Seen on RISKS-L

From: Sellam Ismail <>
Date: Thu Mar 7 09:57:02 2002

On Thu, 7 Mar 2002, Eric J. Korpela wrote:

> There's more technical info at
> 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

 * Old computing resources for business and academia at *
Received on Thu Mar 07 2002 - 09:57:02 GMT

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:35:10 BST