Advertisement
BACKUP COMMAND
3.8
==
Precautions with BACKUP
guaranteed to be
diffe~ent.
3.8.2 Single/double-sided diskettes
an
EXORdisk
III systems the BACKUP command can be used
to
cop~
or
verify
from
a
Single-sided
diskette
(source
diskette)
to a double-sided diskette (destination diskette),
however,
the reverse is not allowed.
When a single-sided diskette is copied to a,double-sided
diskette,
the system tables (CAT and LCAT) are automatically
adJusted so that
they
reflect
the
true
amount
Or
space
available
on the double-sided diskette.
When a verify takes
place,
the CAT and LCAT Ulill be
different
between
the
two
diskettes;
however, no verification error is displaqed
if the
allocated parts of the tables are the same.
3. 8.3
Four-~Tive
systems
The BACKUP command has the capability
or
copying
to
or
verifying
~ith
any of the three drives (1-3) in a four-arive
system.
It is not possiblel
hOUlever,
foT' BACz.<.UP to sense the
difTerence
bet~een
a
two-~rive
and
a
Tour-drive sqstem.
Thus,
due to the nature o-r
the
two-drive
disk
cont-rolleT''S
Ullth
EXORd·isk
II,
it
is possible to destroq
a
diskette in
drive one if
BAC~UP
is invoked lUith the
"RI!
option
and
if
non-zero
numbers
aT'e
speci~ie~
on
the
command
line
TOl'
<s-unitJ and
<d-unit~.
If the user has a
t~o-dl'ive
system,
it does not make any
sense
for
him
to enter logical unit numbers qn the command
line when invoking
the
BACKUP
command,
since
the
propel'
default
is to copy from drive zero to drive one.
If he were
to
specify to copy from drive
two
to drive three with the "R"
option,
then the diskette in drive one would be accessed and
subsequently destroyed.
3.9 Examples
Many times it is
desirable
to
differentiate
the
two
identical
copies
of diskettes from each other
by
use of the
ID sector information.
The
ID
sector's
contents
can
be
changed during a dis\(ette copy
by
using the
II!"
option.
=BACKUP ; I
BACKUP FROM DRIVE 0 TO 1?
Y
DISK NAME:NEWNAME
DATE(MMDDYY):Ol0978
USER NAME:
=
;'
. /
Page
03-18
Advertisement
