 The magazine of the Melbourne PC User Group Beginners' Basics: Part 1 Ron Wilby |
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Hello there to all beginners and everyone else reading this. In this new series we're going to get down to the basics of what makes your computer run. Then we'll show you lots of things about how you can make it run the way you want it to. This calls for a good understanding of dear old DOS.
The Role of DOS
fm deafened by the screams of "I don't use DOS, I use Windows only." Sorry, screamers, if you use Windows, you are using DOS. What Windows does is provide you with a "graphical user interface," a fancy sounding name for a different way of getting DOS to do what you want done.
Windows and DOS
In pre-Windows days we all typed commands at the DOS prompt, which looks like C:\ with a blinking line. This is called "Command Line Computing." That prompt is DOS saying "what is your command, Master?" Don't let the salesmen fool you. This is the fastest way by far to use your computer, and you can also do many more things. The problem was, DOS involves somewhat of a "learning curve," our slang name for finding out how to use something. People are lazy, or short of time, or both (me too) and Windows offered a much shorter learning curve (read quicker start).
The Windows method, the "Graphical User Interface," simply means that the various operations you want to perform are shown as little diagrams. You access these using your mouse, thus you have very much less to learn. There are two disadvantages. First, the whole thing runs much slower and needs more memory and hard disk space. Second, you don't develop any understanding of what you're really doing. If you continue to learn about your computer, this lack of understanding will hold you back. If we dig deeper, there is much more to Windows than just the graphical interface, but that's somewhat above beginners level. So, to really know what you're doing, and to use the full power of your computer, you need some DOS basics, and that's what we're about in this series.
"What Is DOS?"
DOS is just an acronym for Disk Operating System. We all need an operating system, and most of us use Microsoft's MS-DOS. There are many alternatives to DOS and the most common and the closest relative is IBM's PC-DOS. A few years ago these two were virtually identical, but there was a falling out between Microsoft and IBM, and thus there are now significant differences between their DOS versions. OS/2 is an alternative operating system of great merit, but here we're talking about DOS.
But, what is DOS? One answer is, it's a software package. It comes in a cardboard box containing some floppy disks and a manual. The Reference Manual is most important, you should keep it safe and handy.
Your computer can't read what's in the box, so you must transfer the programs from the floppy disks to - our computer. This simple transfer is called "loading" the programs, but often you have to carry out a slightly more elaborate process called "installation." This occurs because many programs exist in compressed form on their original disks, and must be expanded while being transferred to your computer. Also, installation involves telling the program about your printer, monitor and maybe other hardware.
Do You Really Have DOS?
If your computer has DOS already installed, you should have, carefully stored, your original disks with their Microsoft labels. The DOS Reference Manual should be close to your desk, and, if you're cautious, working copies (which you have made) of your Microsoft disks. I used to make working copies of everything. That resulted in a house full of 360 kB floppies, so now I just keep the originals safely in another room after I've installed the programs to my hard disk. Regrettably, some dealers will supply you with a machine with DOS already loaded, but no disks or manual. This sounds like black eye patches, cutlasses and all the trappings of software piracy and is unacceptable. Go back to your dealer (if you can find him) and demand your genuine DOS disks and Manual.
Either on-screen instructions or your manual will tell you how to get to the DOS prompt. If you are using the DOS 5 or 6 shell, you press F10 and Enter, which gives you a drop-down File Menu. From that select the exit option which is Alt+F4. Do that and we can start. You should now have a prompt at which you can type your commands. This prompt usually looks like C:\ followed by a blinking line, and is at the top left of your screen. Type VER alongside the prompt and Enter to find the version of DOS you are using. The correct answer today is 6.2 or 6.21. If you have version 5, you are in good shape, but earlier versions would be holding you back. To improve your version (it's called upgrading), see
The Age Green Guide on Thursdays for a dealer who will sell you an Upgrade Package.
Floppy Disks
Floppies come in two physical sizes, 5.25-inch and 3.5-inch. We should call these 13cm and 9 cm respectively but few people do. Each physical size comes in two different storage sizes, or capacities. Roughly, one byte equals one character (letter or figure) and one kB is 1024 bytes. One megabyte (MB) is about 1000 kB . One page of what you are now reading is equivalent to about 7.0 kB . I'm being vague here because there is some disagreement about the exact value of a Megabyte, and I've been criticised by readers on this point. I personally find all sizes in regular use except the 3.5-inch medium density 720 kB , which I rarely encounter.
The 5.25-inch Double Density can hold 360 kB of data, the High Density 1.2 MB. The physically smaller 3.5-inch disk holds 720 kB in Medium Density and 1.44 MB in High Density form. There is also a 2.88 MB version in this size, but as yet most computers can't read it. Now, if you have only one disk drive, it should be 3.5-inch because many programs are only available on that size disk. To cope with the world of computing, you'll find a 5.25-inch drive a great asset, but if that is your
only floppy drive you have problems. Lots of people are still using that size, though, especially for Shareware and Club members exchanging disks. In terms of dollars per MB of storage, the high density versions are the best, with the 5-inch being the most economical.
Commercial programs, such as DOS, are easy to load. Your computer has one or two floppy disk drives and usually one hard disk drive. You can't see the hard drive, but the floppy drive(s) have doors in the front through which you can slide in your disks. Your disk drives are called A, B, and C. C is usually your hard disk drive. If you have only one floppy drive, then it is always A and you don't have B. You can have more, but these'll do for a start. You put a colon (:) after the letter to show that it means a disk drive, so you have A:, B: and C:. To make these columns reasonably intelligible, I use a grammar and spelling checker, called Grammatik. These colons in disk drive names send the thing mad. It criticises my punctuation, tells me the colon is the end of the sentence and so on. If my English was better, I could throw Grammatik away, but unfortunately it's always finding mistakes!
Loading Your Program
To start loading your program, put your first disk in your Drive A: floppy disk drive and if it is a 5.25-inch drive, shut the door. If you have two floppy disk drives, you may need to experiment to find which is which. If you're quick enough, you'll get the answer from those screens full of information which appear while your computer is starting up. You need to get to your DOS prompt as described earlier, then type A: and Enter. You will then see the DOS prompt for the A: drive, which will look like A:\. From here, you should have instructions in your manual or sometimes (in small print) on the disk itself. If more than one disk is involved in the installation, there'll be on-screen instructions to tell you when you must remove the first disk and replace it with disk 2 and so on.
What is an Operating System?
An operating system provides the interface between you and your computer. It executes the commands you enter from the keyboard and manages the system resources such as disks, printer, mouse and monitor (screen).
The operating system allows you to run other programs, called Application Programs. We can think of these "Applications" as running on top of DOS, and they need to be designed for use with DOS. Don't buy OS/2 Applications when DOS is your operating system. These Applications are the programs such as word processors, databases and spreadsheets for which, (most likely), you bought a computer in the first place. What are they? I'll explain as we go along with the series.
Often your computer will be set up so that a secondary program, called a "shell" will take control soon after you start up. This shell puts a menu on screen so you can just use the arrow keys to select what you want to do next. Such a shell comes with DOS. Surprise, surprise, it's called DOSSHELL. If you're not keen about that one there are many others available.
To learn about the basics of DOS and thus the basics of using your computer, you'll have to get behind this shell and do some command line computing, starting from the DOS prompt.
That's all for this month. Be back next month .......
Reprinted from the September 1994 issue of PC Update, the magazine of Melbourne PC User Group, Australia
