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Read about how to handle .ZIP files using DOS.

To open a DOS box from the Windows 3.x or 95/98/ME, NT/2000 or XP desktop:

Select the Run option in the File or Start menu, type in the word COMMAND and press the Enter key. When you have finished working in DOS, type the word EXIT at the prompt, and you will be returned to Windows.

In Windows 2000 and XP it is even easier! The command processor has a shorter name: you type CMD after clicking Start. The old COMMAND still works though, for the benefit of those unfortunate enough not to know about CMD.

  • All the older executable files (programs) in this collection can be run in DOS (Version 3.2 or higher) or Windows 3.x. Under Windows 9x, 2000 and XP some of them fail to perform on some computers. I don't know why. The items that can't keep up with the times are some parts of the HNS Neuroanatomy tutorial, which were written for use on older computers in the hope that newer ones would honor the old DOS programming conventions. The DOS programs written entirely in ASIC work just as well in Win98, Win2000 and XP as they did in DOS 4.
  • The chemical calculation utilities and the large Neuro-MCQ program work well in Win98, 2000 and XP.
  • The program for printing histological methods (files in histotec.zip) will not run under 98 or more recent versions of Windows.
  • DOS utilities that need a mouse don't work properly in Win2000's DOS emulator (CMD).

Alt+Tab  provides the easy way to jump about among open Windows programs. A DOS box is just another window!  The keypress  Alt+Enter  changes an insipid Windows screen into a full-size DOS text screen, which is much more readable than the tiny print provided by Windows. To go back to an ordinary window, press Alt+Enter again.

Using DOS when your computer has been set up to use Windows.

What are DOS and MS-DOS?

They are acronyms for computer operating systems sold by MicroSoft, to work with computers that contain Intel central processors (CPUs) with numbers ending in 86 (8086, 80286, 80386, 80486) or the name Pentium, which was given to later models instead of 80586, 80686 etc. There are other trade names such as Celeron, for similar CPUs.

DOS was the name that IBM gave to the Disk Operating System that they bought from Bill Gates, who had bought it from some other spotty youth for $100 in the late 1970s. MSDOS is the same thing when it's bought from MicroSoft. When ordinary people talk about "DOS" they mean any of this family of operating systems. The DOS operating system was improved and refined by MicroSoft up to about Version 6, circa 1995. Later versions have been tailored to Windows 95 (and Windows 98), which pretends to be the operating system but is in fact a program run by DOS, just as were Windows 3.1 etc.

Windows NT (versions up to 4.x) and Windows 2000 (which is really NT version 5) are different. They are primary operating systems, not DOS add-ons, but they can run many programs written for Windows 3.x and 9x (and Windows ME, which is an update of Win98). Microsoft's NT/2000 operating systems include a DOS emulator that will run many but not all programs originally written for DOS. Older games were said by Microsoft to be the only DOS and Windows (3.x, 9x, ME) programs that might have failed to run under NT/2000. That statement is not true.

Windows 2000 is a much better operating system than 95/98 because when a program crashes or freezes you can usually escape without having to reboot the computer. With Win 9x crashes frequently occur even when all programs appeared to be running normally. If a DOS program crashes under Win 9x you have to reboot. Under Win2000 you lose the offending program and often the DOS box in which it was running, but other Win2000 applications are unaffected.

How to run a DOS program

With the DOS operating system you type a short (maximum 8 letters) one-word command to get the computer to do something. The command may be followed by an argument (a second word; sometimes more than one word) and/or a switch (usually one or two letters preceded by a slash or a hyphen). Some DOS commands are internal. Well known examples are DIR and DEL.

Thus:   DIR C: /w

displays the file listing for the current directory on Drive C. (Note that directories are called "folders" in Windows 9x.)  The /w is a switch that makes the listing "wide" with the file names arranged in 5 columns across the screen. Without this switch, DIR provides a list with only one file per line, but each line includes other information (file size, date and time), which is not shown when the /w switch is used.

Another example:   DEL A:*.BAK

will delete all files that have the extension .BAK in the current directory of Drive A. The asterisk (*) is a wildcard symbol that means "any string of characters."
Some internet search engines let you use the asterisk in the same way.

Internal DOS commands are not names of files. An external command is the name of an executable file. You can recognize an executable file by its name, which ends with the .COM or .EXE extension. (A batch file, with the extension .BAT is another kind of executable file, but it is outside the scope of this brief introduction to using DOS. If you know about batch files, you do not need to be reading this!)

An executable program is any program that does something. It is started by typing its name at the DOS prompt. The full name of the program is typically something like WORDGAME.EXE and you can type the whole thing, but all that's needed is the part before the dot - WORDGAME in this case. You can type it in upper or lower case letters, or a mixture of the two. After typing the name press the Enter key, and the program will run. All this is, of course, exactly the same as the way you start a program from the Run option of the File menu (Win 3.x) or of the Start menu (Win 9x, NT, 2000 etc). The name of the external command may be followed by additional arguments or switches.

An example:   WS7 C:\WINDOWS\WIN.INI /N

This command tells the executable file WS7.EXE (the last DOS version of WordStar) to open the file WIN.INI (which resides in the directory \WINDOWS of drive C:) in non-document mode (WordStar's jargon for a plain text or ASCII file).
This command includes an argument, which is C:\WINDOWS\WIN.INI, and a switch, which is /N.

If you use only the occasional DOS program, you can run it by entering its name (with arguments and switches if they are needed) at the Run option of the File menu (in Windows 3.x) or of the Start menu (Windows 9x, ME, 2000). Unless the DOS program ends with a pause, such as prompting you to press a key, its output may disappear, returning you to the Windows desktop before you can read it. For this reason it is generally preferable to open a DOS box.

How to unzip a .ZIP file in DOS

First, you need the un-archiving program PKUNZIP.EXE. If you don't have this file, you can click here to download it. The file must be placed in a directory that is in the DOS command path.

The PATH is a list of directories, with their names separated by semicolons, that you can see by entering the command PATH at the DOS prompt. A line of text will appear on the screen, looking something like this:


This means that when you type an external DOS command (such as PKUNZIP) the computer looks for its file (in this case PKUNZIP.EXE) first in the root directory C:\, then in the Windows directory, then in a directory called C:\UTIL (which is where I keep utilities such as PKUNZIP.EXE) and finally in ..\ which is the next directory back from whichever one you are currently in. It's useful to have ..\ in the PATH if you keep data files in a directory subordinate to one that holds a program. For example, you might have WordPerfect (WP.EXE) in C:\WP and letters that you write in C:\WP\LETTERS. If you are in that letters directory you can start the word processor by typing WP, even if C:\WP is not named in the PATH.

The PATH statement is set in a text file called AUTOEXEC.BAT that resides in the root directory of the boot drive (usually C:\). You can change the PATH by editing AUTOEXEC.BAT with a text editor such as the EDIT.COM program that comes with DOS. The Windows NOTEPAD is also a text editor. Do not use a word processing program to edit a text file. To edit your AUTOEXEC.BAT file enter this command at the DOS prompt:


Look for a line that begins with the word PATH. It may be in upper or lower case. Possibly there will be no PATH statement. If you need to make one from scratch put something like:


The statment needs a line to itself. Notice that there are no blank spaces and that each directory specification (except the last) is followed by a semicolon. You can modify the PATH whenever you want. You must reboot the computer for the changes to take effect.    End of mini-lesson on the PATH.

It's a good idea to download .ZIP files into their own special directory, and keep them there for a while. I collect such files into D:\ARCHIVES\ZIPS and will assume that you, gentle reader, do the same. If you do otherwise, simply substitute your own directory's name in the instructions that follow. You will also need a directory to receive the unzipped archive. Let us assume that you have downloaded MOLWT29D.ZIP (the DOS version of utilities for simple chemical calculations) and that you want to put the extracted files in C:\RESEARCH\CHEM which will be a new subdirectory of C:\RESEARCH.

First, make the new directory and go into it, by typing the following 4 commands:

MD CHEM         
CD CHEM         

The prompt will now be   C:\RESEARCH\CHEM >

Next, unzip the archive by entering the following line:

(The only space is between "pkunzip" and the argument.)

Some text will appear on the screen to tell you what's happening. When the DOS prompt reappears, you can enter DIR to see a listing of the files that now reside in the current directory. The original archive (such as MOLWT29D.ZIP) is unchanged.

Returning from a DOS box to Windows

To close a DOS box, type the word EXIT at the prompt, and hit the Enter key.


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----------------------------- Last updated: January 2007