In these days of commodity parts and
component pricing, building your own system from scratch is no
longer the daunting process it once was. Every component
necessary to build a PC-compatible system is available off the
shelf, and at very competitive pricing. In many cases, the
system you build can use the same components as the top
name-brand systems.
There are, however, some cautions. The
main thing to note is that you rarely save money when building
your own system compared to purchasing a complete system from
a mail order vendor or mass merchandiser. The reasoning for
this is simple: Most system vendors today who build systems to
order use many if not all the same components you can when
building your own. The difference is that they buy these
components in quantity and receive a much larger discount than
you can purchasing only one of a particular item.
There also is only one shipping or
handling charge when you purchase a complete system instead of
the individual shipping charges when you purchase separate
components. In fact, the shipping, handling, and even phone
charges from ordering all of the separate parts needed to
build a PC often add up to $100 or more. This cost rises if
you encounter problems with any of the components and have to
make additional calls or send improper or malfunctioning parts
back for replacement.
It is clear that the reasons for
building a system from scratch often has less to do with
saving money than with the experience and end result. In the
end, you have a custom system that contains the exact
components and features you have selected. The experience
itself is also very rewarding. You know exactly how your
system is constructed and configured because you have done it
yourself. This makes future support and installation of
additional accessories much easier.
It may be possible to save some money
using components of your current system when building your new
system. You might have recently upgraded your hard drive or
memory in an attempt to extend the life of your current
computer. You can take those components with you to the new
system in most cases, if you plan appropriately. For example,
if you used 30-pin SIMMs in your old system, you can buy a new
motherboard that supports both 72- and 30-pin SIMMs, or buy a
SIMM adapter to convert your 30-pin SIMMs to 72.
So if you are interested in a rewarding
experience, want to have a custom system that is not exactly
offered by any vendor, want to save some money by re-using
some of the components from your current system, and you are
not in a hurry, then building your own PC-compatible may be
the way to go. On the other hand, if you are interested in
getting a PC-compatible for the best price, want one-stop
support for warranty claims, and need an operational system
quickly, then building your own system should definitely be
avoided!
This chapter details the components
needed to assemble your own system, explains the assembly
procedures, and lists some recommendations for components and
their sources.
System
Components
The components used in building a
typical PC compatible are:
- Case and power supply
- Motherboard:
Processor |
Parallel |
Memory |
IDE |
Serial |
Floppy |
- Floppy disk drive
- Hard disk drive(s)
- CD-ROM drive
- Keyboard and pointing device
(mouse)
- PCI video card and
display
- Sound card and
speakers
- Accessories:
Heat sinks/cooling fans |
Hardware |
Cables |
Operating system
software |
- Heat sinks/cooling
fansHardwareCablesOperating system softwareEach of these
components is discussed in the following sections.
Case and Power
Supply
The case and power supply is usually
sold as a unit. There are several designs to choose from, most
of which will take a standard Baby-AT or the new ATX form
factor mother-boards. The size of the case, power supply, and
even the motherboard are called the form factor. The
most popular case form factors are as follows:
- Full Tower
- Desktop
- Mid-Tower
- Low Profile (also called
Slimline)
- Mini-Tower
Out of these choices, it is recommended
that you avoid the Low Profile systems. These cases require a
special type of motherboard called a Low Profile or
LPX board. LPX motherboards have virtually everything
built in, even video, and do not have any normal adapter
slots. Instead, all of the expansion slots are mounted on a
"tree" board called a riser card, which plugs into a
special slot on the motherboard. Adapter cards then plug
sideways into the riser card, making expansion somewhat
limited and difficult.
Most of the case designs other than the
Low Profile (or Slimline) take a standard sized motherboard
called a Baby-AT type. This designation refers to the
form factor or shape of the motherboard, which is to say that
it mimics the original IBM AT but is slightly smaller.
Actually, the Baby-AT form factor is a kind of a cross between
the IBM XT and AT motherboard sizes.
Many of the newer cases accept the
standard Baby-AT form factor motherboards as well as the
ATX-style boards, but an older case designed for Baby-AT
motherboards does not accept an ATX motherboard. The
ATX form factor will eventually replace the Baby-AT style for
most newer motherboards. So if you are interested in the most
flexible type of case and power supply that will support
future upgrades, look for a unit that conforms to the ATX and
Baby-AT motherboard form factors.
Whether you choose a desktop or one of
the tower cases is really a personal preference. Most feel
that the tower systems are easier to work on, and the
full-sized tower cases have lots of bays for different storage
devices. Tower cases have enough bays to hold floppy drives,
multiple hard disks, CD-ROM drives, tape drives, and anything
else you might want to install. Some of the desktop cases also
can have as much room as the towers, particularly the mini- or
mid-tower models. In fact, a tower case can really be
considered a desktop case turned sideways or vice versa. Some
cases are convertible-- that is, they can be used in either a
desktop or tower orientation.
Motherboard
There are several compatible form
factors used for motherboards. The form factor refers to the
physical dimensions and size of the board, and dictates what
type of case the board will fit into. The types of motherboard
form factors generally available are the following:
- Full-size AT
- ATX
- Baby-AT
- LPX
The full-size AT motherboard is so
named because it matches the original IBM AT motherboard
design. This allows for a very large board of up to 12 inches
wide by 13.8 inches deep. The keyboard connector and slot
connectors must conform to specific placement requirements to
fit the holes in the case. This type of board will fit into
the tower or full-sized desktop cases only. Because the cases
that will fit these boards are more limited in availability,
and due to component miniaturization, the full-size AT boards
are no longer being produced by most motherboard
manufacturers.
The Baby-AT form factor is essentially
the same as the original IBM XT motherboard, with
modifications in screw hole positions to fit into an AT-style
case (see Figure 19.1). These motherboards also have specific
placement of the keyboard connector and slot connectors to
match the holes in the case.
NOTE: Virtually all full size AT
and Baby-AT motherboards use the standard 5-pin DIN type
connector for the keyboard. Baby-AT motherboards will fit
into every type of case except the Low Profile or Slimline
cases. Because of their flexibility, this is now the most
popular motherboard form factor. Figure 19.1 shows the
dimensions and layout of a Baby-AT motherboard.
The newest form factor on the market
today is the ATX form factor, which was released by Intel in
July 1995 (see Figure 19.2). This motherboard design is
featured on many new Pentium and Pentium Pro-based
motherboards and should continue to be featured over the next
few years, and it is destined to replace the Baby-AT form
factor. ATX-shaped boards are the same basic dimensions as
Baby-AT; however, they are rotated 90 degrees from the
standard Baby-AT orientation. This places the slots parallel
to the short side of the board, allowing more space for other
components without interfering with expansion boards.
Components that produce large amounts of heat, such as the CPU
and memory, are located next to the power supply, which is
redesigned to feature an internal fan blowing directly across
the board.
The ATX-style power supply also
features a redesigned single keyed (foolproof!) connector that
cannot be plugged in backwards, and it also supplies the
motherboard with 3.3v for many of the newer CPUs and other
components.
Consider that if you don't purchase an
ATX form factor motherboard this time, the next time you
probably will! Virtually all motherboard manufacturers have
committed to the new ATX design in the long run, as the ATX
motherboard designs will be cheaper, easier to access for user
serviceability, and more reliable.
Other form factors used in motherboards
today are the LPX and Mini-LPX form factors. These form
factors require the use of a Low Profile case and are normally
not recommended when building your own system. This is due to
the number of different variations on case and riser card
designs. These types of form factors are popular with many of
the PC systems sold through retail outlets and appliance
stores.
FIG.
19.1 Baby-AT motherboard form
factor.
TIP: There can be some
differences between systems with LPX motherboards, so it is
possible to find interchangability problems between
different motherboards and cases. I usually do not recommend
LPX style systems if future upgradability is a factor; it is
not only difficult to locate a new motherboard that will
fit, but LPX systems are also limited in expansion slots and
drive bays as well. Generally, the Baby-AT configuration is
the most popular and the most flexible type of system to
consider.
Besides the form factor, there are
several other features you should consider in a motherboard.
The primary considerations would be the processor type and
chipset. Motherboards you should consider would have a socket
for one of three different processor families:
- Pentium
- Pentium with MMX (MultiMedia
eXtension)
- Pentium Pro
- Pentium II
FIG.
19.2 ATX motherboard form
factor.
Pentium motherboards will normally have
a Zero Insertion Force (ZIF) Socket 7 (321-pin), which is
available in speeds from 120MHz to 233MHz. MMX is an
extension of the Pentium line that includes additional
instructions to handle and accelerate multimedia function
calls, such as video and sound. The Pentium II is to the
Pentium Pro as the Pentium with MMX is to the Pentium. The
Pentium II processor is Intel's newest processor family and is
becoming a popular alternative among the highest end systems
that run full 32-bit OSes, for example, Windows NT.
Depending on the exact processor
version you install and the speed at which it is to be run,
there may be jumpers on the motherboard to set. There may also
be jumpers to control the voltage supplied to the processor;
these should be carefully checked or the board and processor
will not operate properly.
There are a few other items to consider
when purchasing a motherboard. Besides the processor, the main
component on the board would be the chipset. This is
normally a set of one to five chips that contain the main
motherboard circuits. These chipsets replace the 100 or more
discrete components that were used in the original IBM AT
systems, and allow a motherboard designer to easily create a
functional system. The chipset will contain the local bus
controller (usually PCI), the cache controller, main memory
controller, DMA and Interrupt controllers, and several other
circuits as well. The chipset used in a given motherboard will
have a profound effect on the performance of the board, and
will dictate performance parameters and limitations such as
cache size and speed, main memory size and speed, processor
types and speeds, and more.
Because chipsets are constantly being
introduced and improved over time, I cannot possibly list all
of them and their functions, but as an example, I will discuss
some of the popular ones for Pentium-based systems. There are
several very popular high performance chipsets designed for
Pentium motherboards on the market today. The best of these
offer support for EDO (Extended Data Out) RAM, pipeline burst
cache SRAM (Static RAM), PCI local bus, and Advanced Power
Management (APM), as well as other functions, such as IDE
interfaces.
Here are several of the
high-performance chipsets available for Pentium-based
motherboards:
- Intel Triton/Triton II. The
82430FX PCIset (called Triton) and HX (called Triton II) are
both four chipsets. The Triton chipset consists of the
82437FX Triton System Controller (TSC), two 82438FX Triton
Data Paths (TDP), and the 82371FB PCI ISA IDE Xcelerator
(PIIX). The TSC integrates the cache and main memory control
functions and provides bus control for transfers between the
CPU, cache, main memory, and the PCI Bus. The L2 cache
controller in the TSC supports write-back cache for cache
sizes of 256 and 512K, as well as lower cost cacheless
designs. Cache memory can be implemented with either
standard, burst, or pipeline burst SRAMs. The TSC and TDPs
together support up to 128M of EDO or standard main memory.
The PIIX acts as a PCI to ISA bridge, and includes the DMA
controllers, interrupt controllers, timer/counter, power
management support, and an Enhanced IDE interface with up to
two IDE connectors for four IDE devices.
NOTE: The original (FX suffix)
version Triton chipset unfortunately does not support
parity-checked RAM. This means that any motherboard built
with this chipset will not be able to detect memory errors
during system operation. Even if you purchase parity SIMMs,
the parity will not be used. Many system integrators will
not use non-parity RAM in mission-critical systems, such as
file servers. Because of market pressures demanding such
support, Intel has released a second-generation (HX suffix)
Triton II chipset that includes both parity and ECC (Error
Correcting Code) memory support.
- Opti Viper. The 82C550
Viper-DP from Opti supports not only the Pentium, but the
AMD K5 and Cyrix M1 processors as well, in both single and
dual processor configurations. The Viper-DP chipset consists
of three chips: the 82C556 Data Buffer Controller (DBC), the
82C557 System Controller (SC), and the 82C558 Integrated
Peripherals Controller (IPC). The SC is the main chip and
contains the main memory controller, L2 cache controller,
and the PCI and VL-Bus interfaces. The IPC contains the ISA
bus controller, DMA and Interrupt controllers, and PCI to
ISA bridge. The DBC buffers the CPU and main memory and
contains the parity generation and checking circuits. Viper
supports up to 512M of EDO or standard main memory with or
without parity checking, and up to 2M of L2 write-back cache
using either asynchronous, burst, or pipeline burst
SRAMs.
- ALI Aladdin. The Aladdin
M1510 chipset from Acer Laboratories Inc. also supports the
Pentium, AMD K5, and Cyrix M1 series processors in both
single and dual processor configurations. Aladdin M1510 is a
four-chip set. It includes the M1511 Memory/Cache Controller
that supports EDO RAM as well as standard RAM up to 768M
with or without parity checking.
- This chip also supports up to 1M of
L2 write-back cache, including support for standard burst
and pipeline burst SRAMs. The M1513 System I/O Controller
contains the PCI bus interface, DMA and Interrupt
controllers, timer circuits, and PCI Enhanced IDE interface,
as well as an integrated keyboard controller. Finally, two
M1512 data buffers are used to serve as an intermediate
between the CPU and main memory.
The choices for Pentium II motherboard
chipsets are a little more restricted. As of this printing,
only a couple of chipsets are available, including the Intel
Orion and Natoma chipsets. Intel's original Pentium Pro
(Pentium II without MMX support) chipset was code-named Orion
and is technically known as the 82450GX or KX. This chipset is
generally made up of seven individual chips and supports up to
four Pentium Pro processors and two separate PCI buses in the
GX server version. A desktop version of Orion, the 82450KX,
supports two processors and a single PCI bus.
More recently, Intel released a less
expensive and more efficient Natoma chipset for Pentium Pro
machines. Natoma is technically called the 82440FX chipset and
consists of only three chips rather than seven as with Orion.
Natoma supports only two Pentium Pro processors and a single
PCI bus, making it less suited to servers than the GX version
of the Orion chipset. However, the greater internal efficiency
of Natoma makes it a better performer overall than
Orion.
No matter what Pentium class chipset
you look for, I would recommend looking for the following
supported features:
- EDO RAM (main memory)
- Pipeline Burst (also called
Synchronous) SRAM cache
- Parity generation and
checking
- ECC memory support
- APM (Advanced Power Management)
energy saving functions
- MMX support (if you plan to do any
multimedia)
- PCI Local Bus
Most of the better Pentium chipsets on
the market today should have these features. If you are buying
a motherboard, I highly recommend you contact the chipset
manufacturer and obtain the documentation (usually called the
Data Book) for your particular chipset. This will
explain how the memory and cache controllers, as well as many
other devices in your system, operate. This documentation will
also describe the Advanced Chipset Setup functions in your
system's Setup program. With this information, you may be able
to fine-tune the motherboard configuration by altering the
chipset features. Because chipsets are discontinued and new
ones are introduced all the time, don't wait too long to get
the chipset documentation, as most manufacturers only make it
available for chips currently in production.
NOTE: One interesting tidbit
about the chipset is that in the volume that the motherboard
manufacturers purchase them, the chipsets usually cost about
$40 each. If you have an older motherboard and need repair,
you normally cannot purchase the chipset because they are
normally not stocked by the manufacturer after they are
discontinued. The low-cost chipset is one of the reasons
mother-boards have become disposable items and are rarely,
if ever, repaired.
Another feature on your motherboard
will be the BIOS (Basic Input/Output System). This is
also called the ROM BIOS because the code is stored in
a Read Only Memory (ROM) chip. There are several things to
look for here. One is that the BIOS be supplied by one of the
major BIOS manufacturers such as AMI (American Megatrends
International), Phoenix, Award, or Microid Research. Also,
make sure that the BIOS is contained in a special type of
reprogrammable chip called a Flash ROM or EEPROM
(Electrically Erasable Programmable Read Only Memory).
This will allow you to download BIOS updates from the
manufacturer and, using a program they supply, easily update
the code in your BIOS. If you do not have the Flash ROM or
EEPROM type, you will have to physically replace the chip if
an update is required.
Make sure that the motherboard and BIOS
support the new Plug and Play (PnP) specification. This will
make installing new cards, especially PnP cards, much easier.
PnP automates the installation and uses special software that
is both built in to the BIOS as well as the operating system
(such as Windows 95) to automatically configure adapter cards
and resolve adapter resource conflicts.
Processor
In most cases, your motherboard comes
with the processor already installed. Most of the name-brand
motherboard manufacturers like to install the processor and
warranty the board and processor as a unit. This is not always
the case, and it is definitely possible to purchase the
motherboard and processor separately.
The processor normally is installed in
a special ZIF socket on the motherboard. Make sure the jumpers
on the board are set to match the correct processor type,
speed, and voltage.
Memory
Your system will require memory for the
Level 2 (secondary) cache as well as the main memory. The
cache memory will be in the form of individual SRAM chips, or
possibly in what is called COAST (Cache On A Stick) or
CELP (Card Edge Low Profile). COAST and CELP are
different names for the same thing. This is a new standard for
cache SIMMs. COAST/CELP SIMMs have a different number of pins
and pinout from standard main memory SIMMs, and are not
interchangeable with them.
Most Pentium motherboards support at
least 256-512K of cache memory. The chips themselves are
available in three basic cache types: standard asynchronous,
burst, and pipeline burst. The latter offers the highest
performance; choose it if your motherboard supports it. Most
of the newer Pentium boards support the pipeline burst cache
chips; most of the 486 boards didn't. This is because these
faster cache chips are not really needed at the slower 33 to
40MHz memory bus speeds on the 486 compared to the 60 and
66MHz memory bus speeds in a Pentium system.
Main memory will normally be installed
in the form of SIMMs (Single Inline Memory Modules) or
in some cases the newer DIMMs (Dual Inline Memory
Modules). There are three different physical types of main
memory modules used in PC systems today, with several
variations of each. The three main types are as follows:
- 30-pin SIMMs
- 72-pin SIMMs
- 168-pin DIMMs
The 72-pin SIMMs are by far the most
common type of memory module used today; however, just a few
years ago most systems came with 30-pin modules. Many of the
high-end systems use the DIMMs, because they are 64-bits wide
and can be used as a single bank on a Pentium or Pentium Pro
system. Depending on the type of processor, a different number
of SIMMs must be installed to make a complete memory bank, and
the 72-pin SIMMs are four times as dense as the 30-pin
types.
For example, in a 486-based system, you
would need four 30-pin SIMMs to make a single bank of memory,
while only one 72-pin SIMM would be required for a single
bank. This is because the 72-pin SIMMs hold data 32 bits wide,
while the 30-pin SIMMs only hold data 8 bits wide. A 64-bit
Pentium system, then, would require two 72-pin SIMMs or a
single 168-pin DIMM to make a single bank.
Memory modules can include an extra bit
for each eight to be used for parity checking. These are
called parity SIMMs or parity DIMMs and are
required by most older boards. Many newer motherboards do not
employ parity checking, which means that you will not be able
to use the slightly more expensive parity SIMMs. You can
install them, but the extra parity bits will not function. I
do not necessarily agree with this philosophy, but
nevertheless, many newer motherboards (such as those based on
the Intel Triton chipset) simply cannot use parity checking at
all! Most other chipsets, including the newer Triton II, do
support memory parity checking.
Another thing to watch out for is the
type of metal on the memory module contacts. They are
available with either tin- or gold-plated contacts. While it
may seem that gold-plated contacts are better (they are), you
should not use them in all systems. You should instead always
match the type of plating on the module contacts to what is
also used on the socket contacts. In other words, if the
motherboard SIMM or DIMM sockets have tin-plated contacts,
then you must use SIMMs or DIMMs with tin-plated
contacts also.
If you mix dissimilar metals (tin with
gold), there will be a rapidly accelerated corrosion occurring
on the tin side, and also tiny electrical currents will be
generated. The combination of the corrosion and tiny currents
causes havoc, and all types of memory problems and errors
occur. In some systems, I have observed that everything will
seem fine for about a year, during which the corrosion
develops. After that, random memory errors result. Removing
and cleaning the memory module and socket contacts postpones
the problem for another year, upon which the problems return
again. How would you like this problem if you had 100 or more
systems to support? Of course you can avoid these problems if
you insist on using SIMMs with contacts whose metal matches
the metal found in the sockets in which they will be
installed.
Finally, some systems now use a special
type of memory called EDO (Extended Data Out). These
memory chips are slightly redesigned and do not cost much more
than standard non-EDO memory, but they can operate at
increased efficiency in a motherboard designed for them. The
actual speed increase varies but is usually not more than a
couple of percentage points. Motherboards that use EDO memory
also can use standard non-EDO memory, but they will not enjoy
the increased performance. You also can install EDO memory in
older systems that do not support it because EDO is
backward-compatible with standard (called fast page
mode) memory. Of course, installing the more expensive EDO
modules in an older system will not improve performance.
I/O
Ports
Most motherboards today have built-in
I/O ports. If these ports are not built-in, then they will
have to be supplied via a plug-in expansion board that
unfortunately wastes a slot. The following ports should be
included in any new system you assemble:
- Mouse port (so-called PS/2
type)
- Two local bus Enhanced IDE ports
(primary and secondary)
- Floppy controller (2.88M
capable)
- Two serial ports (16550A buffered
type)
- Parallel port (EPP/ECP type)
The standard procedure is to include
these ports directly on the motherboard. This is possible
because there are several chip companies that have implemented
all of these features except the mouse port (which uses the
keyboard controller) on a single Super I/O chip! These chips
often cost less than $5 in quantities of 1,000 or more, so
adding these items directly to the motherboard saves a more
expensive board taking up an expansion slot.
If these devices are not present on the
motherboard, then various Super or Multi-I/O boards are
available that implement all of these ports. Again, most of
the newer versions of these boards use a single chip
implementation because it is cheaper and more reliable.
Floppy Disk
Drive
Obviously, your system needs some type
of floppy drive to load software. Usually, this is a 1.44M 3
1/2-inch drive, but I normally recommend a 2.88M drive these
days. The 2.88M drives are superior to the 1.44M drives, and
they are fully backward-compatible. Most current controllers
and ROM BIOS fully support the 2.88M drives.
If you are interested in a 5 1/4-inch
drive, most of the floppy drive manufacturers make combo
drives that include both a 3 1/2-inch 1.44M and 5 1/4-inch
1.2M drive in a single unit, which installs in a half-height 5
1/4-inch bay. At least one company (Teac) offers a combo drive
that combines a 1.44M floppy and a quad-speed CD-ROM drive in
a single unit as well. One drawback of these combo units is
that if one of the components fails, the entire combo drive
has to be replaced. Also, no one seems to make these with the
more desirable 2.88M floppy drives.
Hard Disk
Drive
Your system also needs a hard disk. In
most cases, a drive with a minimum capacity of 1.6G is
recommended, although in some cases you can get away with less
for a low-end configuration; you will be hard pressed to find
one smaller. High-end systems should have drives of 2-4G or
higher. The most popular interface is IDE, although SCSI is
preferred for multitasking OSes. IDE generally offers greater
performance for single installations, but SCSI is better for
two or more drives or with multitasking operating systems like
Windows 95 and NT. This is due to the greater intelligence in
the SCSI interface, which relieves some of the I/O processing
from the CPU in the system.
There are several brands of drives to
choose from, but most of them offer similar performance within
their price and capacity categories.
CD-ROM
Drive
A CD-ROM drive should be considered a
mandatory item in any PC you construct these days. This is
because most software--particularly multimedia programs--is
now being distributed on CD-ROM. Systems can now boot from
CD-ROM drives (Windows NT 4.0, for example). There are several
types of CD-ROM drives to consider these days, but mostly I
recommend a minimum of f a quad-speed drive interfaced via an
IDE connection. This results in the best possible performance
with the minimum amount of hassle. If you already have a SCSI
adapter, go with a SCSI CD-ROM as well; you'll improve your
multitasking performance and save money on an unneeded IDE
controller.
Keyboard and
Pointing Device (Mouse)
Obviously, your system needs a keyboard
and some type of pointing device, such as a mouse. Different
people prefer different types of keyboards, and the "feel" of
one type can vary considerably from other types. I suggest
that you try a variety of keyboards until you find what suits
you best. I prefer a stiff action with tactile feedback
myself, but others prefer a lighter, quieter touch.
Because there are two types of keyboard
connectors found in systems today, make sure that the keyboard
you purchase matches the connector on your motherboard. Most
Baby-AT boards use the larger 5-pin DIN connector, and most
ATX boards use the 6-pin, mini-DIN connector; however, the
trend now seems to be changing to the mini-DIN connector for
all boards. On some motherboards, you have an option of
choosing either connector when you purchase the board. If you
end up with a keyboard and mother-board that do not match,
there are several companies that sell adapters to mate either
type of keyboard to either type of motherboard
connector.
The same concept applies to mice or
other pointing devices; there are a number of different
choices that suit different individuals. Try several before
deciding on the type you want. If your motherboard includes a
built-in mouse port, make sure that you get a mouse that is
designed for that interface. This mouse is often called a
PS/2 type mouse because the IBM PS/2 systems introduced
this type of mouse port. Many systems use a serial mouse
connected to a serial port, but having a
motherboard-integrated mouse port would be better because you
would have both serial ports free for other devices.
TIP: You might be tempted to
skimp here to save a few dollars. Don't. You do all of your
interacting with your new PC through these devices, and
cheap ones make their presence known every time you use your
system.
Video Card and
Display
You need a PCI video adapter as well as
a monitor or display to complete your system. There are
numerous choices in this area, but the biggest piece of advice
I have is to choose a good monitor. The display is your main
view to the system and can be the cause of many hours of
either pain or pleasure, depending on what monitor you
choose.
I usually recommend a minimum of a
17-inch display these days. Anything smaller cannot acceptably
display 1,024x768 pixel resolution. If you opt for a 15-inch
or smaller display, you might find that the maximum tolerable
resolution would be 800x600. This may be confusing, because
most 15-inch monitors claim to be able to display 1,024x768
resolution or even higher, but the characters and features are
so small on-screen at that resolution that excessive eyestrain
and headaches will result. If you spend a lot of time in front
of your system and want to display the higher resolution, a
17-inch display should be considered mandatory.
Your video card and monitor should be
compatible in terms of refresh rate, and a minimum refresh
rate for a solid, nonflickering display is 70-72Hz; the higher
the better. If your new video card can display 16 million
colors at a resolution of 1,024x768 and a refresh rate of
76Hz, your monitor's maximum refresh rate at 1,024x768 is
56Hz, and you can't use the video card to its maximum
potential.
Sound Card and
Speakers
You need a sound card and a set of
external speakers for any system that is to be multimedia
capable. The sound card should be compatible with the Creative
Labs Sound Blaster cards, which have set the standards in this
area. Getting a sound card with an upgradable memory (the same
SIMMs you use for your main memory) enables you to download
additional sound samples--speaker size and quality are up to
you.
Accessories
Often you need various accessories to
complete your system. These are the small parts that can make
or break the assembly process.
Heat Sinks/Cooling
Fans
Most of today's faster processors
produce a lot of heat, and this heat has to be dissipated or
your system will operate intermittently or even fail
completely. Heat sinks are available in two main types:
passive and active.
Passive heat sinks are simply
finned chunks of metal (usually aluminum) that are clipped or
glued to the top of the processor. They act as a radiator, and
in effect give the processor more surface area to dissipate
the heat. I normally recommend this passive design type of
heat sink because there are no mechanical parts to fail. In
some cases, you should use a thermal transfer grease or sticky
tape to fill any air gaps between the heat sink and the
processor. This allows for maximum heat transfer and the best
efficiency.
An active heat sink includes a
fan. These can offer greater cooling capacity than the passive
types, but require power and are not known for reliability.
They often use a cheap fan mechanism that fails after a year
or so, thus allowing the processor to overheat and the system
to fail. If you do use an active heat sink with a fan, stay
away from cheaper units that may be more failure prone.
NOTE: Notice that the newer ATX
form factor motherboards are designed to eliminate the
troublesome and unreliable active heat sink (CPU fan). These
systems feature a power supply with reverse flow cooling
that blows air directly over the CPU, which is relocated in
these systems to take advantage of this. Due to a superior
design, the ATX motherboard form factor eliminates the need
for any sort of cooling fan mounted directly to the CPU.
Cables
Any PC system needs a number of
different cables to hook everything up. These can include
power cables or adapters, disk drive cables, CD-ROM cables,
and many others. Most of the time, the devices you purchase
come with included cables, but in some cases they aren't
supplied. The vendor list in Appendix A of this book has
several cable and small parts suppliers listed that can get
you the cables or other parts you need to complete your
system.
Another advantage of the ATX
motherboard form factor is that these boards feature
externally accessible I/O connectors directly mounted to the
rear of the board. This eliminates the "rat's nest" of cables
found in the common Baby-AT form factor systems. This feature
also makes the ATX system a little cheaper and more reliable
as well.
Hardware
You need screws, standoffs, and other
miscellaneous hardware to assemble your system. Most of this
comes with the case, but in some situations you may need more.
Again, you can consult the vendor list in Appendix A for
suppliers of small parts and hardware needed to get your
system operational.
Operating System Software. You
need OS software such as DOS, Linux, or Windows to run your
PC. Most software houses carry a selection of appropriate
operating system software and any applications you need.
System
Assembly
Actually assembling the system is easy
after you have lined up all of the components! In fact, you
may find the procurement phase the most lengthy and trying of
the entire experience. Completing the system is simply a
matter of screwing everything together, plugging in all of the
cable and connectors, and configuring everything to operate
properly together.
More explicit instructions for
installing any of the system components can be found in the
section of this book that covers that particular component.
For example, to find out about configuring and installing the
floppy drive, consult Chapter 13, "Floppy Disk
Drives."
In short order, you will find out
whether your system operates as you had planned, or whether
there are some incompatibilities between some of the
components. Be careful and pay attention to how you install
all of your components. It is rare that a newly assembled
system operates perfectly the first time, even for those who
are somewhat experienced. It is easy to forget a jumper,
switch, cable connection, and so on, which would cause
problems in system operation. The first reaction if there are
problems is to blame the problem on defective hardware, but
that is usually not the case. Usually the problem can be
traced to some missed step or error made in the assembly
process.
Sources and
Suppliers
One of the most valuable (to me anyway)
parts of this book is the vendor list in Appendix A. Here you
will find a number of vendors of different PC components,
including addresses, phone numbers, and other information as
it is available. These vendors are in this list usually
because I recommend their products, or because they are an
important company whose products are very popular. There are
companies in the vendor list covering all of the components
needed to build your system. In some cases, the manufacturers
of the components listed will not sell direct to end users,
and you may find yourself purchasing through a distributor
instead. That is okay; I normally include the actual
manufacturers in my list because they can best recommend a
distributor for their own products, and of course they should
support their own products as well.
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