On Sun, 29 Oct 2000, David Brownlee wrote:
> On Fri, 27 Oct 2000, Chris Gilbert wrote:
> > > > > 	Is the A7000 special with respect to needing the correct amount
> > > > > 	of video RAM set in the bootloader? Does anyone know how to probe
> > > > > 	that?
> > > >
> > > > I just guessed at the amount.  I just randomly chose 1024K.  Later on
> > > > I also tried 2048K and that worked as well.  So, I don't think it
> > > > matters that much.  I'm not using X yet, it might be more important
> > > > for that.
> > >
> > > 	Wasn't there something special about the A7000 and Video RAM (such
> > > 	as it didn't have any and just used some of the normal RAM?)
> >
> > Yes, you use the DRAM, as can a RPC with no VRAM.  The amount needed is
> > the same as under Risc-OS, eg 1024x768 at 256 (1byte) colours is about
> > 768KB.
>
> 	So the value is only needed on a machine without VRAM? On a
> 	machine with 1MB of VRAM can you set it to 2MB to use 2MB of DRAM
> 	with higher resolution/bpp?

I'm not actually sure on this.  might be timing issues if doing that (and 
maybe DMA issues?)

> > Perhaps it's time to start up that wish list of things to try to get into
> > 1.6 (and smaller stuff into 1.5.x)
>
> 	For 1.5 would it make sense to default the value to 768KB?

Probably, but time is pressing for 1.5.

> > I know that there's a list of PR's that need to be looked at.
>
> 	Definitely - can you submit one for this?

Might have to pester me again, but I will eventually.

Chris