Data
Separator
Adjustment
Procedure--DMAF2
Disk
Controller
Adjustment
of
the
data
separator
on
the
DMAF2 disk
controller
board
requires
some
special
equipment
including
a
good
dual
channel
oscilloscope
and
a
disk
formatted
with
all
"1's".
This
adjustment
requires
a
technical
ability
and
should
only
be
done
by
qualified
personnel.
1.)
Connect
channel
A of
an
oscilloscope
to
test
point
TP1l
and
channel
B
to
TP2.
The
scope
should
be
set
on
1
uS/div.
and
2
volts/div.
The
scope
should
be
set
to
trigger
on
channel
A.
2.)
Install
the
special
"All
ones"
alignment
disk
in
drive
0
and
execute
the
SINGLE
DENSITY
LOAD
HEAD
program
below:
(if
the
controller
boad
has
a
jumper
in
the
32K
position
rather
than
the
56K
position,
use
addresses
9020
and
9024
rather
than
F020
and
F024
in
all
the
following
programs:
)
0100
86
DE
0102
B7
F024
0105
B6
F020
0108
20
~=FB
3.)
Adjust
the
DF
pot
for
1 uS
pulses
on
channel
A.
Adjust
the
VCO
pot
for
the
waveform
shown
below:
Tet
Chennel
B
7
od
LS
LS
Le
Kaus —#
4.)
With
the
oscilloscope
controls
invert
channel
B
and
add
channel
A and
channel
B.
The
waveform
should
be
as
below:
Channel
A
&
B
]
|
i
i
(B
inwerted)
|
|
|
|
—H
ws
ke
Adjust
the
VCO and
DF
controls
to
minimize
the
width
of
the
displayed.
spikes.
5.)
RESET
the
computer
and
execute
the
DOUBLE
DENSITY
LOAD
HEAD
'
program
listed
below:
.
:
~
0100
86
FE
0102
B7
F024
—
0105
B6
F020
0108
$20
FB
Adjust
the
MFM
pot
for
the
waveform
shown
below:
Chennet
Aa
8
_
i
__|
=
ee
(B
inwerted)
i
|
|
|
|
l
er
k———_
wS
—__-
6.)
Secure
each
pot
with
a
dab
of
liquid
silicone
rubber
cement.
RESET
the
system
and
remove
the
alignment
disk.
-
20
-