An Overview of PC Input Devices – CompTIA A+ 220-801: 1.12


One of the first things a computer needs is some input, and this can come in many different forms. In this video, you’ll get an overview of input devices that include keyboards, mice, touch screens, scanners, microphones, biometric devices, and much more.

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One of the most common input devices you’ll find on a desktop is a mouse. And that’s one that usually plugs into a USB connection. On the older systems, you may find that they are connecting to a PS/2 port that is on the back of the computer. And if you find a really old system, we were plugging into serial ports to be able to move our mouse around the screen.

We used to have a mechanical ball inside of the bottom of our mouse that would help us determine where we were moving this on our physical desk and that would show up on the desktop of our operating system. But these days, practically all the mice are using optics. There is an LED or a light that’s being emitted and the reflection of that light helps the mouse understand where it happens to be on your physical desk. Unfortunately, there are some surfaces that cause problems with this, especially glass, which does not reflect very well. And in those cases you might want to consider getting a mouse that is specifically designed to work even on a glass surface.

Another popular input device is of course the keyboards that we use. And these days, they’re plugging in through a USB connection on the back of our computer. An older keyboard might connect using one of those Mini-DIN PS/2 connections. If you have a keyboard like this that not only has the standard keyboard functions, but it has these extra buttons across the top or the side, those extra buttons may require specific drivers. So when you plug in and you notice the keyboard is working properly but none of the other buttons are working properly, you may want to check the manufacturer’s website to download specific drivers for this keyboard and the operating system that you’re using.

A more modern input device is something like a touchscreen. We’re certainly using this on our smartphones and our mobile devices. We see it certainly on the tablets that we use these days. And now, you’ll even see a touchscreen being used on a larger desktop computer as well.

This makes it very easy for us to provide input to these devices because all we have to do is reach out and simply touch the screen to be able to manipulate what we’re seeing. Of course, we can also bring up keyboards on the screen and type on the keyboards. So there are a lot of different ways to use these touchscreens to get information into our computing devices.

There are certainly some small niches where people are using fax machines every day. But those numbers are diminishing all the time. These days when we want to take a paper that has printed information and digitize it into our computer, we’re using something like a scanner. It might be a flatbed scanner that is specifically designed to provide the scanning functionality.

These days, it’s very simple to find that in an all-in-one device. So the same device that you’re using to print, the same device you’re using to copy, can also be the same device used to take a piece of paper, scan it into your computer, and now you’re able to save that as a PDF file or a graphic file that you get then email to someone else.

If you’re in a retail environment or you’re in a warehouse environment, then you’re probably also familiar with using a bar code reader as an input device. This takes a barcode that is printed out on a device and you’re able to scan it. And that connection is usually made through a USB connection, although some of the older barcode readers might also use the mouse port on a PS/2 connection as well.

This is often using a laser to be able to read that barcode. So you’ll see the red light coming right out of the end of the barcode reader. You have to be very careful not to view that light directly because lasers can damage your eyes. So make sure you keep it away from your face. But it does give you that feedback. You can visually see that it’s scanning.

If you’re having problems with a barcode reader, then you’re probably going to have to replace it to see if you could resolve the issue. There’s not many buttons or dials or configuration settings on these barcode readers. They’re designed to be these single use function devices.

If you work in an environment where you have a single display and many different computers, then you may be using something like a KVM. KVM stands for keyboard, video, and mouse. This is where you can have a single keyboard, a single mouse, and a single video display and simultaneously connect that KVM to multiple computing devices. And when you want to move from one device to another, you can simply push a button to move from one computer to another computer to another computer. That way you don’t have to have a separate keyboard for every computer, a separate video display for every computer, a separate mouse for every computer. You can simply have a centralized set and simply use the KVM to switch between all of your different computing devices.

It’s very common to use voice as the input to our computers these days. So we need microphones on our mobile devices, on our laptops, and on our desktops to be able to get that audio signal into our computer. This is often integrated into the laptops we use today or the desktops we use today. But you could also get an external microphone that you might plug in via USB connection.

It may also plug in through an analog connection. You can see this 1/8 inch, 3 and 1/2 millimeter connection on the end of this microphone. And usually there’s a microphone input that will take that connection into your computer. If you want a really good sound with the microphone, we generally would use a digital connection to plug that microphone into your computer.

More and more, we’re seeing these biometric devices also used as another security tool, especially on our portable devices that have a tendency to sometimes get away from us. And if somebody else is trying to use our laptop, they’ll notice there might be a biometric fingerprint reader right on the laptop. And although somebody else had that laptop and even if they had our password, they would still not be able to get into this laptop and see our data, because you have to have our fingerprint to be able to authenticate properly into that operating system.

Here’s one of my favorite input types for a computer. That’s the gaming input. And you might have a joystick, which is the single stick with multiple buttons on it. It’s very common, of course, to see these gamepads that you might have on a console-based system. You can also use very similar type gamepad type systems on our PCs as well. And they’ll usually, both the joy stick and the gamepads, plug in through a simple USB connection.

If you’re someone unlike myself that has true artistic abilities, then you might be able to take advantage of something like this digitizing pad. These are very large pads and they have these specialized pens that are with them that allow you to effectively draw on the digitizer. So if you wanted to create some artwork or you simply wanted to use that as another input device into your computer to replace perhaps your mouse, this is a great way to consider doing that.