7 Mar
2002
7 Mar
'02
4:23 a.m.
Date: Mon, 4 Mar 2002 09:51:50 -0000
From: "LEESON, Chris" <CHRIS.LEESON(a)london.sema.slb.com>
Subject: Metro: Time runs out for Domesday discs
The BBC's 1986 Domesday Project (a time capsule containing sound, images,
video and data defining life in Britain) is now unreadable. The data was
stored on 12-inch video discs that were only readable by the BBC Micro, of
which only a handful still exist. The time capsule contains "250,000 place
names, 25,000 maps, 50,000 pictures, 3,000 data sets and 60 minutes of
moving pictures.". The article notes that the original Domesday Book
(compiled in 1086 for tax purposes) is still in "mint condition".
[Source: London *Metro*, 01 Mar 2002]
Additional comments of my own:
The BBC Micro, along with the original Sinclair Computers, was the computer
that sparked off the "computer revolution" in the UK. The BBC Micro was
especially popular in schools, whereas the Sinclair computers were more
popular in the home.
To be fair, the 1986 Domesday Project was in the days before the really
rapid changes in technology came into force - the BBC Micro was not a bad
choice of platform then, especially when you consider that there were very
few other choices available (50,000 pictures alone take up a lot of space).
Moral/Risk: If you are wanting long-term data storage, the format is just as
important as the materials.
This is not a new problem - It has appeared in Risks before (RISKS-21.56:
'NASA data from 1970s lost due to "forgotten" file format' for one...),
but
is worth keeping in mind. I still have an old Commodore 64/128 disk with my
(very) old account details on it - not that I have a C64/128 any more. My
permanent records, however, are the printouts.
PS: "Domed... We are all Doomed..."
6 Mar
6 Mar
10:56 p.m.
On Thu, 7 Mar 2002, Eric J. Korpela wrote:
>Date: Mon, 4 Mar 2002 09:51:50 -0000
>From: "LEESON, Chris" <CHRIS.LEESON(a)london.sema.slb.com>
>Subject: Metro: Time runs out for Domesday discs
>
>The BBC's 1986 Domesday Project (a time capsule containing sound, images,
>video and data defining life in Britain) is now unreadable. The data was
>stored on 12-inch video discs that were only readable by the BBC Micro, of
>which only a handful still exist. The time capsule contains "250,000 place
It's pretty silly when folks write articles like this and don't bother to
do even the minimum of research, which would have revealed that there are
plenty of BBC Micros still in existence. If the writer is referring to
the video disc player (which would make more sense) then I can believe
that there may only be a "handful" of complete systems left in existence,
but this begs the question of why, inspite of them, this makes the
videodiscs "unreadable".
Duh.
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
* Old computing resources for business and academia at www.VintageTech.com *
7 Mar
7 Mar
7:16 a.m.
At 12:56 PM 3/7/2002 +0000, Sellam Ismail wrote:
It's pretty silly when folks write articles like
this and don't bother to
do even the minimum of research, which would have revealed that there are
plenty of BBC Micros still in existence. If the writer is referring to
the video disc player (which would make more sense) then I can believe
that there may only be a "handful" of complete systems left in existence,
but this begs the question of why, inspite of them, this makes the
videodiscs "unreadable".
You'd think the actual problem must be that the discs are
becoming unreadable, or that kind of LD player is hard to find
or maintain, or that there was some custom controller that's
in need of repair. I doubt BBC Micros are rare in the UK.
You'd think an emulator would be created to recreate the gizmo.
Here's a free business idea. I'm sure there's going to
be a market for CD and CD-R recovery ten years from now,
after we've all used our supply of nearly-free CD-R blanks.
Similarly, I wish there was a device for low-level recovery
of 8mm video tapes. I'm lamenting a year or more of tapes
I recorded of my young kids, on a Sony camcorder that
suffered from cheap capacitors that rot over time (leaving
a fishy smell) and cause the recorder to fail slowly,
as well as loosening tape guides. Playback of the most
recently recorded stuff worked, and I never bothered to
check tapes on a second deck, or check older material.
It drifted out of sync.
In both cases, you'll need a device that deals with error
recovery at lower-level bit streams, or digitizing and
reinterpretation of what's there - a sync regenerator,
if you will. Like Jerome Fine's digitizing 9-track.
- John
9:10 a.m.
It's pretty silly when folks write articles like
this and don't bother to
do even the minimum of research, which would have revealed that there are
plenty of BBC Micros still in existence. If the writer is referring to
the video disc player (which would make more sense) then I can believe
that there may only be a "handful" of complete systems left in existence,
but this begs the question of why, inspite of them, this makes the
videodiscs "unreadable".
There's more technical info at http://www.atsf.co.uk/dottext/domesday.html
The videodisk players were specially modified for this purpose.
"The data channel appears on a SCSI bus ... and SCSI had only just been
standardised at this time. This means that the player looked to the host
computer like a very large, somewhat slow, read-only hard disc. We had
never used a CD-ROM at that point. A read-only version of the BBC Micro
hierarchical disc filing system, now called VFS (for Videodisc Filing
System), is used to access the data in a way that adhered to the filing
system standards. In this way any code written for one filing system
could be used with another, providing both use the same subset of the
whole standard. Write-only systems obviously do not have sector write
primitives or means of modifying file attributes for example."
It sounds like images were stored as PAL frames and were converted to RGB
for mixing with the BBC RGB output.
Eric
1:57 a.m.
On Thu, 7 Mar 2002, Eric J. Korpela wrote:
There's more technical info at
http://www.atsf.co.uk/dottext/domesday.html
The videodisk players were specially modified for this purpose.
"The data channel appears on a SCSI bus ... and SCSI had only just been
standardised at this time. This means that the player looked to the host
computer like a very large, somewhat slow, read-only hard disc. We had
never used a CD-ROM at that point. A read-only version of the BBC Micro
hierarchical disc filing system, now called VFS (for Videodisc Filing
System), is used to access the data in a way that adhered to the filing
system standards. In this way any code written for one filing system
could be used with another, providing both use the same subset of the
whole standard. Write-only systems obviously do not have sector write
primitives or means of modifying file attributes for example."
It sounds like images were stored as PAL frames and were converted to RGB
for mixing with the BBC RGB output.
If someone actually knows how the data is encoded then it doesn't sound
very "unreadable" to me.
Sellam Ismail Vintage Computer Festival
------------------------------------------------------------------------------
International Man of Intrigue and Danger http://www.vintage.org
* Old computing resources for business and academia at www.VintageTech.com *
5:21 p.m.
On Thu, 7 Mar 2002, Eric J. Korpela wrote:
I suspect the practicality is that, although technically feasable to convert
to a DVD, _copyright_ issues prevent any commercial project from
doing so (starting with the arm and a leg than ordnance survey would charge
for the map data, and following with the impossibility of contacting all the
other copyright holders) and the amount of work required (and legal
minefield) being too much for a hobby project.
Andy
>From: "LEESON, Chris"
<CHRIS.LEESON(a)london.sema.slb.com>
>
>The BBC's 1986 Domesday Project (a time capsule containing
sound, images,
>video and data defining life in Britain) is
now unreadable.
The data was
>stored on 12-inch video discs that were only
readable by the
BBC Micro, of
>which only a handful still exist. The time
capsule contains
"250,000 place
It's pretty silly when folks write articles like this and don't bother to
do even the minimum of research, which would have revealed that there are
plenty of BBC Micros still in existence. If the writer is referring to
the video disc player (which would make more sense) then I can believe
that there may only be a "handful" of complete systems left in existence,
but this begs the question of why, inspite of them, this makes the
videodiscs "unreadable".
9:05 a.m.
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9:42 a.m.
William Donzelli wrote:
I thought I read the
Mars lander machine readable data was lost
>This is not a new problem - It has appeared
in Risks before (RISKS-21.56:
>'NASA data from 1970s lost due to "forgotten" file format' for
one...), but
>is worth keeping in mind.
Urban myth. Every bit of every mission is available on CD-ROM. from 1976? because the format the data was saved in was
not documented
and the programmer on the project died, and the computer used was
scrapped.
--
Ben Franchuk - Dawn * 12/24 bit cpu *
www.jetnet.ab.ca/users/bfranchuk/index.html
10:03 a.m.
I thought I read the Mars lander machine readable data
was lost
from 1976? because the format the data was saved in was not documented
and the programmer on the project died, and the computer used was
scrapped.
No. Funny that you mention the Viking mission - one of the guys at RCS
has the actual tapes. Plain ol' 9 tracks.
The thing that might have been the seed for all of this "NASA lost data"
mythology is that the original telemetry tapes may be gone. When anything
was launched by NASA (or the military), the telemetry receivers would
record the information in analog format - the video coming right off the
receivers. This was done so the data was recorded in real time,
reduntantly, even if a computer crashed - the "dumb" tape decks would
record regardless of the world around them. Only later would the analog
tapes be read and converted into digital data.
Telemetry tape drives, as with most lab grade tape drives, were built to
a number of standards, some of which died off and faded into obscurity.
NASA, however, was smart enough to covert the data into a far more stable
format before the telemetry tapes would have decayed. I would not be
suprised if it was only hours after the data came back to Earth.
William Donzelli
aw288(a)osfn.org
8 Mar
8 Mar
1:01 a.m.
In any sufficiently large organization there will be lost files,
ones that are physically present but "lost" due to the owner
keeping important contextual information with him and either
leaving or dying. These lost files could be either paper or
digital; doesn't matter much.
sufficiently large = 15+ people
sufficiently old = 10+ years
- - -
The thing that might have been the seed for
all of this "NASA lost data" mythology
I remember hearing that evidence of the polar ozone hole had
been faithfully recorded for years, and that only by using graphics
to view the collected data did it become obvious that it had been
happening all along.
There must be other stories. NASA is both large And old.
John A.
7 Mar
7 Mar
9:51 a.m.
>This is
not a new problem - It has appeared in Risks before (RISKS-21.56:
>'NASA data from 1970s lost due to "forgotten" file format' for
one...), but
>is worth keeping in mind.
Urban myth. Every bit of every mission is available on CD-ROM.
10:25 a.m.
Depends upon how you define mission. I have NASA data
that doesn't
appear anywhere except in my possession. Not that it would be of much
interest.
I do not know how to define it - I would have to ask my source. Certainly
it means the spaceshots and the probes.
The "forgotten file format" problem I'm
recalling is actually a forgotten
record encoding problem that exists with some data stored on mylar (IIRC) punch
tape. The data exists and is readable, but how to convert it into something
physically meaningful has been lost.
Well, I could believe that some high level data formatting might have
faded into obscurity (damn programmers not leaving comments in their
code!), but as far as the raw data - that is available,
even the boring parts.
A great number of people, including those writing articles for respectable
magazines and papers, tend to paint a broad picture of actual data
being lost due to fading media and obsolete, scrapped computers. This is
simply false. The Census people also get damned as well for the same
crimes, and once again, false. Simply false.
In regards to that "1 in 5" myth about the Interstates - even
*Smithsonian* magazine is guilty on that count!
William Donzelli
aw288(a)osfn.org
8326
days inactive
8327
days old
12 comments
8 participants
participants (8)
-
allain＠panix.com -
andyh＠andyh-rayleigh.freeserve.co.uk -
ard＠p850ug1.demon.co.uk -
aw288＠osfn.org -
bfranchuk＠jetnet.ab.ca -
foo＠siconic.com -
jfoust＠threedee.com -
korpela＠ssl.berkeley.edu