Re: [hatari-devel] Sync byte on Falcon

[Eero Tamminen <oak@xxxxxxxxxxxxxx>]

Hi,

On 9.9.2023 8.15, Thomas Huth wrote:
> Am Tue, 05 Sep 2023 20:31:56 -0400
> schrieb "Roger Burrows" <anodyne@xxxxxxxxxxxx>:
> > I always thought that bit 1 of the sync byte (0xff820a) on the Falcon had the
> > same meaning as on the ST etc: a 1 bit means PAL (50Hz sync), a zero bit means
> > NTSC (60Hz sync).  But Hatari 2.3.0 disagrees: it always sets the 1 bit unless
> > a monochrome monitor (71Hz sync) is connected.
....>> This seems like a bug to me.  If so, is it fixed in a later release?
> This code has been added by Laurent more than 10 years ago:
>
>   https://git.tuxfamily.org/hatari/hatari.git/commit/?id=27f598b280618b6
>
> I think this comes from "HE AUTHORITATIVE GUIDE TO THE FALCON VIDEO
> HARDWARE BY AURA AND ANIMAL MINE", see e.g.:
>
>   https://bus-error.nokturnal.pl/dl124
>
> It says:
>
> $FFFF820A [R/W] _______0  .................................. SYNC-MODE
>                        ||
>                        |+--Synchronisation [ 0:internal / 1:external ]
>                        +---Vertical frequency [ Read-only bit ]
>                            [ Monochrome monitor:0 / Colour monitor:1 ]
>
> Is anyone with a Falcon able to reproduce this?

Vincent provided test program for this 7 years ago:
https://listengine.tuxfamily.org/lists.tuxfamily.org/hatari-devel/2016/07/msg00012.html


	- Eero