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expansion slot

By harleyy75110 ·
What is the purpose of an expansion slot on system board?

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expansion slot

by maxwell edison In reply to expansion slot

I/O Bus Slots:

All motherboards have one or more system I/O buses that are used to expand the computer's capabilities. The slots in the back of the machine are where expansion cards are placed (like your video card, sound card, network card, etc.). These slots allow you to expand the capabilities of your machine in many different ways, and the proliferation of both general purpose and very specific expansion cards is part of the success story of the PC platform.

Most PCs have two different types of bus slots. The first is the standard ISA (Industry Standard Architecture) slot; most PCs have 1,2 or 3 of these. These slots have two connected sections and start about a half-inch from the back of the motherboard, extending to around its middle. This is the oldest (and slowest) bus type and is used for cards that don't require a lot of speed: for example, sound cards and modems. Older systems (generally made well before 1990) may have ISA slots with only a single connector piece on each; these are 8-bit ISA slots and will (of course) only support 8-bit ISA cards.

Pentium systems also have PCI (Peripheral Component Interconnect) bus slots, usually 4, 5 or 6. They are distinguished from ISA slots in two ways. First, they are shorter, and second, they are offset from the back edge of the motherboard by about an inch. PCI is a high-speed bus used for devices like video cards, hard disk controllers, and high-speed network cards.

Newer PCI motherboards have the connectors for the hard disks coming directly from the motherboard. These connectors are part of the PCI bus, even though the hard disks aren't connected to a physical PCI slot.

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expansion slot

by maxwell edison In reply to expansion slot

The newest PCs add another, new connector to the motherboard: an Accelerated Graphics Port slot. AGP is not really a bus, but is a single-device port used for high-performance graphics. The AGP slot looks similar to a PCI slot, except that it is offset further from the back edge of the motherboard.

Older 486 systems use VESA Local Bus, or VLB slots instead of PCI to connect high-speed devices. This is an older bus which began to be abandoned in favor of PCI at around the time the Pentium was introduced. VLB slots look like ISA slots, only they add third and fourth sections beyond the first two. This makes their connectors very long, and for that reason VLB cards are notoriously difficult to insert into or remove from the motherboard.

Some motherboards incorporate a so-called "shared" ISA and PCI slot. This name implies a single slot that can take either type of card, but that isn't possible because the two slot types are physically incompatible. In order to save space while maximizing the number of expansion slots, some designers put an ISA slot on the board right next to a PCI slot; you then have the choice to use either the ISA or the PCI slot, but not both. This design is possible because ISA cards mount on the left-hand side of a slot position, while PCI slots mount on the right-hand side.

More information on system buses can be found here.

http://www.pcguide.com/ref/mbsys/buses/index.htm

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expansion slot

by harleyy75110 In reply to expansion slot

The question was auto-closed by TechRepublic

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expansion slot

by opatzg In reply to expansion slot

The reason to have expansion slots on your motherboard is to allow you to upgrade your system with new and improved features. Normally the video/sound/modem/network cards which fit into the expansion slots work better with software than those whichcome built onto the motherboard. They're normally newer/ faster/ and more the industry standard to which software developers write there programs for. It's kind of like if you aren't using a soundblaster sound card for the sound with video gaming you're almost guaranteed incompatibility problems. Expansion slots let you add these cards to your system.

With that said an AGP slot is for the best current video upgrade cards out there. It is brown and located closest to the center of the board with pci slots to the side of it if your board has one. For a good look go to tigerdirect and enlarge the image on some of there boards. The newer boardss you're looking at will only be PCI with one AGP. The other smaller connectors are for modem cards and sound cards which I have not seen. I beleive they're called amr and c something slots.
Hope that answers your question.
The white PCI slots are for most any newer board/card since around 1995.
And the short and long ISA brown slots with large 1/8 inch copper connectors in the slot are for older machines and cards which come in 8 bit and 16 bit connections

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expansion slot

by harleyy75110 In reply to expansion slot

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by harleyy75110 In reply to expansion slot

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