www.virtualacorn.co.uk/forum

I have just upgraded to VirtualRPC-AdjustSA. As I was already running Risc OS 6.06 on my previous machine I decided, for continuity, to install it over the (almost) vanilla installation. I say almost because I set up an IDE drive before loading the new OS. I particularly wanted to be able to use high resolution and colour modes so noted the instruction to run the ARM7500 machine. This was fine before I installed RO6 with 1280x1024 and up to 16M colours available.
On booting up after the installation the machine is stuck at 16 colours, 1280x1024 resolution and 51Hz refresh rate. Selections on the adjacent menu icons open the option menus briefly and then close them. Additionally clicking on icons in filer windows has no effect and clicking "Menu" on icon bar icons opens and instantly closes the relevant menu.
Any ideas welcome!

RISC OS 6 is currently limited to 2Mb of VRAM when running on VRPC. This will be addressed by a VRPC video driver which is in development - but has shown up some problems that need to be fixed before it can be released.
ROL have publically demonstrated the driver working, but the issues still need to be properly fixed before it can go out to customers.

Thanks Aaron
This was down to my confusion over Select release numbers. The instruction to use the ARM7500 core related to Select 3 (RISC OS 4.39) and not 4 (6.06). Somewhere I had it in my head that Select 3 was RISC OS 6.06 hence my bafflement. I look forward to seeing the new video driver, meanwhile apologies for timewasting.
Brian

Now that Wakefield is about to happen is there any progress on this issue? I still can't use the RISC OS 6 I purchased last year on this machine in any decent screen modes. I gather the driver was to be sorted after the release of the mac version, which has now happened.

The driver that allows RISC Os 6 to use up to 8Mb of video memory is the next priority, but you need to give everyone a chance. VRPC for the Mac only got it's full release last week and we have a show to prepare for.
I suggest coming along to Wakefield and asking.

As a follow-up. RISC OS 6.10 (Select 4i4, released in May 2008) and later versions of RISC OS include the new Video driver and hence can access the full 8Mb of Video Memory when running on VirtualRPC.

May I ask why there is a 8MB limit for the video memory? This is not an academic question because many monitors now support e.g. full HD (1920x1080) or even more (ca. 2000x1500) and cost around 200 Pound or so. Also every PC will offer this resolutions which can not be used on VRPC in full colour.

While 64k colours are probably also fine I just wonder why this limit exists and whether there is any chance it will be extended in the future?

Thanks,
Michael

Thaty's not an easy question. However lets deal with one mistake you've made. Not "every" PC supports full HD (or higher) at 32bpp. A number of smaller netbooks and some budget machines with integrated graphics may not realistically be able to achieive some very hgh resolutions at full colour depth.

Moving on. The A7500 model in VirtualRPC supports "unlimited" video memory (where "unlimited" is difficult to acurately define). As such the Arm 7500 model can display the high resolutions you refer to at full 32bpp. However RISC OS is very "screen-centric" and a lot of stuff relies on the video. You may notice that on a "real" RiscPC the higher the resolution you select the slower the machine goes. This can be very difficult to detect on VirtualRPC running on modern hardware - but the effect is still present (although it might be a fraction of a percent).

Historically a decision was made to make 8Mb the VRAM limit for RISC OS (the A9 has 8Mb, as does the Omega). The Arm 7500 machines don't have VRAM and take the video memory from main RAM. It might be possible to increase this limit but I recall that there were sound technical reasons for the decision.

Ah, ok, I understand. So it is more a timit of RISC OS than that of VRPC. But it is good to know that this limit does not apply to the ARM7500 model.

Thanks,
Michael