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can be preserved over time. It is interesting
to consider that in some cases emulation
may involve a simpler copyright question
than migration, simply because less is
actually changing when preservation
action is taken.
Based on your experience with
CAMiLEON, what do you think
are the most important issues for a
project to consider when undertaking
long-term data preservation?
I
t is too easy to consider preservation
action as `long-term digital preservation'
without actually thinking about the real
long-term practicalities of what is being
attempted. Both Cedars and CAMiLEON
attempted to use examples from the past to
inform what our challenges will be in the
future. Most assumptions that current stan-
dards will survive are flawed and, although
technologies like XML will certainly make
digital preservation easier, I do not believe
they are the all-encompassing solution that
many are suggesting. A common sense
approach to what is and what isn't likely
to survive into the future, based on the les-
sons of the past, is a good starting point. I
think the CAMiLEON approach to soft-
ware longevity and the identification of
elements of a programming language that
will be present in future languages is a use-
ful way of looking at preservation as a
whole.Whatever kind of digital technology
you are looking at, some aspects of it will
be inherited by future developments and
some will fall by the wayside due to poor
design. If you can minimise your use of
what will probably be lost in the digital
evolution of the future then preservation of
what you create will become much simpler.
A
discussion of the legal and IPR issues
relevant to making CAMiLEON's
emulation of BBC Domesday accessible is
available at http://www.si.umich.edu/
CAMILEON/ reports/IPRreport.doc
many resources are inextricably tied to the
medium on which they are published
despite this being a very short-sighted poli-
cy. By selecting an appropriate abstraction
for the Domesday data we were able to cap-
ture the elements of the resource significant
for its use and encapsulate these in byte-
streams that are easy to preserve and can
move from medium to medium over time.
O
ne rather alarming issue was high-
lighted by the range of offers we had
from commercial vendors to `assist' with
our work. One manufacturer offered us a
special polymer that they guaranteed
would preserve a CD-ROM for 100 years.
They were unable to answer how we
would preserve a CD-ROM player for
that length of time and I could guarantee
them there won't be CD-ROM players
in the computers of 2103AD! The myth
that long-lived media equals long-lived
preservation is still worryingly popular.
What are some of the other issues
that surround CAMiLEON's
Domesday emulation?
T
he data in Domesday comes from
many different sources, and copyright
was cleared for use specifically in the
Domesday publication, meaning that con-
forming with intellectual property rights
standards is not a simple matter. Does an
emulated version of Domesday that runs
on a modern computer without the origi-
nal discs or hardware that it ran on when
published constitute a new version of the
resource or a copy? There are little or no
precedents in law for these kinds of issues.
The precedents of the paper world do not
map simply to those of the digital domain
and this makes the IPR situation very
complex. We would argue that the whole
point of the preservation work is to create
a `copy' of BBC Domesday which as far as
the user is concerned looks exactly like
the original, while ensuring that this copy
documentation and virtually no software
to actually test the emulation, debugging
the system was particularly time-consum-
ing.We had to use a great deal of experi-
mentation to get things to work. In
extracting the data from the discs we
exploited the very early SCSI 1 support
used in the laserdisc player. But modern
operating systems wouldn't recognise the
player as an SCSI device and we had to
go through a lot of trial and error to get
the communication working.We were for-
tunate that members of the public saw the
media coverage of our work in early 2002
and donated bits of Domesday hardware
found in their lofts.We went through a
number of the specialist LV-ROM
videodisc players and without the dona-
tions we simply wouldn't have got the
work done.
Fortunately, some examples of the
original system were still available to
you, albeit incomplete. Was the data
rescued just in time?
M
ost of the really difficult problems
we faced were due to the long time
gap between the creation of Domesday
and its preservation. If we had conducted
the rescue 10 years earlier it would have
been far easier.The timeliness of preserva-
tion work is a crucial issue that Domesday
really underlines.Would we be able to res-
cue Domesday if we left it another 10
years? I'm sure we could, but it would be
at far greater expense.
Storage technology becoming obso-
lete led to the need for CAMiLEON's
emulation in the first place. How did
you ensure the longevity of your work?
T
he Cedars Project (http://www.leeds.
ac.uk/cedars/) pointed out quite
rightly that the medium upon which digital
resources are recorded is not part of the
message that the resource is conveying.Yet