Английский язык в информационных технологиях. Демкина Л.М. - 35 стр.

                                                       Default drive
Your computer may have either one or two disk drives, which MS-DOS knows as drives A: and B:.
The default drive is the one which MS-DOS uses unless you tell it to do otherwise. It is shown by the prompt which MS-DOS
displays:

    A>        drive A is the default drive
    B>        B>     drive В is the default drive

To change the default disk drive, enter the new drive letter:

A> B: changes the default drive from A to В
B> A: changes the default drive from В to A
                                                                    File
Computers store information on disks in files. A file is a collection of related information such as a computer program or the text
of a letter.
Each file is given a unique name, and each filename is stored in a directory. To find out about the files in a directory, use the
MS-DOS command DIR.
When referring to a file, you must use a file specification. This consists of a pathname, a filename and an extention (if there is
one). As an example, to reference a file on drive B: called FRED.BAS (where the default drive is 'A') the correct file
specification would be:
B:\FRED.BAS
File extention can be up to three characters long and are used to identify the contents of a file.
MS-DOS automatically defines the meaning of some file extentions. Others can be assigned as you wish. For example, .TXT can
be used to indicate a text file.
                                                               Directories
MS-DOS lets you organise the files on your disk into directories. Directories are a way of dividing your files into convenient
groups. A directory may contain any number of files, but it is often more convenient to separate the files into subdirectories.
This method of organising the disk is rather like a tree where the files are the leaves of the tree and the directories are the
branches. (The first directory is usually called the "ROOT".)
You can have more than one file (leaf) with the same name provided that the files are in different directories. The diagram shows
two instances of FILE57 - the first in subdirectory 1, the other in subdirectory 2.
Each directory has at least two entries, even when otherwise empty. These are '. ' and '.. '. The '. ' specifies the name of the
current directory and the '.. ' the name of the parent directory.
MS-DOS needs a pathname to find its way to a particular file. The pathname is a series of directory names followed by the
required filename, each separated from the last by a backward slash (\). If a file specification does not begin with \ the first part
of the specification is taken to be default, or current, directory.
                                                            Default Directory
You must tell the computer which directory it is to use as its current working directory - that is, the directory you wish to work
in. Do this with the CHANGE DIRECTORY command (CD). The current working directory is often called the default directory.
To change the current directory use CD followed by the. pathname of the directory you wish to use.
                                                               Command
A command performs some commonly used task, such as creating a directory or copying a file or disk.
MS-DOS has internal and external commands.
Internal commands are available at any time when your computer is running. External commands are loaded from disk only
when needed.
                                                                Batch File
To avoid repeatedly typing the same set of commands for a commonly used task, put the command sequence into a special file
called a batch file.
You can then carry out the entire sequence (or batch) simply by typing the name of the batch file. Commands in batch files are
carried out as if the individual commands were typed at the terminal.
You can create a batch file by using the line editor (EDLIN), or by using the COPY command.
If there is a batch file called AUTOEXEC.BAT in the ROOT directory when the computer is started up, it will be executed
automatically (AUTOmatically EXECuted BATch file).
Batch file may be made more useful by use of the SET, IF and GOTO commands.




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