JimDrew wrote:Picasso96 supports screen dragging. The Cybergraphics developer APIs were available for any company making products that needed low-level access. I got the APIs so I could write video drivers for FUSION and PCx, after signing a NDA of course.
Are you sure about that?
I had several Amiga graphics cards, but all used CGFX. For CGFX it worked but did not actually switch video modes like native Amiga chipset.
But I have used Amiberry on RetroPie (and UAE) with Picasso96 emulation and there is no screen dragging as far screens I can see...
Q: Why is there no screen dragging with Picasso96?
A: Hmmm, the sad thing is: VGA chips do not have the features the Amiga Copper offers. There are too many restrictions:
you can do split screen, but you can only show two screens at the same time,
the screen width and RGB formats have to be the same, or it will look very strange,
if both screens are chunky they should use the same palette or it will...
the base address of the second screen must be 0 (ZERO), i.e. when this is not the case, then you will have to move the screen to that position. But this interferes with the memory management of Picasso96...