Re: [MiNT] XaAES sources for FreeMiNT 1.16.3

[Peter Persson <pep.fishmoose@gmail.com>]

On 9 dec 2009, at 18.20, Paul Wratt wrote:

> a "must have", but an initial start to the sequence should be the
> ability to choose a screen rez and color depth, and I think that is
> what VDI cannot do, which is what a virtual worksataion should be able
> to do.

The XBIOS video API on the CTPCI is compatible with that of the original Falcon TOS. It's also compatible with the extensions provided by the Milan XBIOS. Personally, I think this works fairly well, apart from being too hardware dependent (different calls to set colour registers on different incarnations of the shifter, for example). There is also a slight problem regarding the allocation of video RAM. There is an undocumented TOS call for this (Srealloc()), but I think it re-allocates VRAM instead of just allocating new space.

> From memory frame buffers can be redirected or re-pointed (on PCI/ISA
> hardware anyway), which will beat bliting any day.. this may be
> dependant on video mode and/or card support, I cant remember exactly,
> but I know VESA VBE can supply this sort of support.. which comes back
> to choosing a video rez, and how to do that thru VDI (current or
> new)..

Most graphics cards can specify the framebuffer base address, but it's still limited to the onboard VRAM.

-- PeP