Re: [Rpcemu] Can't get Monitor def file to work under 0.8.10/5.20

On 12 Aug 2013, George <george.greenfield@tiscali.co.uk> wrote:
> In message <537a295b6crpcemu-sub@aconet.nl>
> Frank de Bruijn <rpcemu-sub@aconet.nl> wrote:
> > In article <a98a207a53.George@george/greenfield.tiscali.co.uk>,

> > > However, the RISC OS-Configuration-Screen-Resolution available
> > > options don't go higher than 1280 x 1924 x 16M x 60Hz for the
> > > particular Benq MDF I'm using
> >
> > That's to do with the maximum pixel rate.
> >
> > See http://www.riscosopen.org/forum/forums/10/topics/1624
> >
> > I have added these to my MDF and they work:
>
> [MDF details snipped]
>
> Thanks, Frank: I've done likewise and you're right!

In an earlier post, George said that RPCEmu 0.8.10 / RO 5.17 could
display 1280 x 1924 x 16M x 60Hz whereas RPCEmu 0.8.10 / RO 5.20 could
not. The hardware is emulated by RPCEmu, which is the same version, in
both cases, so that could not account for the difference.

RO 5.20 'protects' the emulated hardware by setting the value of
VIDCBandwidthLimit to 2000000000. For a 32 bbp display, that implies a
pixel rate of 500 MHz, which should not be a problem for the host
Windows machine, and which is certainly greater than the 148 MHz pixel
rate, required George's display.

I'm somewhat confused as to what is actually limiting the display.

Incidentally, in http://home.marutan.net/arcemdocs/VIDC20.pdf , which
relates to 'real' hardware, ARM states that the chip is capable of a
maximum 100 MHz pixel rate, not 110 MHz, as mentioned in
http://www.riscosopen.org/wiki/documentation/show/RiscPC%20Hardware

Tony




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