Form Factors

In this video from ITFreeTraining, I will look at the different form factors that are available for computers. The form factors determine the design constraints for the motherboard, case and power supply. All three need to conform to the form factor design specification to ensure that they will work together.
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Form Factors
0:18 To start with, I will look at what a form factor is. A form factor defines the dimensions and layouts that can be used for the motherboard, power supply and the computer case. You will find that motherboards designed to meet a form factor specification will be the same size or very close. On closer inspection, you will find the drill holes are in the same place. This ensures that when you buy a motherboard of a particular form factor it will always fit inside a computer case that supports that form factor. The motherboard is attached to the computer case by standoffs. Standoffs are brass or plastic that attach to the computer case and provide somewhere for the screws to screw into.
The form factor also defines the power supply unit and the connectors that are used on the power supply. This is why you will find that different power supplies are the same shape and have the same connectors on them.
The form factor also defines the size of the area that will be used by the input and output connectors otherwise known as IO connectors. The IO area allows the motherboard to be connected to external devices like keyboards, USB devices and speakers. You will find that the area generally has a silver cover called the IO Shield. The area for the IO connectors will always be in the same place and also will always be the same size.
The form factor also defines the specifications for the computer case. The specifications gives the manufactures a lot of creative choices on how they design their case. A computer case may also support one or more form factors.
Having a form factor specification ensures that a motherboard and power supply designed for that form factor can be used in that computer case. As previously mentioned, the form factor will define where the screw holes in the motherboard will be. In order for the computer case to support a specific form factor, it will need to have screw holes in the correct locations.
AT Form Factor
2:22 The first form factor that I will look at is the AT form factor. This form factor was first invented in the 1980s. AT stands for Advanced Technology. At the time, AT was advanced technology. Now days this form factor is obsolete and has been for a long time. It is unlikely you will get asked any questions in the CompTIA exam about it, but it is good to have a basic understanding of how it works. Understanding how the AT form factor was designed helps to understand why modern computers are designed the way they are.
You can see the motherboard has a large number of chips on it. Back in those days, computers were new and it took a lot of chips to achieve what we can now achieve with a single chip. As a result, the AT motherboards were very large compared to motherboards you would find in computers today.
The main drawback of the AT form factor was the limited number of external ports. Generally, on the back of the computer you would have the keyboard port, two serial ports and a parallel port. If you had a mouse, one of the serial ports was used by the mouse. As computers improved, there became more need for additional ports. The original design of the AT form factor did not take into consideration how computers could change over time.
The next main difference is the power supply unit. On AT computers, the fan on the power supply is an intake fan. That is, air is drawn from outside into the computer case. In the old days of computers, the CPU and other components did not get that hot. Due to the low working temperatures, an intake fan was enough to keep the inside of the computer cool.
Description to long for youtube. Please see the following link for the rest of the description. itfreetraining.com/ap/1b25
References
“CompTIA A+ Certification Exam Guide Tenth Edition” pages 206-212
“The Official CompTIA A+ Core Study Guide (Exam 220-1001)” Chapter 3 Position 5096-5467, 6634-6828
“AT (form factor)” en.wikipedia.org/wiki/AT_(for...)
“ATX” en.wikipedia.org/wiki/ATX
“Mini-ITX” en.wikipedia.org/wiki/Mini-ITX
“BTX (form factor)” en.wikipedia.org/wiki/BTX_(fo...)
Credits
Trainer: Austin Mason ITFreeTraining.com
Voice Talent: HP Lewis hplewis.com
Quality Assurance: Brett Batson www.pbb-proofreading.uk

[@theoldcorporal]

This channel/video deserves more subscription/likes...

[@itfreetraining]

Thanks.

[@ziaurkhan9908]

I still love BTX cases! They had the expansion slots on top and would be serviced from the right, making them much easier to work with.

[@itfreetraining]

Totally agree!

[@dansmar_2414]

very usefull, absolutely! Thank you so much for the high quality and dedication on this channel

[@itfreetraining]

Thanks for watching!

[@Chadgigington]

Thanks for the knowledge sir

[@itfreetraining]

Thanks for watching.

[@ahemednor5201]

✔👍