Radio Shack TRS-80 model III Owner's Manual page 30

TRSDOS
The name,
extension,
and
drive-specification
all
contribute
to the
uniqueness of
a
file
specification.
The password
does
not.
It
simply
controls
access
to the
file.
File
Names
A
file
name
consists
of
a
name
and an
optional
name
extension.
For
the
name,
you can choose any
letter,
followed by up
to
seven
additional
numbers
or
letters.
To
use
a
name
extension,
start
with a diagonal slash
/
and add no more
than
three
numbers
or
letters;
however,
the
first
character
must
be
a
letter.
For example:
MODEL3/TXT
NAMES/ A
12
TEST
INVENTORY
AUGUST/A
15
TEST1
DATA11/BAS
WAREHOUS
TEST
1
/A
are
all
valid and
distinct
file
names.
Although
name
extensions
are optional, they are useful for identifying
what
type
of data
is
in the
file.
For example, you might want
to
use the
following
set
of
extensions:
/BAS
/TXT
/CMD
/DAT
for
basic
program
for ascii text
for
machine-language
command
file
for
data
One
advantage of using extensions
is
that
you
can
tell
by
just
looking
at
the
directory
what kind of information
a
file
contains.
Another advantage
is
that
trsdos
can recognize
certain extensions.
For
example,
if
a
file
has the extension
/cmd,
the
trsdos
will load
and attempt
to
execute
that
file
when
you
type: filename (ENTER) omitting the
extension /cmd.
Drive
Specification
If
you
give
trsdos
a
command
such
as:
KILL TEST/A trsdos
will
search for
the
file
test/a
first
in
Drive
0,
then
in
Drive
1 ,
2,
and
finally in
Drive
3 until
it
finds the
file.
Anytime you
omit
a drive-specification,
trsdos
will
follow
this
sequence,
unLess
you use
the
master command.
It is
possible to
tell
trsdos
exactly
which
drive
you want
to
use
by
specifying
the drive.
A
drive specification consists
of
a
colon followed
by one
of
the digits
0,
1
,2,
or
3,
corresponding
to
one
of the four drives
you might
be
using.
For example:
KILL TEST/A
:
3
tells
trsdos
delete the
file
test/a
on Drive
3
only.
23