Expansion Slots 

In this video from ITFreeTraining, I will have a look at the different expansion slots inside a computer. Expansions slots allow an adapter card to be installed in a computer, increasing the features of that computer. Knowing which expansion cards are available and what they can do will assist you when upgrading computers.
Download the PDF handout: itfreetraining.com/handouts/ap...
Expansion cards
0:20 Expansion cards have been available for computers ever since the first IBM PC was released. The expansion card simply allows the computer to be expanded, thereby adding additional features. There are many different expansion cards on the market. Shown here is a SATA card. This card provides two additional SATA ports and RAID functionality.
Expansion cards can also be quite small, as you can see in the case of this network card. In order for an expansion card to be put into a computer, the expansion card requires a matching slot. The slots differ in size. For example, in the case of this fibre card it was removed from a dedicated hardware server. For this type of expansion slot, it is possible to have different sized slots with the larger slot sizes generally only found in servers.
Expansion cards can also be very large in size. Many high performing video cards on the market will be quite large like the one shown here. If you are installing a large expansion card, make sure that it will fit into your computer case. I once had to remove part of a computer case with a hacksaw to get a large graphics card to fit into the computer case.
Peripheral Component Interconnect (PCI)
1:30 The first expansion slot that I will look at is the Peripheral Component Interconnect or PCI. There were other expansion slots before this, however you will not be tested on these in the CompTIA exam. PCI was introduced in the early 90’s. PCI essentially attaches devices to the motherboard. PCI can be used to connect to integrated chips on the motherboard or it can form a bridge to the expansion cards. PCI essentially provides a standard for communication between the motherboard and devices which can be implemented in many different ways.
In this case, I will be looking at the expansion slots. The first PCI slot I will look at is the 32-bit 3.3 volt PCI slot. There were a number of different versions of PCI released with the last release being in 2004. Thus, PCI is not a new technology.
You can tell it is a PCI 3.3 volt slot due to the location of a notch on the PCI expansion slot. You will notice that in this example of a PCI card, the notch lines up with the notch in the expansion card. This indicates that the card is a 3.3 volt card.
Nowadays, PCI Express has replaced PCI. I will look at PCI Express later in the video. For this reason, motherboards on the market will have one or maybe two PCI slots, if any at all. You will generally find that if the motherboard has any PCI slots, these will be the 5 volt expansion slots. These expansion slots have a notch further down the expansion slot then on the 3 volt. You can see the example PCI card will have the notch in the same place. This prevents 3 volt cards being put into 5 volt slots.
The slots themselves will only support the one type of card, however a manufacturer can design their card so it will work in both slots. You can see in this example that the PCI card has two notches in the card, thus this expansion card will work in both slot types.
PCI was a big improvement over previous slots and became the dominant slot on motherboards. One of the main reasons was its ability to support plug and play.
PCI and Plug and Play
3:50 The development of PCI started a radical change in how expansion cards worked. PCI allowed for automatic configuration of resources for an expansion card, otherwise known as plug and play. In the early days this was known as plug and pray as it was unreliable, however nowadays plug and play is very reliable and something the technician does not think too much about because it just works. The question remains, what is plug and play?
Description to long for RU-vid. Please see the following link for the rest of the description: itfreetraining.com/ap/1b82
References
“The Official CompTIA A+ Core Study Guide (Exam 220-1001)” Chapter 3 Position 6553-6636, 6828-7999
“CompTIA A+ Certification Tenth Edition” Chapter X Pages 219-223
“Conventional PCI” en.wikipedia.org/wiki/Convent...
“PCI Express” en.wikipedia.org/wiki/PCI_Exp...
“A History of PC Buses - From ISA to PCI Express” • A History of PC Buses ...
“Linux Device Drivers, 3rd Edition” www.oreilly.com/library/view/...
Credits
Trainer: Austin Mason ITFreeTraining.com
Voice Talent: HP Lewis hplewis.com
Quality Assurance: Brett Batson www.pbb-proofreading.uk