Date   : Fri, 01 Mar 2002 11:06:44 -0000
From   : "Colin Fraser" <colin@...>
Subject: Re: BBC Domesday on the telly

> -----Original Message-----
> From: owner-bbc-micro@... 
> [mailto:owner-bbc-micro@...] On Behalf Of Dave Gorst
> Sent: 01 March 2002 10:50
> To: bbc-micro@...
> Subject: Re: [BBC-Micro] BBC Domesday on the telly
> 
> Can't think that the interface to the laserdisc player would 
> be particularly
> difficult - there's quite a few old laserdisc players about 
> with a serial
> interfaces, which I guess you could connect to the RS432 IIRC 
> (have a look
> at the Dragons Lair emulator Daphne for instance). Was there 
> anything odd
> about the player or disc format? Otherwise could we not write 
> something to
> step through and play the full contents of the disc and use a PC video
> digitiser card to capture the result?

The BBC sees the laser disks as a big read-only hard drive over the SCSI
interface for reading the digital data.
It sends commands over the serial or SCSI interface to the drive to
playback sections of video.
The video outputs from the BBC and the Videodisc player are genlocked,
and the videodisc player has some special circuitry to provide nice
stable still frame images.

Seems to me like you could extract all the data accessible via SCSI read
block commands, write them into couple of huge files, and add support to
any of the nice BBC emulators around to simulate the file system access.
Then you'd need to capture all the video/audio that could be played back
from the discs, and provide some interface for the playback commands
sent from the emulated BBC to be converted into instructions to
MediaPlayer or somesuch to play back the appropriate piece of AV,
overlaid on your emulated BBC screen.
Sounds like a fun project...
If someone wants to give me a Domesday setup, I'll be happy to hack at
it for a while ;-)

Colin f