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Date   : Fri, 05 Jan 2001 12:23:10 +0000
From   : Paul Wheatley <p.r.wheatley@...>
Subject: Re: VFS: (BBC Video Disk) : Doomsday Project

> 
> First I have found some links
> http://www.cix.co.uk/~jgriffiths/cv/CV.html
> 
> The first appears to be to a CV from someone who worked at acorn on the data
> retrieval from the video disk.

Great. I've contacted Jonathan to see if he's interested in helping out.

> 
> The second link
> http://www.atsf.co.uk/dottext/domesday.html
> Has some detail about the Doomsday project and the laser disk player.

*:-) I think our posts must have crossed...

> 
> I was thinking if a way can be found to tap into the FM data which is read
> from the disk. This is in a digital form could some how be clocked into a
> computer at 7Mhz. Then we will have a perfect record of the original raw
> data just in case we needed to make another pressing of the laser disk.
> 
> Software can be used to decode FM data to analogue, and I have a few
> computer programs which will decode a colour image from a digitised raw
> composite video signal. So this might be a feasible method of conversion to
> another format without loss.
> 
> Or you might have to result to expensive digitising and mpg encoding
> equipment like Real Magic DVD recorder which is a hefty £2000.

Intercepting the FM data would be very handy, but how we'd go about doing
this is well beyond my field of experience. Does anyone else have any ideas
of a way forward on this?

Failing that we have two other alternatives, one of which you mention.

Firstly, simply digitising each of the images from the video signal. We have
some kit to do this and will probably do it this way, assuming the FM data
method proves to tricky.

Secondly, the BBC has the original film onto which all the photos were
scanned. This will obviously be the best source if the intention is to get
the best quality pictures.

Which brings us to the question of authenticity. Do we want to have the best
possible pictures or do we want an authentic reproduction of the original,
even if that means reproducing the graininess of the pictures on the original
system? Is that in fact a property of the original system we want to
preserve?!

I think the ideal answers to that are both yes and no! Ideally we would want
high quality pictures digitised from the original film. We would also want
digitised pictures from discs, that show a future user the kind of
(relatively poor) quality of photos that were available to users of the
system in the eighties. The cost of doing both (not to mention the massive
amount of data we'd have to mess around with) may make this dual strategy
impossible, but it would certainly be worth exploring it in the context of
our research.

> 
> I can send you a solidisk program which will allow you to save a rom from
> ROM/RAM to floppy. I will dig this out and send to you if you want?

Yeah that'd be great. Either a floppy or bytesteam I can zap down the line
from PC to BBC.

Thanks again for your help Chris

Paul
-- 
Camileon Project Officer
http://www.si.umich.edu/CAMILEON/
0113 233 5830

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