Date : Sun, 26 Apr 2009 11:47:50 -0500
From : jules.richardson99@... (Jules Richardson)
Subject: Domesday
Darren Grant wrote:
> Sadly the reason that domesday1986.com has disappeared is that Adrian Pearce
> the person responsible for it has recently died.
Indeed. I *might* have a copy of all his code (we spent many hours throwing
ideas back and forth) - and I know that all his hardware was left to
Bletchley, so it should 'live on' there.
> With regard to the suggestion that the Domesday data be stored on a flash
> card. The problem is that the LaserDisc contains both analogue video frames
> and the text data encoded on what would normally be the audio tracks. As
> Joel said the LV Player contains a genlock with the LV generating the video
> and the BBC overlaying text.
The conclusion Adrian and I came to was the same as yours; that it'd be useful
to make a modern PC 'look' like a VP415 player. To do that it'd need an RGB
capture card and a bastardised SCSI interface*, along with suitable software
to emulate VP415 functions. Video output could just be via a modern PC video
card and display, rather than requiring output hardware to interface to a
vintage monitor.
I really don't remember if Adrian had all the analogue data backed up in a "PC
friendly" format - if he didn't though, then the Camileon lot at least should
have (the chap I was in touch with there has moved on to the British Library,
but I suspect he can still prod people if needed)
* it's possible that a stock SCSI card could be used; the VP415 "isn't quite
SCSI" as it doesn't support all of the SCSI CCS, but the commands that the BBC
sends are at least CCS-friendly. I'm just not sure there's any functionality
currently in Linux/Windows/whatever to run a SCSI HBA in target mode...
> The question is why would you want to replace the LaserDisc, presumably
> because the drives are so unreliable and the disc's are not that common.
Sure. The drives aren't the most reliable of beasts, and like you say the
discs aren't *that* common. Plus I have seen some discs that have started to
deteriorate (rot setting in from the perimeter) so they're not going to last
forever anyway.
> So building a box to replace
> the LV-ROM drive would mean you may as well use an emulator to emulate the
> BBC as well and run the whole thing on PC hardware, I can't see the
> advantage of running it on a BBC.
It'd be fun ;-) I suspect that *technically* dealing with BBC video rates
isn't too hard - but practically it's certainly beyond me (I have no idea how
to go about building a PCI card or USB interface).
Similarly running a SCSI HBA in target mode with a modern OS is likely a real
can of worms involving a lot of nasty code.
Sadly Adrian never got an RML Domesday setup working before he passed away -
it would have been interesting to see how that performed (the RML variant
didn't use SCSI it seems, but controlled the player via the RS232 interface;
that'd be a lot easier to interface to a PC, but I think some of the BBC
functionality was lacking in the RML version for just that reason)
Copyright is a *major* issue, by the way. The BBC have basically lost track of
copyright owners for all the data on the discs, which means that they'd
probably try to squish any attempt to freely distribute an 'alternative'
Domesday setup. However, I imagine that something could be done for owners
which already had the LVROMs, which would at least ensure the survival of the
data for now.
cheers
Jules