Re: [hatari-devel] VDI resolution limits

[Eero Tamminen <oak@xxxxxxxxxxxxxx>]

Hi,

On 05/11/2018 07:29 PM, Eero Tamminen wrote:
> On 05/11/2018 06:53 PM, Thorsten Otto wrote:
> > > Any idea why these mouse related reads happen only with VDI mode,
> > > and only when mouse moves *horizontally* in this area?
> >
> > I would bet that the vertical limit is restricted to not exceed
> > the screen height, but in the horizontal direction you may need
> > to read an additional word, and the logic only masks the values
> > out if it is out of screen bounds, but the read is still performed.

Sorry, no, it doesn't explain why the crash happens only when
the 16-pixel horizontal offset is crossed.  There's no crash
if the mouse goes to 16x16 bottom right corner in vertical
direction, or is moved within that area.  Crash happens only
when it arrives there in horizontal direction.

There must be some operation that TOS does exactly at 16-pixel
offset from the right, not before or after it.


> I just wonder should there really be the same amount of bytes (768)
> padding as with TOS, currently I added just enough for the mouse
> pointer (16x16 pixels).


	- Eero