[hatari-devel] Improved right border with 224 bytes overscan + hscroll

[Nicolas Pomarède]

Le 14/12/2010 21:05, Anders Eriksson a écrit :
> On Tue, 14 Dec 2010, Eero Tamminen wrote:
>
>> The extra pixels were on middle of the last line, not at borders.
>> I guess Anders needs to comment on this one. :-)
>
> Hello,
>
> Hatari shows 276 lines, while a real Atari show 274, so you will see two
> scanlines garabage in some programs with Hatari.
>

Hello,

to be more precise on this, I used some values by Paulo Simoes in a post 
on atari-forum about what should be shown by emulators :

"With a single 60/50 switch you can get 46 lines of lower border bitmap.
Flix from DF says in his document that you can get 2 lines more with a 
second 60/50 switch. I never tested that and will not do so as those 
lines ar not really interesting as you can not see them on most of the 
monitors/TVs.
Now depending on the demos, you can get some bad results if you show the 
complete 46 lines of the lower border as you may be displaying parts 
that were not supposed to be shown or are not visible with most 
monitors/TVs.
For example, the Overscan Demos uses 45 lines of the lower border 
because for a long time i believed that was the correct value, then i 
tested it by reading the final video address and foun out that i had in 
fact 46 with my machine. So if you display 46 lines you will see some 
garbage pixels on the last line.
[...]
My advice is then to use 400x276 for SainT"

So, I chose to display 47 lines in the bottom border (which gives 
29+200+47 = 276). Maybe there're really 1 or 2 lines less on STE than on 
STF.

Nicolas