Multiple displays

Bearing this in mind, if it ever came to pass that a RISC OS USB driver for DisplayLink were written…

What is the mechanism for registering the presence of another display to RISC OS?

This seems to be covered on the Proposed GraphicsV enhancements page.

Don’t forget the companion forum thread

Well, my DisplayLink adaptor arrived this morning. The good news is that it only has two USB endpoints: a bulk OUT and an interrupt IN. No requirement for isochronous. Also there is an open source driver for Linux, which is clearly approved of by DisplayLink. None of it looks too scary.

I must get the “CMOS RAM” writing finished before I play with the display adaptor, though.

Hi Dave,

I think the official open source driver for Linux does not support the compression.

Have a look here for some more example sourcecode and explanation of how the DisplayLink prototcol works.

This does sound interesting but before I get too excited: what would this mean regarding resolution?

The max resolution you can get from a DisplayLink device depends on the exact chip being used. The entry level model supports 1280×1024/1440×900, the high end model supports 1920×1200/2048×1152.

I have one of the mid-level devices, I have successfully used 1600×1200 with Windows. As long as you don’t use it to display a video, it performs very well. But performance is dependant on available CPU power on the host. However, I know that several people use a DisplayLink device with a SheevaPlug, so in principle our humble ARM should be powerful enough.