Yokemate of Keyboards
Posts: 4977 from 2009/1/28
From: Delaware, USA
Quote:
Andreas_Wolf wrote:
> considering the fact that we now have support for cards with 512MB or more
> (up to 2GB) of vram, this limitation shouldn't exist.
As I wrote in comment #52 (and if I'm not mistaken), MorphOS still can only use up to 256 MiB VRAM because RAM + VRAM must fit into 31-bit address space. Or has this changed with MorphOS 3.10 or 3.11?
Interesting issue. We map vram into address space?
I must admit, I am not that familiar with how Amiga related OS' use RTG cards.
When we were writing drivers for VGA cards under OS9 68K, graphics were not mapped into processor space.
But I can see why this would be natural with an Amiga related OS as legacy Amigas mapped video in chipram.
In fact, I always like memory mapped video, even when it was something crude like the VDG used in Tandy Color Computers.
VDPs that mapped through a window like the TMS9918 were more difficult to code for.
Still, I'm left wonder how vram can be mapped like this when it's accessed through a bus (PCI, AGP, PCIe, etc).
"Never attribute to malice what can more readily explained by incompetence"
