MAKING A CASE FOR CASES

When considering cases, there are four things that come to mind:

  • Orientation
  • Capacity
  • Form factor
  • Convenience

 

Orientation - Is the case designed to stand up under a desk or to lie flat on a desk? Generally a computer case designed horizontally is called a desktop and a computer case deigned vertically is called a tower.

This orientation can make a difference when designing a workstation environment.

 

Capacity

  • Bays
  • Half height = 1.5 inches high
  • Width 4 or 6 inches
  • Visible and hidden

 

Tower Capacity – Mini (~3) / Mid (~7) / Full tower (up)

 

Form factor - a component's physical shape, size and layout. Geography.

Will your case support different motherboard form factors (XT, AT, ATX, NLX, or LPX)?

 

MOBO/Case form factor issues

  • Size
  • Mounting points
  • Power supply and power connections
  • I/O panel and connections

 

Miscellaneous Case Stuff

Standoffs and studs

 

Slot covers Very A+

  • Create proper "pressure" within system – keeps the system cool
  • Keep things inside of case – EMI
  • Keep things out of case – dirt etc.
  • Use pressurized air (A+)
  • Use small brush (A+)
  • Use special anti-static vacuums (A+)
  • Use dishwasher (not A+)

Other Issues

  • Older cases (pre ATX) you need to hook up power switch
  • ATX uses "soft power" - Very A+
  • Knockouts
  • Hook up front panel connectors
  • Reset switch - 2 pin
  • HDD LED
  • Speaker - 4 pin
  • Power LED - 3 pin
  • Key lock
  • Turbo Switch - not used anymore

 

Hook up power to MOBO - Very A+

  • AT - P8 & P9. Keep the black wires together.

  • ATX is a no-brainer (i.e. keyed). P1. Note that ATX also adds a 3.3v (orange) power source to the 5v & 12v.

 
Note that P4s require up to two extra power sources…

 

  • A power supply is an FRU - Very A+
    • Unplug all connections
    • Remove screws
    • Remove PSU

 

OK, NOW ON TO THE MOTHERBOARD

The large circuit board into which peripheral cards may plug. The motherboard also holds the CPU, RAM, system BIOS and chipset. Components of the MOBO are connected by the system Busses.

After choosing the perfect CPU for your system you are going to need someplace to put it. Choosing a motherboard is one of the most critical decisions you must make when configuring a PC. The components on the motherboard help the CPU achieve it's full potential.

So what’s on it? Learn to ID the major components.

RAM slots

SIMM – usually light tan
DIMM – usually black
RIMM – usually black

Expansion slots

16-bit ISA – usually black
PCI – usually light tan
AGP – usually brown
AMR and CNR cards – usually brown

BIOS

May be rectangular or square
Some people have a manufacturer preference

CPU slot / socket

May support multiple CPUs
Usually only supports one form factor of CPU

ICs for any additional features

RAID
SCSI
Sound
Video
Modem
Network

IO ports

Hard drive / CDROM
Floppy
Serial
Parallel
USB
Firewire
Audio
Video
Network
USB

Front panel connection points

Power
HD LED
Reset
Suspend
Speaker

Other

Battery
Power connection

Chipset


The chipset really controls the system and its capabilities - it is a motherboard manager. It is the hub of all data transfer. It is a series of chips on the motherboard, usually identified as the largest chips on the board with the exception of the CPU.



Chipsets are integrated, meaning they are soldered onto the board and are not upgradeable without buying a whole new motherboard. Intel, VIA, SiS, ALI.

 

A chipset integrates many functions into fewer chips.

Chipsets support specific CPU, memory and bus technologies

 

Usually 2 chips in a chipset

Memory Controller – Northbridge (AGP and memory)
PCI to ISA Bridge – Southbridge (other stuff…)

 

Other MOBO issues

Who made it?

This question is valid for all computer components. When dealing with high technology, quality and customer service should play a big part. What is their reputation? Do they offer a warranty?

There are literally 100’s of motherboard manufacturers.

Manufacturer information may appear at the bottom left of your screen after power on - BIOS ID string. If this information is not displayed, software programs might be able to read it – SISOFT SANDRA.

http://www.motherboards.org

Motherboard Form Factor - Very A+

There are two basic types used today – AT and ATX. The ATX is more recent type. There is no performance enhancement in either, however ATX has a better layout. They are shaped differently so this will affect the type of case to get.
Optional Area
Extended ATX: 12'' x 13'' (304.8 mm x 330.2 mm)
 
Micro ATX: 9.6'' x 9.6'' (234.8 mm x 234.8 mm)
ATX: 12'' x 9.6'' (304.8 mm x 243.8 mm)
Flex ATX: 9'' x 7.5'' (228.6 mm x 190.5 mm)
 
 
Wide I/O Shield - 6.25'' (158.8 mm)

Power supply "fittings" and I/O port locations are different between form factors.

  • XT – very old computers
    • P8-P9 power
    • I/O on expansion cards
    • Ports on the expansion cards
  • AT and baby AT 8.6" x 8.5" MOBOs – medium old computers
    • P8-P9 power
    • I/O on MOBO
    • Ports on dongles
  • ATX – modern computers
    • P1 power
    • I/O on mobo
    • Ports integrated into back of MOBO







Low-profile forms like LPX and NLX or motherboards with "PCI riser cards" are to be avoided.

Edited (2003) By Vlad Magero