Date   : Thu, 04 Jan 2001 10:58:34 +0000
From   : Paul Wheatley <p.r.wheatley@...>
Subject: Re: VFS: (BBC Video Disk) : Doomsday Project

> 
> >I believe there is only one Domesday specific ROM inside the system (the VFS),
> >although we do have a cartridge (for insertion in one of the slots on
the front
> >of the machine) that contains one chip. Apparently this came with the original
> >Domesday kit (I have seen an identical cartridge with another, non-functioning
> >Domesday kit). Our guess is that its some kind of video chip. Another part to
> >the puzzle is that our Domesday system won't start up with the cartridge in
> >place (not sure if its faulty or not). Does anyone have any idea what this may
> >be?
> 
> Cudgelling my brains, I *think* there were two ROMs - there was the VFS
> as you've stated, which controls the videodisc player via the simple-
> minded SCSI interface (the big 50 way ribbon cable that comes out of the
> back of the Master.  This sits in the space originally intended for an
> internal modem.) The VFS ROM has commands like *VOPLAY, *VOSUPERIMPOSE,
> etc.

This seems to be the only ROM in our working system. VFS was designed rather
nicely, matching the functionality of DFSs and allowing a very
straightforward way of controlling the disc player.
> 
> The other ROM(s) (maybe two in the cartridge) were IIRC needed to start
> the actual Domesday disc running.

This doesn't seem to be the case with the system we have. I am rather
intriuged about his cartridge now tho. Must get to the bottom of it...

> 
> Does the Master not start up at all with this ROM cartridge in?  If
> someone has plugged it in with the machine on, it ill most likely have
> blown up the ROM chip :(

I think the Master starts up but the Domesday software won't start with it
in.

> 
> If you whip the cartridge open, what are the labels on the EPROM chip(s)
> inside?

Not much you can read unfortunately. A hand scribbled label thats half torn
off has the "VDU" on it tho...

> 
> You should have a lead connecting the BBC's RGB output to the videodisc
> player, then a monitor is attached to the player's SCART output.  I
> think the kit also came with a beige Acorn trackball (with a chocolate
> brown ball.)

Yep thats exactly right.

Paul