Date   : Mon, 02 Mar 2009 07:59:17 -0600
From   : jules.richardson99@... (Jules Richardson)
Subject: Fwd: New Screen Modes with ARM7 Co-Processor?

Rob wrote:
> 2009/3/2 Ian Wolstenholme <bbcmailinglist@...>:
> 
>> So, with memory in abundance on the ARM7 co-processor, would there
>> be a way of creating new screen modes, say an 8-colour mode at
>> Mode 0 resolution, or even higher?
>>
> 
> The memory for the display has to be accessible by the crt controller,
> so has to be in the host machine, i.e. the Model B or Master.  It
> can't use memory on the co-processor (of any type).

I suppose you could put a local CRTC on the copro and do some fun things that 
way - turn your beeb into some kind of CAD station...

I don't know if anyone ever did that back in the day - although some copros 
had other local interfaces (e.g. SASI on the Cumana, serial on the Torch 
Tosca, disk on the Torch Graduate etc.).  Maybe there's local video on the 
A500 copro (Dave/Chris?)  although whether it was usable in practice if so, 
I'm not sure.


cheers

Jules