As you probably know, any time you use a Windows PC, you're typically ALWAYS going to see the
main installation drive as the C drive. And you've probably seen that whenever you plug
in additional storage devices, whether a USB drive, an internal drive, an SD card or whatever,
that it will get assigned some other letter after C, like D E F and so on.
But you might have wondered, why is the main drive C, wouldn't it make sense to make A:
the main drive? And why, if you plug in more devices, do they NEVER get assigned as A or
B? And how does Windows assign drive letters anyway? And wait, operating systems like Mac
and Linux don't have drive letters, how do THEY work? Well hold on, let's take this one
at a time, and by the end you'll know more than you will ever need about all these questions,
but it's still pretty interesting.
First off, let's not keep you in suspense and longer about the A and B drives. The reason
you never see A and B drives automatically assigned, is they are basically reserved for
floppy disk drives. Yes you heard that right, it's a hold-over from the old days. You see,
back in the early 1980s, the first personal computers actually rarely had hard drives.
They were an optional, but very expensive feature. Instead computers mostly just used
floppy drives. In fact, in the first version of DOS 1.0, it only supported floppy drives,
not hard drives at all. Microsoft then bought DOS and re-wrote much of it and rebranded
it as MS-DOS, and MS-DOS 2.0 did support hard drives.
But even through MS-DOS version 4.0, when the computer booted up, floppy drives were
assigned letters before hard drives were. So for example, if you had four floppy drives
and a hard drive, the floppy drives would get A B C and D, and it would assign the hard
drive as E, as like an after thought. It wasn't until MS-DOS 5.0 that the letter C was always
assigned to the first hard drive. A and B were still only for a primary and secondary
floppy drive, but any additional device after that would would just go down the alphabet,
from D on. And I was curious if Windows 10 would actually assign a floppy drive to A
to this day, so I actually ordered a USB floppy drive, plugged it in, and sure enough, it
got assigned to the letter A.
Now you may notice here that I actually do have an SSD mounted to B. That's because the
A and B reservation is only for Windows automatically assigning the drive letter. But you can actually
do it yourself through the disk manager, and you can even assign a drive to the letter
A if you want. I still have C as my main drive of course, but figured why not use B too for
one of my extra drives, though I did keep A open for whatever reason. Having an A drive
just didn't feel right.
And actually from what i've been reading, it is technically possible to change the main
drive letter on Windows from C to something else. Although it does involve a little bit
of work and messing with the Windows registry I think. So it could potentially break some
stuff. However, that might not be the best idea for compatibility, because some programs
may just assume C as the main drive path, because it pretty much always is, which might
cause issues with that program if it's not. Over the years, I have seen the occasional
program, it's very annoying, but it will only let you install the program to the C drive,
so I have no idea what they'd do if there WAS no C drive.
Alright, so no we know how Windows works with drive letters, but what about Linux and Mac?
Well they don't even have drive letters, the drives just have names, but it is a bit more
complicated than that.
With Linux, you have what's called the Root directory, which is the highest level path
of the entire file system. You can't back up any further, so to speak, sort of like
the My Computer view in Windows, also called "This PC" in Windows 10, where it shows you
all the stuff attached. Of course the My Computer view isn't really a path in itself, it just
shows you the devices. Except in Linux, the root is an actual path, and it's also sort
of like the main C drive in Windows. If you open the root directory, you do see a bunch
of folders. These can be either actual folders on the drive, or so-called 'mount points',
which you can sort of think of as virtual folders or shortcuts.
You might be thinking, wait, if the root folder is as far back as you can go, how does it
handle more drives? Because there is no 'My Computer' equivalent in many linux distros.
Well instead of getting a drive letter, you would instead 'mount' a drive with a path
name. Let me explain. So say you install a second hard drive, you can mount it as /secondary/,
where the first slash is the root directory, and then 'secondary' becomes the name of the
mount point, which again basically is like a virtual directory that goes into the root
directory. And then if you enter into that directory, it will show you what ever is in
the hard drive. And by the way, you can call it whatever you want though, it doesn't have
to be 'secondary', I just made that up. But now for any files that are in there, the path
for them will start with '/secondary/whatever else'.
But what's also different in Linux, is many devices are commonly mounted with a mount
point in a path called 'mount' or possibly 'mnt'. So for example if you have a USB drive,
it might be mounted as /mnt/USB, so to get to it, you'd have to go to the root directory,
then mnt, then USB. You COULD mount it into the root folder, but apparently it's common
practice to organize mounted things into their own directory.
Don't worry if you can't quite wrap your head around the file system in Linux, just know
that instead of using drive letters, Linux lets you mount it as any name and path.
When it comes to Mac OS it's actually similar to Linux, because again there are no drive
letters, it just shows the drive's name. Though Mac does make it a bit easier on users by
simplifying everything by hiding all the root directory stuff. Instead, if you use the file
explorer called Finder, you can view an equivalent of My Computer from Windows, where it does
actually show you the drives, network devices, etc. So it's way more intuitive on Mac, and
doesn't just show you a bunch of root folders, at least to the user. In the back end, I do
believe MacOS still has a file structure similar to Linux, because they're both based on UNIX.
Now you might be thinking, this is so confusing, why is Linux so weird? But you might be surprised
that Windows can ALSO mount drives as paths, not just letters. For example if I plug in
a USB drive, you can see it gets auto assigned the letter L. In disk manager, I can right
click it and select 'Change Drive Letter and Paths', where I can change the drive letter
where it shows L, but I can also add a mount point by hitting Add. Now see the option that
says 'Mount in the following Empty NTFS folder'. NTFS is just the Windows filesystem, so basically
it's saying you can pick any empty folder. So I'll make a folder anywhere, like on the
desktop called WhateverUSB, then navigate to it and select that as the mount point.
So now if I go into that 'folder', (it's not really a folder it just looks like one), well
this is weird, it actually goes into the USB drive. And from here, the path is listed as
being in the C drive, then Users/Joe/Desktop/whateverUSB. And instead if I go to This PC like I normally
would, I can also see the same USB drive as the letter L, with all the same stuff inside
it. So it has two mount points, or two paths that access directly to that drive. I can
even remove the letter L completely, and it will warn you that some programs only work
with drive letter paths. But if I do it anyway, now it doesn't even show under This PC, but
it is still mounted and accesible in the desktop path.
Now what's also interesting, is if I unplug the USB drive, the mount point actually sticks
around on the desktop, but it's just inaccessible. Then if I plug it back in, I can once again
access the drive from that mount point.
Another notable thing about this method of mounting, is you're obviously not restricted
to just 26 letters, in the event that you somehow have more than 26 storage devices.
So say that you do, and you actually run out of letters. What you could then do for example,
is create a folder path in your main C drive, call it something like 'mounted', then create
as many folders as you want in there, and then using the disk manager, link each of
those folders to a different drive. And instead of their paths beginning with a letter, they'd
start with C:/mounted You might realize that sounds awfully similar to how we just explained
how Linux works, except again instead of beginning with the C:/mounted, it's just /mounted/.
That might make it a bit easier to understand how the Linux system works, now that you've
seen how it works in Windows.
Alright, now I know we went a lot further than the initial topic of the video about
the A and B drives, but hopefully now you'll have a much better understanding about how
drive letters and drive mounting works in Windows in general! So let me know what you
think down in the comments.
If you guys want to keep watching, the next video I would definitely recommend everybody
watch is one I made showing you how to become a computer expert in under 15 minutes. Might
sound like an exageration, but not really. So you can just click that right here, thanks
for watching, and I'll see you in the next video.