Atari PC Owner's Manual page 30

A name can have up to eight characters (letters, symbols, or num­
bers). An extension is optional and can have up to three charac­
ters. (Directories do not usually have extensions. ) A period always
divides the extension from the name. The following characters can
NOT be used in a name or extension:
. " " / \[]:!
In addition, the names and extensions listed below are reserved by
MS-DOS for special purposes and can only be used for those
purposes:
Names Extensions
AUX LPT1
COM1 LPT2
COM2 LPT3
COM3 NUL
CON PRN
Names can be clues to the specific information in the file, such as
TAXES for tax information, or TAXES85, TAXES86, TAXES87 for a
series of tax information files. Extensions often indicate the type of
a file. For example, .TXT may indicate a document file created with
a word processor.
In many cases you can specify a set of filenames by using two
special characters called wildcards: the asterisk(*) and the ques­
tion mark (?). Wildcards are used when you want to perform the
same operation, such as copying or deleting, on a group of files.
An asterisk in a filename stands for all characters and combina­
tions of characters, and can replace an entire name or extension.
For example, the wildcard designation
• •
means all filenames. A filename can often have an asterisk as the
name while spelling out the extension. For example,
*.Doc
means all filenames with the .DOC extension, such as
LETTER.DOC
ATARI.DOC
MOM.DOC
24
+
< > =
.APP
.BAT
.COM
.EXE
.SYS
?