• Expansion Slots Define
• Computer Expansion Slots Types
• Purpose Of Expansion Slots And Adapter Cards
• Expansion Slots Definition Computer
• Purpose Of Expansion Slots

Nintendo's Expansion Ports

by Danny Bivens and Aaron Kaluszka - October 26, 2011, 11:19 am EDT
Total comments: 52

What's the deal with those expansion ports on Nintendo's older systems?

In a day and age where USB ports are prevalent on our game systems, expansion ports on video game consoles definitely harken to a gaming yesteryear that players can only look back on in awe. What once used to be a staple on many console releases is now a thing of the past.

In previous Nintendo consoles, these expansion ports were portals to improve hardware, open up new possibilities for gameplay, and even to give the hardware additional features that were just not possible with the original release. Now we look back on past Nintendo hardware and not only examine how Nintendo used these mysterious ports, but also the kinds of devices that utilized them. From this, we have a picture of the company's past as well as some insight on where Nintendo are taking their hardware in the future.

An expansion bus is an assortment of wires that allows for computer expansion with the use of an expansion board, a printed circuit board inserted into an expansion slot on the motherboard or backplane that provides additional features to a computer system. Answer:An expansion slot is a socket on the motherboard that is used to insert an expansion card (or circuit board), which provides additional features to a computer such as video, sound, advanced graphics, Ethernet or memory.Expansion cards can provide various functions including: 1. Interface adapters 5. An expansion slot refers to any of the slots on a motherboard that can hold an expansion card to expand the computer's functionality, like a video card, network card, or sound card. The expansion card is plugged directly into the expansion port so that the motherboard has direct access to the hardware.

First up is the Famicom and NES. Unlike the NES, the Famicom came with hard-wired controllers. Any extra controllers and peripherals could be plugged into Nintendo's first expansion port, which was located at the front of the machine. This port was used to host light guns, 3D shutter glasses, keyboards, extra controllers, and other items. Many system expansions plugged directly into the cartridge slot, such as the Famicom Disk System and the Famicom Modem. The Sharp Twin Famicom, a system that combined the Famicom and Disk System into one machine, added an additional three expansion ports, but these remained unused.

The NES shipped with an expansion port on the bottom of the console. On multiple occasions, modems were planned to be connected there. However, the NES expansion port never received a commercial application. Originally, the port was covered by a snap-in cover, but later model systems actually had a plastic tab covering the port completely. The port was still there, but the plastic actually had to broken off to access the port. The lack of expansion port utilization outside of Japan was an ongoing trend that started with Nintendo's first system.

The Super Famicom takes us on a story of CD drives and further connectivity. Like the NES, the Super Famicom and SNES designed included an expansion port marked EXT. The well-known SNES CD would have used this port, and the Satellaview did make use of it, but only in Japan. The SNES did see a very limited use of the port as a connection point for the Exertainment exercise bike.

The Nintendo 64 brought us the Expansion Pak and the Disk Drive, one for each port. Continuing the trend, the EXT port, which resides on the bottom of the N64, would only be used in Japan for the N64DD, which was cancelled early and never saw a worldwide release. The memory expansion port on the top was necessary for certain games that needed the extra power, and this saw worldwide use.

The GameCube upped the number of expansion possibilities to three. Featuring two serial ports and a hi-speed port, the GameCube had the most expansion possibilities, though one serial port remained unused. The options were limited, but this time, all expansions were released worldwide. The Hi-Speed port was home to the Game Boy Player attachment, while the larger serial port could house a modem or LAN adapter.

With the advent of the Wii, Nintendo decided to standardize their hardware connections, including two USB ports and an SD card slot. The Wii U includes the same interfaces, indicating a likely end of Nintendo's mysterious ports.

Next, we take an in-depth look at all of the system expansions. We will cover one system each day.

Photos provided by Danny Bivens, James Charlton, Nicholas Bray, Minoru Yamaizumi, Aaron Kaluszka, Uncle Bob, and 64DDFan

Talkback

I believe it was so Nintendo could change/add any extra code to the motherboard/processor. That's probably why they were never needed after launch of the console. It was just easier for development and all that.
That's just my thought.

I believe it was so Nintendo could change/add any extra code to the motherboard/processor. That's probably why they were never needed after launch of the console. It was just easier for development and all that.
That's just my thought.

Then why would they include it in the production model and not just the dev kits?

I believe it was so Nintendo could change/add any extra code to the motherboard/processor. That's probably why they were never needed after launch of the console. It was just easier for development and all that.
That's just my thought.

Then why would they include it in the production model and not just the dev kits?

I'm not a game dev but wouldn't it make sense to have the production model also be the Dev Kit with just an addon that plugged into the special slot?

Shame that the test model SNES apparently hung out with a couple of smokers.

It's not caused by smoking. There's an interesting article about the science of the yellowing here and how to fix it here.

Strangely my Super Famicom is fine but my Famicom is a disgusting yellow colour! (as you can see from my photos above)
More on topic though, I would have loved to have been in Japan during the disk system days, getting to use the disk writer in a shop etc!
I'm too afraid to get a Disk System now though, knowing how unreliable they are.
The next part of the feature, SNES/SFC, is a really interesting part of history.

This is a wonderful article, I really think a podcast would serve it justice . Most of the expansions should have been built in to begin with, and nintendo KNEW they should have but didn't.

The NES Top Loader and SNES-mini both removed the expansion ports... Oddly, though, the redesigned N64 (i.e.: The Pikachu edition) actually included the expansion port... but there was no removable cover - the port is inaccessible without actually removing the bottom half of the casing.
I've heard there are revised GameCubes floating around out there that are missing the second serial port, but I've never seen one (never really spent a lot of time looking though).

I've heard there are revised GameCubes floating around out there that are missing the second serial port, but I've never seen one (never really spent a lot of time looking though).

But you must add one to your collection. How does it not bother you that you do not own one of these mythical revised Gamecubes? It's like I don't know you anymore.
...

But you must add one to your collection. How does it not bother you that you do not own one of these mythical revised Gamecubes? It's like I don't know you anymore.

You'd think that - but, out of the 7 Game Cubes I own, 6 are original -001 units and one's the Panasonic Q. I don't even own a -101 unit. ;)

Found a neat site that shows all three hardware revisions of the GameCube...
http://www.classiccmp.org/dunfield/vg/nintendo.htm
The GCN went through three revisions, although only one really changed the bottom ports. A semi-educated guess would be that the second revision is limited to the 'Limited Edition' Platinum consoles. As I don't have any Platinum GCNs (not counting the Q, of course) or any -101 units, that would explain why I haven't come across one. I'll have to be on the look-out now. :D

There should be a similar thread made for all of Nintendo's controlles and peripherals.

Found a neat site that shows all three hardware revisions of the GameCube...
http://www.classiccmp.org/dunfield/vg/nintendo.htm
The GCN went through three revisions, although only one really changed the bottom ports. A semi-educated guess would be that the second revision is limited to the 'Limited Edition' Platinum consoles. As I don't have any Platinum GCNs (not counting the Q, of course) or any -101 units, that would explain why I haven't come across one. I'll have to be on the look-out now. :D

Nice link.
I have a platinum console with the digital outs - apparently pretty rare. A friend was convinced they didn't even exist until seeing mine. Pretty lucky I guess, since it was picked up second-hand from EB Games as a backup system for the GameCube titles that I purchased after owning a Wii.
Oddly, tracking down an official component cable for the system was MUCH more expensive than the console itself.

Oddly, tracking down an official component cable for the system was MUCH more expensive than the console itself.

Don't look at my five sets then. :D Four of which I scored from GameStop for under $5. :D
But to your other point, I think the only Platinum systems with the Digital Out are the original releases that were marked 'Limited Edition' - it's my guess (without any hardcore evidence) that when the Platinum system became standard was when they removed the Digital Port (and revised the base). Could likely be wrong though.

My Component cable for the GCN was ordered directly from Nintendo and I probably posted about it here somewhere. It was Night and day. When the component cables for Wii became first available through Nintendo I ordered a set of those because I didn't want a repeat of the GCN. Though I have adapter to connect my GCN to everything in US but DVI and HDMI (VGA, Coax, Component, RCA, S-Video, etc.)

Oddly, tracking down an official component cable for the system was MUCH more expensive than the console itself.

Don't look at my five sets then. :D Four of which I scored from GameStop for under $5. :D
...

I'm not disappointed. Mine were well under the going price - it's only when you compare them to paying $10 for the entire console that it feels expensive.
If you are lucky, you can still score GameCube component cables at GameStop for cheap. Where you live plays a huge part in that though.
http://www.gamestop.com/accessories/gamecube-n64-component-cable-used/32149?utm_source=linkshare&utm_medium=affiliate&utm_campaign=deeplink&cid=afl_10000087&affID=77777&sourceID=FKSJxY2VJAk-YdQjxU0sI4sci3bux6kWNg
Of course, some hits are false-positives and sometimes you get lucky finding mislabeled cables where there aren't supposed to be any. A great deal if you stumble into any though!

I've thought about getting component cables for my GC to cut out the input lag when I do recordings of Game Boy Player for my YouTube channel (I actually own a component video capture device). Generally, I've seen these things sell for $60-$100 on eBay. By the way, did you notice the component port is labeled 'Digital Out' even though component is analog?
I do own an official Nintendo SNES S-Video connector (bought for my N64 after we got a new TV with said inputs).

Its a shame the port on the NES was never used. Does anyone know if it would be possible for some hobbyist or whatever to create peripherals for that port somehow? It was supposed to be used for a modem but Nintendo never created that modem, but could someone else make it happen? All the patents regarding the NES have expired since 2005 so there is no legal obstacles to people doing stuff like that, but are there technical obstacles?

By the way, did you notice the component port is labeled 'Digital Out' even though component is analog?

Actually... the port is 100% correctly labeled. The port actually does send out a digital signal.
*Most* electronics convert that digital signal to analog inside the system, before it gets to the port.
With the GameCube, it actually sent the digital signal to the port - the Digital-to-Analog conversion was done in the Component Cables themselves - this is why the cables were so expensive new and why you've never seen an off-brand/third party set of GameCube cables that output component signal.

It's also what let people mod them into awesome VGA cables. The Wii was truly a downgrade in that sense.

I think the only Platinum systems with the Digital Out are the original releases that were marked 'Limited Edition' - it's my guess (without any hardcore evidence) that when the Platinum system became standard was when they removed the Digital Port (and revised the base). Could likely be wrong though.

Well, I don't really have anything for/against the 'Limited Edition' Platinum 'Cubes all being with the Digital Out port while the non-Limited Edition 'Cubes are without, but...
I stopped into a Goodwill today - they had a Platinum -001 GameCube... No cords and $10 price tag (I passed) - but I did take a second to look it over. it was a -001, but it did have the third port on the bottom.

You didn't mention any of the problems with the N64 RAM expansion pack. For instance it pretty much broke Space Station Silicon Valley.

I've read many times that Game Boy Player is kinda laggy. Is this true?

I never experienced any lag with my Game Boy Player.

I've read many times that Game Boy Player is kinda laggy. Is this true?

I've only had one such experience... kinda.
Back in the day, when I was running a solo-GameCube, a friend brought his over along with his Game Boy Player. We hooked them up and played some Four Swords (GBA) on the big screen. It was awesome.
Anyway, during one round, we came 'desynched' - the Links on both screens would still respond to their respective controls, but they weren't in the same spot... so I could be walking up a path on my screen and be walking into a wall on his screen. Likewise, he could pick me up on his screen and I'd be running around like nothing was wrong on mine.
The /official/ word from Nintendo is that you're not supposed to link Game Boy Players together... but I've done it many times and this is the *only* time I've ever had a problem with the Game Boy Player - in any fashion.

Oh wow, Warp Pipe and the LAN adapter. Never got a version of Warp Pipe to work right... something about the lappy I was using at the time... so long ago.
Never could get into PSO. Played it a few times but it seemed to mostly be people standing around chatting. No thanks. Plus it was a SEGA game and SEGA games *suck*! ;D

Now that internet speeds are faster, we should try to get a Double Dash Warp Pipe tournament going.

Now that internet speeds are faster, we should try to get a Double Dash Warp Pipe tournament going.

Totally up for trying that sometime. Lord knows it went... poorly the last time I tried.
I don't know about a 'tournament' though - we'll be lucky to get two people connected. ;)

It'd be cool if someone had come up with a Homebrew Channel hack that lets GameCube games see the Wii's Wi-Fi as a broadband adaptor. I'd imagine that would up the numbers we could pull in for such an event.

If by 'come up with a hack,' you mean 'write an operating system...'

If by 'come up with a hack,' you mean 'write an operating system...'

For those who dabble in such things, does anyone know if the GameCube emulator for the PC does LAN Modes on compatible games? And not Online where the second player is the second controller - but actually supportive of the LAN modes built into the games?
Would it be possible to write a GCN emulator for the Wii? Is the Wii actually powerful enough for such a thing?

Fun Fact: Since we're kind of on the subject.
For those who have never seen it, in Mario Kart: Double Dash, the LAN Mode is a selection on the main menu screen - it only appears of you have a LAN Adapter in your GameCube.
What's really fun though - the Demo Disc (the ones for the in-store demo units) that contains a Mario Kart: Double Dash preview... the LAN Option shows up on that menu - again, only if you have a LAN Adapter installed... but you can't select it at all. Just kinda neat.

Would it be possible to write a GCN emulator for the Wii? Is the Wii actually powerful enough for such a thing?

No, at 1.5x specs of the GC, the Wii is far too weak to emulate the GC (a rule of thumb used to be that you'd need at least 10x power, and that would be with speed hacks). Instead, you'd need to rewrite the GC BIOS to take into account the additional hardware and emulate the LAN adapter. However, that additional hardware part is non-trivial because you'd have to write drivers for the Wii security and I/O systems, which the GC BIOS doesn't know exist. Going in the other direction, you might be able to run the GC game as Wii software, with hooks patched in memory to deal with the network and any Wii-isms. In either case, it would involve massive architecting that would be hard even if all of the technical information was publicly available.

No, at 1.5x specs of the GC,

Didn't Iwata or someone else at Nintendo say the Wii was 2 to 3 times more powerful than the GC?

It doesn't matter what they said. The Wii CPU and GPUs are clocked at 1.5x the GC, and the memory was roughly doubled (it's more complicated than that).

wonder hiw many times more powerful the Wii U will be over the Wii?

well considering I think someone said next E3 you'll see the more final design of the Wii U, I hope it has an expansion port, so it is future proofed. I had forgot about the GameCube's port, and that I actually used it for the GBA player. The Wii was future proofed as well in the controllers, but not the system itself.

The Wii U has USB ports, which is the modern version of expansion ports (unfortunately, Nintendo didn't do much with them on the Wii).

I learnt a lot from this feature, very interesting stuff here!
I'm especially into the SNES and N64 stuff, gotta love those add-ons!
Big thanks to Danny for digging up all this info and putting all in an easy to read manner, makes life easy for lazy people like me! ;D

We should really try a Warp Pipe Mario Kart match up. Who's in?

We should really try a Warp Pipe Mario Kart match up. Who's in?

Maybe if I can find all my stuff.

Oh wow, Warp Pipe and the LAN adapter. Never got a version of Warp Pipe to work right... something about the lappy I was using at the time... so long ago.
Never could get into PSO. Played it a few times but it seemed to mostly be people standing around chatting. No thanks. Plus it was a SEGA game and SEGA games *suck*! ;D

That annoyed me about PSO. When you found a group that wanted to play the game then it was great. I'm glad the Monster Hunter Community isn't super chatty like the PSO one was.

The Wii U has USB ports, which is the modern version of expansion ports (unfortunately, Nintendo didn't do much with them on the Wii).

But you can't add more RAM to a system via a USB port, can you? Yet the N64 had an expansion port which allowed just that, and Nintendo released the RAM pack so it actually happened. It might not be a bad idea for Nintendo to include a port in the Wii U to allow the RAM to be expanded at some future point so that it can remain competitive against the PS4/420.
If that can be done via a USB port, then fine, but everything I know or think I know about USB leads me to believe it isn't really capable of that so some other sort of port is required.

If the Wii U had a a spot for an internal HDD then it it would be the modern day equivalnet of the N64 memory expansion pack and port.

If the Wii U had a a spot for an internal HDD then it it would be the modern day equivalnet of the N64 memory expansion pack and port.

Wrong kind of memory expansion.

What BnM said.
But I would also like to see a port or slot or drive bay or whatever you call it for an internal HDD to be added if the user so desires. I understand if Nintendo doesn't want to bundle a $50 HDD in the system by default in order to cut costs, but it would be nice if the option existed for users to add one in themselves. The PS2 was that way, so its not like that is unprecedented.
But yes, that is separate from the RAM which would be nice if that could also be upgraded later on.

Ram can't be added vi any cost effective standard connector, I think Infiniband and like is fast enough.
I have mixed feelings about RAM upgrades in consoles. Harddrive style space is sort of a non-issue but, RAM starts diversifying the spec and makes moving targets for developers.

Any game which would require a RAM upgrade could come bundled with the RAM upgrade. That's how it was with the N64 games which required the RAM Pak. I'm not sure how much a RAM module would cost, but hopefully it could be manageable.

Any game which would require a RAM upgrade could come bundled with the RAM upgrade. That's how it was with the N64 games which required the RAM Pak. I'm not sure how much a RAM module would cost, but hopefully it could be manageable.

That's partially it. I mean Capcom is citing a slightly bigger cart for RE:Rev as the $10 premium reason. Which is bull but, think if you had to pack in something else. Not to mention if its popular we as gamers have 10 or so of them. Not good for the environment.
In theory that's great but in Practice its Wii Motion+.

Nothing wrong with Wii Motion+. Even if Zelda Skyward Sword alone were the only game to support it that would make it a success in and of itself. Wasn't Zelda one of the games on the N64 which required the RAM Pak? Considering the N64 Zelda games were top notch and regularly top the lists of the greatest games of all time, I'd say that makes the N64 RAM Pak a success even if absolutely no other game ever supported it.

Didn't Sega teach us that add-ons are a bad idea, partly because they split the userbase? Adding anything significant to a system halfway through its market cycle just isn't a good idea. The N64 Expansion Pak and Wii Motion Plus are essentially just accessories, since only a handful of games actually require them. The Kinect and PSMove are a little more successful, but still aren't the new standard for those systems and haven't really gotten out of accessory status.
The only exception I can think of is the PlayStation's Dual Analogue and then Dual Shock controllers, but they were added before the system gained significant market share. There were also still few games that required them, so for people who bought one of the first systems they were not a necessity. This is also why the 3DS slide pad add-on may also work out, since it's happening early on and likely won't be required for just about everything.

Didn't Sega teach us that add-ons are a bad idea,

The way Sega did it was bad. The problem wasn't the addon itself or the idea, it was that it conflicted with the Saturn and competed with it which split Sega's resources and pissed off fans and developers alike. It should have either been the Neptune or the Saturn, but Sega released both and that was the problem. If it was just one or the other I think things would have turned out very differently.

The motherboard is the main system board for the computer and connects all of the internal hardware components. This lesson will take a look at various components which are built into the motherboard. This lesson will also look at the expansion slots used to add hardware components to a system. The lesson finishes up with a discussion of the BIOS.

Lesson Objectives

By the end of this lesson, you will be able to:

1. Identify the components on a motherboard.
2. Identify the function of the Northbridge.
3. Identify the function of the Southbridge.
4. Recommend a motherboard for a given scenario.
5. Identify appropriate BIOS settings.
6. Differentiate expansion slots on the motherboard.

Instruction

A computer technician must have a strong understanding of the components used within a computer system. Understanding the purpose of each component provides the foundation of knowledge required to understand the operation of a computer system.

Motherboards

The motherboard is the largest printed circuit board, and every electronic device has one including computers, cell phones, printers, cars, and even toasters.

The motherboard determines the capabilities and limitations of a computer system. Every component on a computer system plugs into the motherboard is controlled by it and depends on it to communicate. The motherboard houses the following components:

• Central Processing Unit (CPU) – performs all basic arithmetic, logical, control, and input/output operations
• Chipset – manages the data flow between the computer’s processor, its memory and any peripheral devices attached
• Buses – a pathway that transfers data between components within a computer
• Random Access Memory (RAM) – a temporary form of computer data storage that allows fast access to data. RAM is volatile and requires power to keep data accessible.
• Expansion slots – provide expansion capability to add hardware components beyond what was originally installed
• Ports – provides an interface between the computer and a peripheral device such as a mouse, keyboard, or printer

All of the above components are labeled in Figure 1.

Figure 1: Motherboard Diagram with all components labeled

There are several components that comprise a motherboard. In this lesson, the following main components will be highlighted:

1. System Clock
2. Chipset
3. Expansion Cards and Slots
4. Front Panel Connectors
5. Basic Input/Output System (BIOS)
6. Complementary metal–oxide–semiconductor(CMOS)
7. System bus with expansion slots
8. Bus Structures

System Clock

Think of the system clock as the heartbeat of the motherboard. It sets the speed of all other components like the processor, memory, and buses. It has a base speed that is measured in hertz (Hz), but computers run in megahertz (MHz) or gigahertz (GHz).

Chipset

The chipset determines how system hardware and buses interact with the CPU and other components. It also determines how much memory can be added to a motherboard and what type of connectors the motherboard will have.

Current chipsets are made up of two distinct components – the Northbridge (NB) and Southbridge (SB).

The Northbridge controls RAM, the processor, and the Accelerated Graphics Port (AGP) video slot. It also regulates the speed the CPU can communicate with the components.

The Southbridge controls everything else connected to the computer including communication between the CPU and the expansion ports (hard drives, sound card, Universal Serial Bus (USB) ports, and other I/O ports).

Figure 2: Components of a chipset

The Northbridge (labeled NB) and Southbridge (labeled SB) are both shown on a laptop motherboard in Figure 2.

Expansion Slots

Expansion slots allow the installation of extra components. Peripheral Component Interconnect (PCI), are used to install network cards, sound cards or modems.

AGP slots accommodate video cards with additional capabilities and PCI express (PCIe) cards to connect host bus adapters (HBAs) for expanded storage and cards for additional USB and Firewire ports.

Expansion Slots Define

Figure 3: Expansion slots on a motherboard

Riser Cards

A riser card physically extends a slot so multiple cards can be plugged into a motherboard. The expansion cards will actually be turned 90 degrees to the motherboard. This allows cards to fit into a smaller space. Riser cards are usually only used in low-profile or slimline cases.

Figure 4: Multiple slot riser

The one slot on the motherboard can now accommodate multiple expansion cards.

Figure 5: Multiple slot riser seated in a motherboard

Other Slots

Other slots encountered on the motherboard include the audio/modem riser (AMR) and the communications and networking riser (CNR). These two slots do basically the same thing with the CNR having a few additional functions. They were created to hold modems, network cards, and sound cards. You will seldom see these used on today’s motherboards.

As shown in Figure 6, the 30-pin AMR slot is much smaller than a PCI expansion slot. The 30-pin interfaces accommodate two formats making various audio/modem and audio network combinations possible.

Figure 6: Audio/Modem Riser (AMR) slot next to white PCI slot

The AMR evolved into the CNR adding LAN and home networking functions.

Figure 7: Communications and networking riser (CNR) slot

Front Panel Connectors

Front panel connectors are used to connect the power LED (light emitting diode) light on the front of the case to a hard drive, a small internal speaker for testing, the power button, and the reset button. There may also be additional LED lights for USB, Firewire and audio devices.

All of the front panel connectors from the case get plugged into tiny pins on the motherboard. The layout of the pins varies from motherboard to motherboard, although they are usually grouped together and color-coded. You may or may not use all of the connectors.

Sometimes the power LED has a blank pin between the two wires. You can buy an adapter to change the pin layout or simply cut the connector to accommodate the pins.

It is important to note that the reset jumper must be attached to the pins, in the correct order, before the computer will start. If nothing happens when you turn on the computer for the first time, check that the reset jumper was attached correctly.

You may view a visual installation of connectors to the pins on a motherboard at the following URLs:

1. MSI HOW-TO Install front panel connectors (JFP1) (1:09)
2. Instalacion del Panel Frontal (3:46)

It is important to remember that each motherboard is different, and it is important to look up the proper connections in the motherboard manual.

Figure 8: Connection schematic using a sample motherboard front panel connector

BIOS – Basic Input/ Output System

The Basic Input/ Output System (BIOS) may be referred to as the System BIOS or ROM (Read Only Memory) BIOS. The BIOS holds the motherboard’s firmware which is nothing more than a set of instructions. It is the first software run when the computer is powered on.

The fundamental purpose of the BIOS is to initialize and test the system’s hardware components and to load the operating system. The BIOS provides a consistent way for applications and the operating system to interact with I/O devices like the keyboard, mouse, display, and other connected devices.

BIOS and CMOS

Working with the BIOS is a chip known as the complementary metal–oxide semiconductor (CMOS). The CMOS holds the settings you selected in the BIOS. CMOS is volatile in nature. That means it must be supplied with continuous power that is supplied by a battery. If the battery runs down settings will be lost.

Figure 9: CMOS Battery

The BIOS has a menu-based user interface to make changes such as:

• Configure hardware
• Make changes to I/O ports
• Set the system time
• Enable or disable system components
• Set voltages for the CPU and memory
• Set the boot sequence
• Control fan speeds
• Set a BIOS and system password
• Enable or disable virtualization support

Users can set various password prompts, such as a password for securing access to the BIOS user interface functions itself and preventing malicious users from booting the system from unauthorized peripheral devices.

Figure 10: Phoenix BIOS chip

BIOS Options

The first thing the computer does when it is turned on is to run a diagnostic program called the Power on Self-Test or POST. The POST checks that all the motherboard components are functioning and can communicate with each other.

The BIOS can be accessed at system startup with a particular key sequence. This is usually the delete key or the F2 key, but different manufacturers may have a different sequence to press.

Figure 11: CMOS Setup Utility

Built-in tools can monitor the following:

• • Temperature
  • Fan Speeds
  • Intrusion detection
  • Voltages
  • Clock
  • Bus speeds

To see additional screenshots of various options that can be viewed and/or changed in the BIOS setup, browse to MSI 790GX-G65 Motherboard Reviews and scroll down to the bottom of the page.

The BIOS software is stored on a non-volatile ROM chip on the motherboard. This means the chip does not lose its contents even if there is no power going to the BIOS.

Using the BIOS menu, you are able to change hardware configurations such as the order in which the PC boots – floppy drive, hard drive, CD-ROM, USB.

The ROM BIOS is commonly called the computer’s firmware. Firmware used to be hardcoded on the chip and could not be changed without replacing the chip. Most modern devices can be upgraded when new features are added. This process is called flashing the BIOS.

Newer BIOS chips are made of Electrically Erasable Programmable Read Only Memory (EEPROM) chips. This type of chip allows the content of the BIOS to be rewritten without removing the chip from the motherboard. This way the BIOS software can be easily upgraded to add new features or fix bugs.

So what happens if you set a BIOS password and then forget what it was? The BIOS and system passwords can be easily erased along with all the other user settings. This can be done by removing the battery, waiting a few seconds and then putting it back in.

The most common way is to locate the CMOS reset jumper. Simply move the jumper to the enabled position (jumper on pins 2 and 3), and turn on the computer which sends an electrical signal to erase the CMOS. Be sure to then move the jumper back to the disabled or default position (jumper on pins 1 and 2). The CMOS is now back to the factory default settings.

Figure 12: CMOS Reset jumpers

EFI and UEFI

Starting in 2011, the BIOS was replaced on some motherboards with a more complex Extensible Firmware Interface (EFI) or the Unified Extensible Firmware Interface (UEFI). This new BIOS type was introduced to provide more diagnostic and repair tools to the computer and provide a more efficient interface between the operating system and the components.

Initially made for the Itanium architecture, it is now available for x86 and x64 platforms and provides legacy support for BIOS services. It can support remote diagnostics and repair of computers, even without an operating system

Figure 13: Extensible Firmware Interface (EFI)

Computer Expansion Slots Types

Documentation

It is very important to document the settings you have changed in the CMOS. This way if something ever happens, like the CMOS battery runs down, you have a record of what the previous settings were and how to reset them.

It is recommended that you tape your documentation inside the case so anyone that works on that computer has a copy of your configuration.

Keep well-labeled, written record of:

• All changes you make to CMOS
• Records of hardware and software installed
• Network settings

Keep documentation up to date and in a safe place. Also, the document before you flash or replace the BIOS chip.

Bus Structures

A bus can be defined as a channel or path between components. The speed of the bus has a lot to do with the speed of the computer.

There are a lot of incredibly complex components in a computer, and all of these parts need to communicate with each other in a fast and efficient manner. Otherwise, the amazing speed and capabilities of each individual component is lost in the whole.

Purpose Of Expansion Slots And Adapter Cards

Typical Bus Structures

There are two key buses in a computer: the system bus and the shared bus.

The system bus is also called the local bus or front side bus. This bus connects the CPU to the system memory. It is one of the most important buses in the system. The faster the processors can move information in and out of the memory, the faster computers operate. When selecting a motherboard, find one with the fastest system bus possible.

The shared bus is what connects all the other components to our computer and moves information around inside the motherboard.

The shared bus connects the Industry Standard Architecture (ISA), Extended Industry Standard Architecture (EISA), PCI, and PCIe, USB, and Firewire buses together. This is done through bridges, which are part of the computer’s chipset. This bridge acts as a traffic cop, integrating the data from the other buses into the system bus. This bridge lets multiple devices access the same path to the CPU and system memory.

Expansion Slots Definition Computer

Most chipsets have two bridges: the Northbridge and the Southbridge. You can see in Figure 13 that the Northbridge controls the CPU, memory, and the AGP slot for video. The front side bus, memory bus, and AGP bus all connect to the Northbridge.

The Southbridge basically controls everything else. Hard drives, CD players, DVD players, PCI bus, and I/O ports are all connected to the Southbridge. The Southbridge regulates what bus and how much information can be passed to the Northbridge.

Figure 14: Bus structure

Summary

The motherboard is considered the nervous system of a computer. Everything that is not built into the motherboard is connected to it in slots or through ports. Its main components are the system clock, CPU, chipset, RAM, ROM BIOS, CMOS, power supply, ports, and the system bus with expansion slots.

Information stored in the BIOS is powered by the CMOS battery. Without the battery, the BIOS settings would have to be reset each time the host is booted. Information, such as the type of hard drive, the boot order, date and time, is stored in BIOS and is used by the host when it is booting.

Purpose Of Expansion Slots