Re: Bad video output on RiscPC

On Mon, 2 Oct 2006, Mike Pumford wrote:

> 1024x768 16bit. The kernel is trying to setup 1024x768 8bit for some reason.
> Changing the RISC OS mode to match this doesn't appear to make any difference.
> As the kernel boots it appears as if the VIDC DMA engine is not being pointed
> at the right area of memory. A ghost of the last bit of RISC OS screen data
> appears when the bootloader finishes running and the kernel starts to boot.
> Eventually you can make out the kernel output appearing over the top of this
> but its completely scrambled.

I've done a few experiments.  The problem manifests more severely with 
VRAM installed than removed.  In the no-VRAM case the bottom line of the 
screen doesn't update, but everything else is fine.  With and without 
VRAM, vidcvideo(4) is using the same video mode.  In both cases, my 
keyboard seems not to respond at the "root device" prompt, but caps lock 
toggles correctly, and I can break into DDB wherethe keyboard works 
correctly.  This is all rather mystifying.

-- 
Ben Harris                                                   <[email protected]>
Portmaster, NetBSD/acorn26               <http://www.NetBSD.org/Ports/acorn26/>