Service manual
DOUBLE-DENSITY
DISK
CONTROLLER
1
4
..
9
To
respond
to
this
question,
check
to make
sure
the
red
light
on drive 0 is glowing.
If
it is,
enter
Y.
Otherwise, enter N
and
turn
to
Page
4-13
for
an
explanation of
the
message
you
receive.
If
you have
responded
Y to
the
preceding
question,
the
system
will
print:
Selecting
Drive
One.
If
this
is
a
non-existent
drive
for
your
system,
Answer
'y'
to
the
following
question.
Is
Drive
Select
Light
On
and
Head
Loaded?
To
respond
to
this question,
check
to make
sure
the
red
light on drive 1 is glowing.
If
it
is,
enter
Y.
Otherwise, enter N
and
turn
to Page
4-13
for
an
explanation
ofthe
message
you
receive.
The
program
will
continue
to activate
the
drives
in
this
way
for drive 2.
In
general, you
should
respond
Y if
the
drive exists
and
the
red
light glows,
and
N only
if
the
drive exists
but
the
drive
light
does
not
come on.
If
all
the
drive motors work properly
and
the
program was able
to
successfully select all
the
drives,
the
system
will
now
print:
Attempting
to
verify
the
operation
of
the
Head
positioning
system.
Please
stand
by
...
The
program
will
now
attempt
to
position
and
reposition
the
disk
drive
read/write
head,
much
as it
would
as
if
it
were
reading
from or writing to a diskette.
If
this
test is
successful,
the
program
will
print:
Controller
appears
to
be
ok.
Please
continue
on
to
selection
3
or
4
to
make
further
checks.
If
you
do
not
receive
this
message, refer to
the
error messages
on
Page
4-10
for
an
explanation of
the
error message
you
receive.