Service manual
DOUBLE-DENSITY
DISK
CONTROLLER
1
4
,.13
When
you have
inserted
a soft-sectored diskette
and
pressed
RETURN,
the
system
will
print:
Double
Density
<YES>
?
If
you
want
the
formatted diskette to be double-bit density,
simply
press RETURN;
if
you
want
the
formatted diskette to
be
single-bit density, type NO
and
press RETURN.
The
system will
then
print:
Double
Sided
<YES>
?
To create a double-sided diskette (if
you
have
drives
that
handle
double-sided diskettes),
simply
press RETURN.
If
you
want
to create a single-sided diskette,
enter
NO
and
press
RETURN.
The
system
will
then
print:
80
Tracks
<YES>
?
To create a double-track density diskette
(80
tracks
instead
of
40
- again,
you
must have
the
proper
drives), press RETURN. To create a single-track
density
diskette
(40
tracks),
enter NO
and
press RETURN.
When
you have
responded
to
the
message
which
asks
how
many
tracks
you
want
on
the
formatted disk, TEST will
begin
to
format
the
tracks
on
the
blank
diskette. TEST
will
print
one asterisk for each track
it
has
formatted.
When
it
has finished formatting
the
disk,
the
system
will
print:
Disk
Formatted.
CTRL-C
to
continue
diagnostics.
Otherwise,
Insert
a
diskette
into
unit
?
Press
the
RETURN
key
to
format
the
diskette.
If
you
want
to format more diskettes
at
this
point,
insert
another
blank, soft-sectored
diskette
and
press RETURN.
If
you
do
not
want
to format more diskettes,
type
the
CTRL
and
C keys simultaneously.
This
will
return
you
to
the
TEST
main
menu.
T - DRIVE SPEED
The
drive
speed
test checks
the
rotational
speed
of
your
drive. During
this
test,
the
screen
will display
the
relative rotational
speed
of
the
drive
under
test. A series of decimal
numbers,
which
should
be close to
1.000,
will
scroll
up
the
screen,
updating
as
they
scroll.
The
rotational
speed
tolerance is
one
percent.
The
final
value
may
safely
range
anywhere
from
0.990
to
1.010.
Do
not
adjust
the
speed
unless
it
is
out
oftolerance.
Allow
this test to
run
for about
30
seconds;
then
type
CTRL-C.
If
there are
any
numbers
displayed
on
the
terminal
which
are less
than
0.990
or greater
than
1.010,
restart
the
test
and
carefully
adjust
the
speed
adjustment
control
on
the
drive
with
a small screwdriver
until
the
number
is
within
tolerance.
The
speed
adjustment
control may
be
extremely sensitive, so
if
an
adjustment
is necessary,
do
not
turn
it
far
in
either direction.
You
may
wish
to perform this test periodically,
depending
on
how
heavily
your
drive is
used.
The
linear servo loop
which
regulates
the
drive rotational speed makes
this
speed
stable. But as
the
drive bearings wear,
the
speed
may
change
slightly.
Fluctuations
within
the
tolerance are normal
and
may
be attributed to variations
in
temperature
and
humidity.