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REPAIR COMMAND
22.2 -- ID, LCAT, CAT, Bootblack Sector Check
The operator must respond with either a
lIy"
or an
liN",
The
"Y"
response
will
cause
the ID sector's unused area to be
filled
with binary
zeroesl
as it is sup·posed to be.
The
"Nit
response
~ill
cause
REPAIR
to leave
tha ID
sector alone.
After
the
ID
sector
has
been
checked.
REPAIR will
examine the
Lockout
Cluster
Allocation
Table
CLeAT)
for
readability.
If
the
LCAT
sector cannot be read,
REPAIR
will
display the rollowing messages:
**PROM I/O ERROR-STATUS=31 AT 2E8A ON DRIVE l-PSN 0002
LOC~OUT
C.A.
T.
READ
ERROR
WRITE TO DISK TO ATTEMPT TO CLEAR ERROR?
The operator must respond with either
a
"Y"
or
"N"
to
the
last
question,
IT
an
UN"
is entered, REPAIR cannot continue
to check other system tables
SlDce
subsequent
checking
is
based
on the validity o-F the LCAT.
Thus,
the message
DISK
IS
NOT FIXABLE
i s dis p
1
aye dan d con t r a
1
ret urn edt
0
MDOS.
I
f a "
Y
fI
res
p
0
n s e
is given,
REPAIR
will
attempt to
re~rite
the LCAT sector.
r-F
an
error
develops
during
the
write,
the
sector will be
considered unfixable (as will
the
diskette).
The
message
shown above will be displayed and
MDOS
given control.
1 f
the
L
CAT
s e
I!
tor
i
s
rea dab
1
e
J
0
r
i
of
r e Ulr
i
tin g the
sec tor c
1
ear s the e r
l' 0
r
I
REP A I R
wi
I I p
roc e e d t
0
c
h
e c
k
the
contents of the
LCAT.
The LeAT must show that the diskette's
system
tables
in
the
first
cylinder
are
locked
out
(unavailable
-For
allocation
by a -FileL
and all regions of
the
diskette
that
correspond
to
non-phYSical
locations
(beyond
the
highest
physical sector number) must be locked
out.
r-F either o-F these two criteria is
not
satisfied,
the
LCAT
will
be considered destroyed.
REPAIR
~ill
display the
message
LOCKOUT
C. A.
T.
IN
ERROR - RECONSTRUCT?
and awai t a response from th
e
operator.
An
UN"
response
wi 11
make
the
LCAT
unfixable.
REPAIR
will
display a message to
t hat e -F
oF
e
c tan d ret urn to
MDOS.
A" Y
II
res p
0
n s
e
\II
ill
c
a
use
a
new
LCAT
to
be rebuilt by REPAIR.
In order
to
build
a new
LCAT,
the entire diskette is read in an attempt to
find
any
deleted
data
marks.
The
deleted
data
marks signify
bad
clusters round by the DOSGEN surface test (Chapter 10),
All
clusters
containing
deleted
data
marks will be locked out
again
automatically
by
this
process.
In
addition,
the
operator can lock out an additional area of the diskette (for
the same reasons as specified
in
Chapter
10).
Arter
the
diskette's
surface
has
been
completely
~ead,
REPAIR will
Page
22-05
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