. I took it back to the
supplier and he swapped it, no problem at all. “We’ve had a lot of these
motherboards come back recently,”
he said. The new motherboard was
based on the same chipset but from
a different manufacturer. It ran Windows without a hitch.
After perusing various catalogs and
advertisements, I finally settled on an
“ASUS” brand motherboard costing
around $300. Although it uses the HX
chipset and doesn’t support SDRAM,
this particular board was good value
at the time. Since then of course, the
technology has moved ahead and
now, six months later, you would
probably choose one of the later models that does support SDRAM.
The processor
Everywhere you go these days you
6 Silicon Chip
hear about the marvels of the Intel
Pentium processor. They’re even advertising the things on TV! Until now,
all my computers had been based on
Intel processors but there was a new
kid on the block which was getting a
lot of attention.
AMD, a company formed by former
Intel staffers, had produced a number
of “clone” chips over the years with
little success. But its newest offering, the K6, seemed to outperform
the equivalent Pentium in just about
every test I had read. Just as importantly, the K6 offered the MMX, or
“Multimedia Extension”, capabilities
which Intel had fairly recently started
including.
If the K6 outperformed the Pentium,
how did the price stack up? It took a
bit of digging when I first started this
project (about six months ago) but
eventually I found a couple of suppli
ers who handled the K6. And, at the
time, it was significantly cheaper than
the Pentium equivalent.
That quickly made up my mind.
My new PC would have a K6 processor. That decision was the easy part.
Getting my hands on one of the little
beasties proved a lot more difficult!
No-one had, or could get, stock. A lot
of people advertised them but all had
the same story: sorry, weeks away.
I don’t know how many phone calls
I made but in the end, perseverance
paid off. Eventually, I found a supplier
who had one available because of a
cancelled order. Did I want it? I drove
across Sydney to make sure I got it!
A CPU cooling fan is essential for removing the large amount of heat generated
by high-end CPU chips. It comes complete with a male and female power plug
adaptor which allow a quick series connection to an existing power cable.
Memory
The price of memory today is a
fraction of what it was even last year.
That’s good news because most applications today appreciate every last
byte of memory you can throw their
way. In fact, some applications I use
regularly won’t even wake up with
16Mb of memory. They want 32Mb and
are even happier with 64Mb or more.
Unfortunately though, the price
of memory doesn’t increase pro-rata
with the amount of memory. 16Mb
sticks cost around $90 and 32Mb
sticks around $180. But 64Mb modules cost $600, a price increase that’s
closer to exponential! Therefore, until
the price of large memory sticks drops
even further, I’ll have to settle for the
smaller sticks.
Note that on this type of mother
board, there are four memory sockets
The CPU chip must be inserted with the correct polarity if you don’t want to see
several hundred dollars go up in smoke – literally. No force is required to insert
the chip – it is locked in place after insertion by pushing down on the lever
shown, hence the name Zero Insertion Force (or ZIF) Socket.
in two banks. Each socket in a bank
must be filled with the same type of
memory – eg, 2 x 8Mb for 16Mb. The
other bank can have different sticks
(as long as both sockets in the same
bank have the same memory).
In my case, I used 2 x 32Mb sticks
to achieve the 64Mb I wanted. Of
course, I could have chosen 4 x 16Mb
but this would have meant my future
options were cut off. As mentioned
above, I really want more memory but
having all four sockets filled would
have meant throwing memory away
in the future.
And that led to frustration No.2.
You’d think that memory would be
pretty easy to get, wouldn’t you? Not
so! When I finally placed an order, I
was told that the wholesalers were
out of stock of 32Mb modules and
weren’t getting any more for a week
or so. “We have plenty of 16Mb modules, though”.
A few phone calls to other suppliers
turned up the same story so I had to
December 1997 7
Two 32Mb “sticks” give the computer 64Mb of memory. These were inserted into the Bank 0 sockets,
while the two Bank 1 sockets were left empty. That’s for future expansion if and when memory
becomes even more affordable.
sit on my hands for several days!
Graphics card
Most “bargain” computers come
with a fairly basic graphics card.
However, if you do any serious work
involving graphics or even play
graphics-intensive games (I do the
former, not the latter) you need a gofast graphics accelerator card.
What these cards basically do is
free the computer’s CPU of a lot of
its housekeeping tasks. The CPU is
then left to do the work it’s supposed
to do, with the graphics management
handled to a large degree by the card.
The better the card, the more it can
handle and the faster the machine, at
least in general terms.
There are a lot of cards around. Once
again, after reading the reviews and
technical information, I made what
I believe is a very good choice: the
Matrox Millenium II. The model I purchased has 4Mb of memory (WRAM)
on board, with provision to expand
this to 16Mb. That’s a lot of video
memory but would be quite worth
while for some applications. The one
big sticking point is cost: you can put
64Mb of DRAM into your computer for
a lot, lot less than you can put 16Mb
of WRAM on the graphics card.
As you can see, the choice of components for my computer upgrade
has been a compromise all the way
through. Given a blank cheque, I
would simply buy the very latest
300MHz Pentium II machine with
384Mb of memory. But like most of
our readers, blank cheques don’t come
my way very often!
Anyway, after a few phone calls and
some running around, I now had the
motherboard, the graphics card and
the CPU. The new memory turned
up a week later and I was ready and
raring to go.
Out with the old
The fan was oriented so that it blows air across other heat-sensitive components
on the motherboard. This particular fan clips onto the CPU; other fans latch
onto the lugs visible on the ZIF socket.
8 Silicon Chip
The first step is to disassemble the
existing computer. Before you start attacking it with a screwdriver though,
you need to let your computer know
it’s about to have a transplant. Yes,
the computer has a brain – but it’s
not that clever!
LEFT: the “System” Icon in your control panel (click
Start, Settings, Control Panel) opens up the path to all
the information about your particular computer.
BELOW: removing devices drivers (as distinct from
physically removing the devices) from your computer is
easy: just highlight the item to be removed and then click
the Remove tab. A confirmation box comes up to make sure
you really want to do it because it’s a pretty radical step!
Click on OK and the device no longer exists.
Every time you turn on your computer, it “knows” what it has inside
it. When you add new hardware, you
need to load drivers to make that hardware work. That information stays on
the hard disc and is loaded when the
computer is “booted”.
Making wholesale changes to hardware - especially the motherboard – is
almost certain to addle the poor computer’s brain so it won’t know where
(or more correctly who) it is! The way
around this problem is to first remove
all the existing device drivers so that
the machine can rediscover its new
hardware.
To do this, you first activate the
Control Panel (via My Computer or
Start, Settings), then double-click the
System icon and select the Device
Manager tab. This presents you with
a list of the devices in your machine
and you select each one in turn and
click the Remove button.
As far as the computer is concerned,
this is a pretty radical step so it double-checks each time to make sure you
really want to do it. And, of course,
once it’s all done, the computer is no
longer usable.
The next step is to exit Windows,
turn the computer off and remove all
plugs from the back, including the
power cords. This done, the cover can
be removed and the various expansion
cards (sound, video, etc) removed by
undoing the screws on the backplane.
It’s important to handle the cards by
their edges only, to avoid any possibility of static damage to the onboard
components.
Incidentally, I’ve removed and replaced literally hundreds of cards and
motherboards over the years and have
never damaged one. No, I tell a lie –
there was that time I dropped one on
the floor and ran over it with the chair
wheel. However, I have never damaged one through static electricity.
Of course, there can always be a first
time and Mr Murphy says that it will
be either the most expensive or the
most irreplaceable card that cops it.
If at all possible, leave any cables
connected to the cards in place so
that you don t get them back-to-front
on reassembly.
In some cases, the motherboard
mounts underneath an L-shaped power supply. Usually, it can be slid out
from under the supply but we have
seen cases where it is such a tight fit
that the power supply itself must first
be removed. Fortunately, this is quite
simple – normally just four screws
hold it in place.
Typically, the motherboard will
be mounted on a number of plastic
pillars held captive in keyed slots
and will be secured by a single screw.
Once this screw is removed, you simply slide the motherboard towards the
edge of the case and then lift it out
with its stand-off pillars intact.
Clean the case
If it is more than a year or so old,
you will probably find your computer
is filthy inside. The fans do a great job
of keeping everything cool but they
December 1997 9
Here, the motherboard has been mounted in the case, ready to accept the
various I/O cards. The difference between ISA and PCI slots is clear: the four
white sockets are for PCI cards, while the three black sockets accept ISA cards.
Note that we changed the fan pictured on a previous page to one with more
power.
also suck in dust. While the computer
is disassembled give the case a good
spring clean.
Preparing the motherboard
There are only a couple of steps you
need to take here: insert the memory,
install the CPU; and set any required
jumpers on the board. OK, so that’s
really three steps. I never was good
at maths.
First start with the memory.
10 Silicon Chip
As previously discussed, memory
comes on “sticks”. These consist of a
number of memory chips on a small
PC board and are simply inserted
into the appropriate sockets on the
motherboard. This is usually just a
matter of sliding the board into the
socket at an angle and then pushing
it to near-vertical until it is held in
position by two retaining clips.
Note that each memory board has
a corner cut-out so that it can only be
inserted one way. Never try to force
memory into the socket if it doesn’t
want to go – chances are, it’s the wrong
way around.
Also note our comments before
about memory banks. The two Bank
0 sockets must each be filled with
the same type of memory, as must
the Bank 1 sockets. However, the
memory in Bank 0 can be different
to the memory in Bank 1. Normally,
the Banks are clearly identified on the
motherboard and in the manual. Note
that you must completely fill a bank
or leave it completely empty. As long
as Bank 0 is filled, Bank 1 can be left
empty or vice versa.
Now we move on to the CPU. As
we are playing with the best part of
five hundred dollar’s worth of chip,
it should be left in its protective cover until the last moment. You must
also take all the usual precautions
for handling CMOS chips; ie, don’t
touch the pins, discharge yourself to
the case, and so on.
To install the chip, first locate the
small dot or slightly angled corner
on the CPU – this aligns with a blank
area (where one hole is missing) on
the motherboard socket. Most sockets
used these days are ZIF (Zero Insertion Force) types. These have a little
lever alongside the socket which is
un
clipped and raised to allow the
CPU to be inserted. It is then lowered
and locked to hold the CPU captive
in the socket.
When the lever is raised, the CPU
should drop easily into the socket.
Because of its pin layout, the CPU
can only go in one way, so you can’t
get it wrong unless you’re completely
ham-fisted and force it in so that one
pin is bent over.
High-end CPUs such as the K6 or
Pentiums require forced air cooling,
so that they don’t run too hot. This is
achieved via a miniature fan which
clips to either the CPU or to the socket
underneath.
Smear some heatsink compound on
the fan heatsink before you place it on
the chip and then lock the connecting
clips into place. The fans which clip
to the CPU have tiny levers which
are squeezed together to force the
clips apart. The fans which clip to the
socket have a one-piece clip which
mates with lugs on the socket.
Either way, mount the fan so that
its airflow is directed across any
heat-sensitive componentry on the
motherboard – on the new motherboard we selected there were several
components with heatsinks attached
immediately alongside the CPU socket. Refer to your motherboard manual
if unsure.
The fan’s power is supplied either
from an adaptor plug/socket set which
attaches to one of your power supply
plugs or, in some cases, via a dedicated power socket on the motherboard.
If it is the latter, connect the fan
now. Otherwise, leave it until final
assembly.
Setting the jumpers
There are several sets of jumpers
on the motherboard which must be
set according to the speed and type
of your CPU.
One important setting is for the
CPU voltage – get it wrong and you
could damage the CPU. You will need
to determine the correct setting from
either the CPU itself, from documentation that comes with it or from
documentation that comes with the
motherboard.
In our case, the correct voltage for
a K6 (2.9V) was printed on the chip.
In addition, a sticker was included
with the motherboard, because the
manual made no reference to a K6
chip (the K6 was released after the
motherboard).
Another two jumpers are used to
set the bus frequency and the bus
ratio. Most motherboards today can
be set to run at a bus frequency of
50MHz, 60MHz or 66MHz, with the
CPU running at a multiple of this frequency (the bus ratio). For example,
a 200MHz CPU runs on a 66MHz bus
with a bus frequency ratio of 3 (ie, 66
x 3 = 200 or thereabouts).
It’s just a matter of setting one jumper to select the bus frequency and the
other to select the bus ratio, to set the
speed at which the CPU runs. The
details will all be listed in the manual
for your motherboard.
Incidentally, don’t be tempted to
run the CPU at a speed higher than
its designated rating – eg, a 100MHz
CPU at 2x on a 66MHz bus (equivalent
to 133MHz CPU) or even 2.5x. While
this sometimes appears to work, the
CPU was never designed to run at
this speed and often fails through
overheating. The system will also be
crash-happy.
Other jumpers on the motherboard
may also require changing, depend-
There are the various jumpers on the motherboard which need to be checked
and/or set. Go through the manual carefully to find out what’s required.
ing on your particular setup. There’s
only one way to find out and that’s
to carefully go through the manual.
seem to mate with a hole in the case,
a blind standoff might be called for.
Reassembly
What’s this? Your old cards don’t
match the slots on your new mother
board?
Over the past few years there have
been several standards for slots: 8-bit
ISA, 16-bit ISA, VESA and PCI to
name but a few. Older cards are more
likely to be ISA and most new motherboards normally have at least three
ISA slots and almost invariably they
will be 16-bit. Any 8-bit ISA cards you
want to use can be simply plugged
into half of a 16-bit slot.
VESA cards won’t fit into anything
but VESA slots and new motherboards
don’t have VESA slots, so these cards
will have to be replaced. Fortunately,
the majority of cards these days are
much cheaper than they once were.
If you are buying new cards, PCI
will give you the best performance
and compatibility. However, note
that some cards are only available as
ISA types.
Before inserting the cards, take a
few minutes to plan their location.
You can either end up with a dog’s
breakfast of cables going hither and
thither, or you can make it logical
and neat. Naturally, the more drives,
etc you have, the worse cabling will
As you might expect, reassembling
the case is basically a matter of rev
ersing your disassembly steps. But
(there’s always a but, isn’t there?)
your new motherboard may well be
a different size to your old one. Fortunately, the mounting hole locations
are standardised and you should have
no problem there. To be sure, place the
motherboard in the case and check
the line-up.
The standoffs will have to be removed from your old motherboard so
you can use them on your new one.
To remove them, grip their tops with
needle-nosed pliers and push them
through the board.
Some motherboards have an
edge-mounting standoff. This prevents the board from flexing, especially when cards are inserted into the
slots. My old board had one of these
but the components on the new board
were too close to the edge to fit this
stand-off. Other types of standoffs you
might find used include blind types
which do not fit into holes in the
case but again are designed to keep
the board straight. If you have a hole
on your motherboard which doesn’t
Card insertion
December 1997 11
ROM PCI/ISA BIOS (PI55T2P4)
PNP AND PCI SETUP
AWARD SOFTWARE, INC.
Slot1 (RIGHT) IRQ
Slot 2 IRQ
Slot 3 IRQ
Slot 4 (LEFT) IRQ
PCI Latency Timer
: Auto
: Auto
: Auto
: Auto
: 32 PCI Clock
DMA 1 Used By ISA : Yes
DMA 3 Used By ISA : No/ICU
DMA 5 Used By ISA : No/ICU
IRQ 3 Used By ISA
IRQ 4 Used By ISA
IRQ 5 Used By ISA
IRQ 7 Used By ISA
IRQ 9 Used By ISA
IRQ 10 Used By ISA
IRQ 11 Used By ISA
IRQ 12 Used By ISA
IRQ 14 Used By ISA
IRQ 15 Used By ISA
: No/ICU
: No/ICU
: Yes
: No/ICU
: No/ICU
: Yes
: No/ICU
: No/ICU
: No/ICU
: No/ICU
NCR SCSI BIOS
USB function
ISA MEM Block BASE : No/ICU
: AUTO
: Disabled
ESC : Quit
↑ ↓ → ← : Select Item
F1 : Help
PU/PD/+/- : Modify
F5 : Old Values (Shift)F2 : Color
F6 : Load BIOS Defaults
F7 : Load BIOS Defaults
Fig.1: if you have non Plug’n’Play ISA (legacy) cards, then you need to reserve
their IRQ assignments in a section of the CMOS setup labelled “PnP and PCI
Setup” (or similar), as this screen mock-up shows. This prevents a PNP
operating system such as Windows 95 from attempting to assign those IRQs
to PnP cards. In this case, IRQs 5 and 10 have been reserved for ISA non-PnP
cards.
be. But at least plan it to look as good
as it can be.
When inserting cards, make sure
that they are fully inserted into the
slot at both ends. They sometimes
look like they are in, but one end is
not quite seated. At best, the card
won’t work. At worst, you could do
some damage.
Always make sure the card is
secured to the backplane with the
appropriate screw. And if you manage to drop a screw onto the motherboard, make sure you fish it out
immediately. Don’t put it off until
later – it’s easy to forget and could
easily short components or tracks
together later on.
Traps for young players
The major problem people have
when assembling (or reassembling) a
computer is the cabling. Would you
believe it was also the only problem I
had? And that was after having done
this job many times before – and being
wary of the problem!
The first job is to fit the power
plugs to the motherboard. There are
two plugs which must be inserted the
right way around. Simply remember
that black goes to black – there are
black wires on both plugs and these
12 Silicon Chip
go together. The plugs insert one way
around only and as long as black goes
to black you’ll get it right.
If you haven’t removed the plugs
from your cards, you shouldn’t have
any problems. But if you have, be
aware that most cables with IDC
plugs can be inserted two ways: (1)
the way that works; and (2) the way
that doesn’t!
Almost invariably, pin 1 is the
pin with the red stripe. And usually
(though not always), pin 1 is marked
on the motherboard. If it isn’t you may
need to refer to your manual.
Finally, make sure that all cables are
seated completely. This is where we
got into trouble: none of the CD-ROM
drives worked when the machine was
turned on. After much frustration, it
turned out that the connector was
lifted very slightly off the motherboard socket at one end, which meant
that some of the pins weren’t making
contact. It looked OK but it wasn’t –
pushing the connector hard on solved
the problem.
Setting up the system
If you have only swapped the
motherboard and left every
t hing
else basically intact, you shouldn’t
have to go through the rigmarole of
reinstalling Windows 95. However,
if you change hard discs at the same
time, then you will have to reinstall
the operating system on the new
disc. These days, you don’t have to
tell the CMOS what your hard discs
are – with modern mother
boards,
they are auto-detected!
A modern motherboard will have
a “Plu
g’n’Play” (PnP) BIOS. When
it was first introduced, this earned
the nickname “Plug’n’Pray” because
it didn’t always work exactly as it
should. These days, though, a PnP
BIOS generally works quite well, although some of the cheaper expansion
cards can sometimes cause problems.
However, most problems with PnP
occur when you mix old style (ie,
“legacy”) ISA cards and PnP cards.
Legacy cards are cards on which
you manually set the IRQ (interrupt
request) assignment and any other
resources required by the card (eg,
the memory I/O range). This can be
done by using on-board jumpers or
by means of a software setup utility.
The problem is that a PnP operating
system such as Windows 95 doesn’t
automatically detect any IRQs that
have been set in this manner. As a
result, it may try to automatically
assign an IRQ that has been taken by
a legacy card to a PnP card. The result
is a resource conflict with either one
or both cards not working properly.
Reserving IRQs
Fortunately, there’s any easy answer to this problem. The trick is
first write down the IRQs that have
been assigned to the legacy cards and
then go into your CMOS setup and
reserve these IRQs so that the operating system cannot grab them. You
normally do this via a section of the
CMOS labelled “PnP and PCI Setup”
or similar – see Fig.1.
For example, if you install a legacy
ISA card that requires IRQ 10, then
you change the setting for the line
“IRQ 10 Used By ISA” from “No/ICU”
to “Yes”. Note that the screen mock-up
shown in Fig.1 is for an Award BIOS.
Your BIOS may show a somewhat
different arrangement but the basic
principle is still the same.
Note that you may also have to
reserve DMA channels for legacy ISA
cards (especially sound cards). Check
the manual for the device to find out
its requirements.
Once the IRQs have been reserved,
This window is accessed by double clicking the System
Icon then the Device Manager tab. It presents you with
a list of everything in your computer – as far as your
computer is concerned. Double clicking on any item with
a “+” symbol reveals the individual devices being
controlled, along with any conflicts.
the remaining IRQs will be automatically assigned to the PnP devices
and there should be no conflicts. To
check this, open Control Panel (via
“Start” and “Settings”) and then double-click the System icon. Select the
Device Manager tab and you will see
a list of devices in your machine. If
there are any conflicts, you will see a
yellow exclamation mark next to the
particular device.
If any devices are conflicting, click
the Details button to find out which
device is causing the problem. If
you haven’t reserved the IRQ for the
legacy card in the system BIOS, then
doing so should solve the problem.
Alternatively, try setting the legacy
card to an unused IRQ and don’t forget
to reserve this in the system BIOS so
that it cannot be grabbed by another
card that’s added in later.
Note that there are some IRQs
which are used by certain devices by
convention. If at all possible, these
conventions should be maintained to
avoid future conflicts.
Finally, if you get yourself into a
In this case we’ve double-clicked on the SCSI
Controllers entry to reveal all the information we
need to know about our SCSI controller; ie, its
settings, the driver it uses, addresses, IRQs and so
on. Fortunately, we have no conflicting devices but
if we did, this screen would show them.
Double Click on the Computer Icon in the System Properties
window and you can see which interrupt request (IRQ)
assignments are used in your computer, and by what. You
can also check the I/O (input output) settings, DMA settings
and the memory being used by that device.
mess, try starting off with a “barebones” system (ie, as much as you
need to get the computer started) and
then add the expansion cards in one
at a time. Get each card going prop-
erly before adding the next. Provided
you approach the job in a methodical
manner, you should be able to get
everything up and running without
SC
too many hassles.
December 1997 13
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