Re: [hatari-devel] Sync byte on Falcon

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 06/09/2023 à 02:31, Roger Burrows a écrit :
> 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.
>
> If that's really the way the hardware works, I'm extremely puzzled that Atari
> defined a PAL/NTSC bit in the video modes settable for RGB/TV, and that TOS4
> writes 0x02 to the sync byte (indicating 50Hz sync) for an RGB screen when the
> PAL/NTSC bit in the mode set to 1; and 0x00 to the sync byte (indicating 60Hz
> sync) for an RGB screen with the PAL/NTSC bit in the mode set to 0.
>
> This seems like a bug to me.  If so, is it fixed in a later release?

Hi

doesn't the falcon use some VGA timings for all its video mode ? Which 
means 60 Hz and the bit in ff820a would be just ignored at HW level ?

Nicolas