Sage II - CPU Board Circuit Descriptions; MC68000 Processor; Sage Bus

SAGE
rI SERVTCE
I-,IANUAL
[1.0J
AL
IGNI'{ENT
DIAGNOSTIC
PATTERN
2
XIII.O3
PATTERN
2 :
Tracks
6r10r32136164
and
74
are wrltten
with
PATTERN
2.
The
track
and
sector
ID lnformation
are wrltten
wlth track
and
sector
ID
flelds
centered
on
the
track
as normal.
The
data
fields,
however,
are
ntrltten
wtth
a
radlal
dlsplacement
away from
the
centerlLne.
Each
sector's
data
ls
wrltten
a
greater
distance away
as
shown
below.
A
posltlve
value
indlcates
an
offset toward
the splndle
(center
of
the
dfsk)
and
a negative
value lndicates
an offset away
from the
splndle.
PATTERN
2
ntllinches:
65432101234s6
+_+l
.L+l_+++++++
sector
I
2
3
4
5
6
7
8
9
10
11
T2
13
t4
l5
16d
d
d
offse
t
0
0
+2.5
-2
.5
+3.0
-3.0
+3.5
-3.5
+4.0
-4.0
+4.
5
-4.5
+5.0
-5.0
+5.
5
-5.5
The
data
has
been
written progressively
away
from
the track
centerlLne.
As the
sectors
are
read,
the
drive WILL fatl
to read
some
sectors
properly. (Even
good
drlves
cannot read
15
and
16
consistently).
If
the
drlve
ls
allgned,
the first
two
sectors
that
tt
FAILS
to read
should
have
data that
ls equally
offset
from
the
centerlLne.
For
example,
BOTH
sectors
15
and
16 should
fail
is
the
drive ls
allgned as
they
are
borh
offset by
5.5 mlllL-Lnches.
However,
the
drive
ls
out
of
allgnment lf
Sector
14
passes
but
13
fatled.
(or
13
falled
and
L4
passed).
46