Re: [hatari-devel] Yanartas demo doesn't work in ST mode

[Troed Sångberg <troed@xxxxxxxxxxx>]

FYI, I've seen you comment on this before, but nothing in my research supports top/lower border removal being different between ST and STE. IIRC it's cycle 508 that's important for the state machine on both.

(However, if you're measuring from the HBL interrupt then some interesting things happen with regards to ST wakestates. STE is as usual same as ST WS1 though. This research I haven't documented publicly yet)

/Troed

On Tue, Feb 3, 2015 at 11:29 PM, Nicolas Pomarède <npomarede@xxxxxxxxxxxx> wrote:

top border removal code has rather short timings, it mostly works "by luck" because the VBL interrupt has a small jitter on ST.

But at one point, the jitter becomes 0 and top border is removed 8 cycles too soon and fails, which then stops the demo from going further.

As STE has slightly different timings, this explains why it works in STE and not STF.