DOS

Hey guys, it's Makin's, and I'm on with the video on an operating system called DOS. The reason I'm making a video on DOS is because one of our subscribers asked us to, and since I'm taking a request right now, I'm making a video. So let me just get started.

DOS is an operating system that Microsoft sold and made a lot of money off of, and Microsoft itself did not actually make DOS. DOS was based on something called QDOS, which Bill Gates got from a guy named Tim Patterson. So Tim Patterson actually got QDOS; he made it based off of something called CP/M, and QDOS stood for Quick and Dirty Operating System.

So Microsoft bought QDOS, changed it to be DOS, which stood for Disk Operating System, and then gave it to IBM. Now, Microsoft still owned DOS; they still made a lot of money off of DOS, and they had a great deal with IBM in this case. Microsoft didn't actually come up with DOS; they got it from QDOS, which was made by Tim Patterson, who took it from an operating system called CP/M. Since QDOS was far enough away from being like CP/M, there was no legal issue.

So DOS is named the Disk Operating System because it supported floppy disks, and you could even mount floppy disks and bring them to another DOS machine, and you'd be able to read floppy disks. Now DOS has a few disadvantages. It was actually made after Unix, but it was made as a single-user system. There's one user, and you can only really have like one program open at a time.

Now, there are some exceptions, like if you install a kernel add-on or something like that, you can really have more open. But it's not standard to have more than one program open at once. There's no user management and practically no security on DOS. There's no way to shut it down; you quit whatever program you're in, cut all your files written, and then you shut down. Thus, you could only have like 20 files open at once.

So, something like OpenOffice, you couldn't use, since you can only have one program open at once. You didn't have to worry about all these files being read and written to at the same time. So life begins with a disk drive, and that's something Tim Patterson said: the disk drive was just such a great leap.

I'll open up an app I have called DOSBox, which is a DOS emulator for the Mac, and I think it's for other things too. So right here’s DOSBox, and this is really what DOS was like. You can type CLS to switch to any drive. You type the drive name, calling all drives; you can only have like 26 drives or something mounted. All drives start with the letter.

So normally on PCs, even nowadays, there's a C drive, and that would be like C:. To switch to them, with DOSBox you can mount anything as your C drive. So I’m doing tilde /, that’s tough. So now if I type C:, I’m in my C drive. LS doesn’t work because LS is not a command; you can hit DIR for a directory listing.

So CD works. DOS isn't actually made to have case sensitivity, so everything's all caps. So I’ll see you need to content; the up-arrow still works in DOS, but there's not much you can do unlike Command Prompt on Windows. DOS has spent a lot less feature and color.

It's not a command; EDIT is a command. If you want to edit a text file, you take EDLIN, and ED isn't installed on most versions of DOS. So the real way you edit a file, let me just go back to my desktop, can do ECHO whatever you want to put in the file, and then FILE. Now, if you type FILE, it'll show you what's inside a file, and actually, you can put the quotes in, so you can change what's in it.

TYPE reads a file, by the way. So that's how you read a file with this version of DOS. Typing HELP will give you all the commands. COPY will copy a file. DIR will review directory listings. That will delete something. EXIT will of course exit. MD makes a directory, RD removes a directory, TYPE displays the contents of a file, and REN renames one or more files.

You can load a program into like the upper memory, so like almost the background task, and it waits for a key press.