Radio Shack TRS-80 Trsdos & Disk Basic Reference Manual page 35

TRSDOS
Overview
What
makes
a particular filespec
unique?
The
name, extension
and
drivespec
all
figure
into the
uniqueness
of a particular filespec.
The
password does
not.
For example, the following
filespecs refer
to
distinct
files:
A
A/BAS
A/CMD
DRIVECHK:0 DRIVECHK:1 DRIVECHK:2
DRIVECHK:3
However, the following
filespecs
cannot be used
to reference
distinct
files:
RECEIPTS RECEIPTS.AUG3078
RECEIPTS.AUG3
1
78
(There are cases
where two
different
passwords are
used to access
the
same
file;
see
TRSDOS
Library
Commands, ATTRIB.)
More
on Extensions
The
particular
extension
you
use can be purely arbitrary
and
personalized.
Used
this
way,
extensions give
you
an extra three
characters to
work
with
in
creating a suitable
file
name.
Examples:
PAYROLL/AUG PAYROLL/SEP
PAYROLL/OCT
However,
extensions
become more
meaningful
when
they
are
used
as
type
specifiers,
using
some
convention. Here's
a
recommended
set
of extensions:
/BAS
BASIC
program
file
stored in
compressed format
/TXT ASCII
text:
BASIC
program
saved
in
ASCII
form, or
source
file, etc.
/CMD
machine language
command
file
/CIM
core
(RAM)
image
file,
not
necessarily
executable
/REL
relocatable
machine language
program
file
/SYS system program
-
files
which
are part
of
TRSDOS.
Don't
use for
your
files.
/OVn
overlay
number
n
/DVR
I/O driver
module
3-7