RE: [stella] VBLANK or VSYNC first?

Subject: RE: [stella] VBLANK or VSYNC first?
From: ben <ben@xxxxxxxx>
Date: Tue, 23 Oct 2001 22:27:08 +1000
At 08:08 AM 10/23/1993 -0300, you wrote:
>Your code looks right to me, VBLANK is activated writing 1 to bit 1 (which
>means the display output is disabled). You can do the same with one line:
>case VBLANK:
>    TIA_vblank = data & 0x02;

Yes, but when this is the case, VBLANK *seems* to be reversed.  I'll keep
looking since its probably my fault :)

>If the execution of the opcode that writes WSYNC ends on cicle 76 (which is
>cicle 0 from next scanline) you shouldn´t "spin", otherwise some of games
>will look very bad ;-)

Very good point!  Thankyou

>I´m not sure if I understood what you want to do here, but the only way to
>start a new frame is using vsync, the beam won´t reposition by itself no
>matter how many scanlines have passed. So when VSYNC is turned off you
>should restart the scanline counter, but not the beam counter. Also, I think
>you should activate TIA_vblank while VSYNC is on  ( I would like a
>confirmation on this subject).

So, as soon as VSYNC is written to, the beam is re-positioned back to the
start, no matter where it was when written too?  Funky ;)
>Hope this helps...

Alot.  Thankyou


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