Tandy TRS-80 Owner Manual & Programming Manual page 21

A GARBLED UP
DISK
With more than
a million
magnetic
charges on a
disk,
you can
see
why
it is
so delicate.
Any
small
particle
such as a
piece of dust or a cigarette ash
could
distort
its
contents.
A
scratch could ruin
it.
That's
why we
suggest that you keep
the disk
in
its
envelope
when
you're not using
it
—
preferably
upright in a
dust-free
container
—
and
only use a
felt-tipped
pen
when
labeling
it.
To help protect the
disk,
we
encased
most
of
it
in
a black
plastic
container.
However,
as
you can
see,
we
weren't able
to
cover the
entire disk.
The
mid-
dle section
and two
other small areas are exposed
so
the
Computer
can read
and
write
to
it.
Be
care-
ful
not
to
touch the exposed
areas,
not even
to
dust
them.
They
scratch
very
easily.
Since the disk
is
made
up
of
magnetic
charges,
putting
it
next
to
another magnetic
device,
such
as
your
television
set,
could completely rearrange
its
magnetic
code.
Your
information
would
be
lost.
Heat and
sunlight could
have
the
same
effect.
The
same
goes
for
turning your Computer
ON
or
OFF
while the disk
is
in
its
drive.
One more
thing
...
If
you're
in
the
middle
of run-
ning
a disk
program, and
need
to
switch
disks,
we
recommend
that
you
type
this
command:
UNLOAD
fIRTER)
before you switch
disks.
This
way
the
Computer
can put
its
closing
information on
the proper
disk.
If
you
don't type
this
command,
the
Computer
might
put
this
information on the
wrong
disk
and
garble the contents of both
disks.
:
Note
for
BASIC
programmers;
All open
files
must
be closed
before
switching
disks,
UNLOAD
closes
al,
open
files.
'
BACK
IT
UP
All of this
might sound a
little
gloomy
to
you,
even
if
you
are a careful person. This
is
why
we've
included a
command
called
BACKUP.
BACKUP
will enable
you
to
make
a duplicate or
"backup"
copy
of
any
of
your
disks by copying the contents
of
one
disk
to
another.
13