Re: [hatari-devel] video freq set to 60 Hz instead of 50 Hz for Falcon VGA

[Laurent Sallafranque <laurent.sallafranque@xxxxxxx>]

Hi,


I'm back and I see many things improved.

@Nicolas, do you still need some Videl tests on the real falcon ?

@Nicolas, I had started to improve the videl emulation many years ago, I 
sent you an example of the code taking into account the half HBLs 
frequencies.

(this is the very badly hacked version of hatari I use to play pinball 
dreams, based on hatari 2.0 if I'm right, so many things should be 
rewritten).


Regards

Laurent


Le 06/03/2024 à 22:13, Nicolas Pomarède a écrit :
> Le 06/03/2024 à 19:05, Anders Eriksson a écrit :
> > On Wednesday, 6 March 2024 at 14:48, Nicolas Pomarède 
> > <npomarede@xxxxxxxxxxxx> wrote:
> >
> > > Le 06/03/2024 à 14:29, Nicolas Pomarède a écrit :
> > >
> > > > Hi
> > > >
> > > > I didn't try screenpain yet ; when generating asm source for vga 32 
> > > > Mhz,
> > > > can you compare it to vga 25 Mhz to see what is changing ?
> > > >
> > > > I had the feeling that register-wise only bit 2 in ff82c0 was involved
> > > > in RGB/VGA, by setting clock to 25 or 32 MHz.
> > > >
> > > > I don't see which setting allows vga with a "non vga" clock.
> > >
> > >
> > > nevermind, I tried it myself :
> > >
> > > --- VGA32.S 2024-03-06 14:38:26.928919655 +0100
> > > +++ VGA25.S 2024-03-06 14:41:35.710411188 +0100
> > > @@ -8,14 +8,14 @@
> > > * Monitor: RGB/TV
> > > * 640*400, 16 Farben, 50.0 Hz (interl.), 15625 Hz
> > >
> > > - MOVE.L #$1FE0199,$FFFF8282.W
> > > - MOVE.L #$50004D,$FFFF8286.W
> > > - MOVE.L #$FE01B3,$FFFF828A.W
> > > + MOVE.L #$1900141,$FFFF8282.W
> > > + MOVE.L #$3E004D,$FFFF8286.W
> > > + MOVE.L #$16C0156,$FFFF828A.W
> > > MOVE.L #$2700265,$FFFF82A2.W
> > > MOVE.L #$2F007E,$FFFF82A6.W
> > > MOVE.L #$20E026B,$FFFF82AA.W
> > > MOVE.W #$200,$FFFF820A.W
> > > - MOVE.W #$182,$FFFF82C0.W
> > > + MOVE.W #$186,$FFFF82C0.W
> > > CLR.W $FFFF8266.W
> > > MOVE.W #$0,$FFFF8266.W
> > > MOVE.W #$6,$FFFF82C2.W
> > >
> > > So, clock bit is changed in ff82c0 (which is what Hatari is using at 
> > > the
> > > moment), but it also changes the 6 registers at ff8282 - ff828c that
> > > define the duration for horizontal lines.
> > >
> > > This is sthg that is not supported at the moment, this will require 
> > > much
> > > more code (and a better understanding of all these regs for myself :) )
> > >
> > > Nicolas
> >
> >
> > Yes I figured as much, that's why I asked Zerkman to chip in 
> > previously :).
> > He did the Videl Inside software that allows to configure 
> > non-standard video modes.
>
> I also downloaded videl inside 2.04, this will certainly be a precious 
> source to better understand the Videl and some 'mixed' mode such as 
> this VGA 32 MHz
>
> for reference, PRG and sources can be found here  :
>
> https://demozoo.org/productions/317112/
>
> Nicolas