Date   : Sat, 12 Jun 2004 18:50:28 +0000
From   : Jules Richardson <julesrichardsonuk@...>
Subject: Re: network-aware scrolling message thingy

On Fri, 2004-06-11 at 19:24, Sprow wrote:
> In article <1086979761.15873.456.camel@...>,
>    Jules Richardson <julesrichardsonuk@...> wrote:
> > (Of course a 4x4 Cub 'video wall' hooked up to a camera to give large,
> > grainy digitisations of museum visitors would be pretty neat too...)
> 
> When I converted 18 Cubs to accept composite video and welded up a 6x3
> monitor rack for them, using them as a video wall was definitely on the
> cards.
> 
> Then I graduated, ah, happy days,

Ha ha!

Well the video wall's looking more realistic project all the time. Other
people seem keen, plus I got a lead on another school full of unwanted
BBCs and Cubs earlier, so a source of hardware may have been found.

I need to really sit down and think about architecture. One BBC per
screen, linked by Econet, with *something* controlling them seems like
the way to go (rather than having to build hardware for one BBC to
control more than one display) - plus of course a rack full of BBC
boards would look pretty nifty :-)

One approach would be for the controlling system to take an image, split
it into chunks according to how many screens/BBC's are hooked up, send
each chunk to an off-screen image on each BBC over Econet, and then tell
each BBC on the network to display it's off-screen image at once. 

That method relies a) on Econet being fast enough to transfer the data
in a reasonable amount of time, and b) for the BBC to have enough memory
to buffer an entire local image off-screen in memory. Likely not a prob;
my memory's a bit hazy on both transfer speeds of Econet and how much
memory the various BBC video modes need.

I also need to ponder the controlling system configuration - one the one
hand a later Acorn will have the CPU power to split up and image, and I
probably have a spare digitiser board already. On the other hand, BBC
hardware is highly hackable and I know nothing about programming later
Acorn machines...

Lots to think about...

cheers

Jules