VECTOR
GRAPHIC, INC.
Briefly,
this
example means
that
the diskette in the A drive is read:9nly, or
wri
te
protected.
If
this
is
the
Vector
Graphic
System
Diskette,
it
will
probably
have
a
silver
write-protect
tab
over
the
notch
in
the
upper
right-hand
corner
of
the
diskette.
The diskette in drive B
is
both read and
write
enabled; you
can
copy information onto
it
as well as use programs which
already
exist
on
it.
The
SDace
column indicates
the
amount of storage area,
in kilobytes,
left
on
the
diskette.
As
you
see,
you can run any programs, transient commands or otherwise, from
any mounted diskette
or
disk, even
if
you
are
not
logged
onto
that
drive
at
the
CP/M
command
level.
As long
as
the
file
exists
somewhere
in
the
computer, you
can
get
to
it
somehow. The way you can find
out
whether
or
not
the
program
exists
is by finding·
the
~
you want. To understand this
better,
let's
take a closer look
at
how
Vector 4 CP/M assigns and understands
its
file names.
Vector 4 CP/M
File
NaolilJi: Conysmtions
Files
are
identified
by
a
two-part
code, consisting of the file name and
the
extension.
The
file
name
usually
describes
the
contents
in
some way;
the
extension
indicates
the
type
of
file
or
the
language
in which the file was
programmed.
You
can think of the name as the way you call the file, and the
extension
as
the
way
the
computer knows how to interpret
it.
File names
can
be up to eight characters long, extensions three
characters,
and
the
two
are
separated
by a period.
So
a typical entry, with a filename of
SAMPLE
and an
extension of
DOC
might look like:
SAMPLE-DOC
Furthermore, file names
can
be
"ambiguous" or "unambiguous".
An
unambiguous
file
Dame (ufn
for
short)
refers
to
a keyboard entry which describes one file
and
one
file
only.
The
example above, "FILENAME.EXT", is an unambiguous
file
name
according
to
CP
1M.
An
ambig'J,lous
file name (or aln) means
that
what
you
enter
might
refer
to
several different files.
An
ain
is made possible
by a
CP/M
function called the "wild card".
The
wild cards used by Vector 4 CP/M
are
the
symbols?
and
*.
The question
mark
tells
the
computer
to
accept
any
sin~le
character
located where you
placed the
? The asterisk stands for any cQmbjnation of characters needed
to
fill in the eight file name characters or three extension characters.
Vll-24
7100-0001 9-01-82 - Rev. A
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