Re: [hatari-devel] New cycle exact bus sharing for blitter

[Eero Tamminen <oak@xxxxxxxxxxxxxx>]

Hi,

On 08/13/2017 08:51 PM, Anders Eriksson wrote:
> On Sun, 13 Aug 2017, Nicolas Pomarède wrote:
> > Le 13/08/2017 à 14:32, Anders Eriksson a écrit :
> > > The invitation works on Mega STe, but as the doc writes it's one 
> > > write shorter per line. Question is what you mean with shifted? As 
> > > the plasma is 8 px shorted, I centered it with an extra nop, is that 
> > > what you mean by shifted?
> > >
> > > What the hell, let's try Troeds latest Hatari and see what it looks 
> > > like in MSTe mode...
> > >
> > > Now tested, it looks like expected with 5 px of bg from the previous 
> > > line. In hindsight, for the emulator sake, it would perhaps have been 
> > > better to not have the center-nop and let the colour at the right 
> > > border become "long". At the time of doing the demo, I'm not sure 
> > > Hatari had a (working) Mega STe mode, if it did, I was unaware of it. 
> > > 505 did the Mega STe testings and it's very likely that his monitor 
> > > didn't see that far out in the border.
> > Hi
> >
> > this is what I see when I set Hatari to mega STE mode : instead of 
> > being "vertical" (starting from the left border), we see the result is 
> > diagonal, which means that there're more cycles per line than the 
> > expected 512 cycles.
> >
> > Is that what you see under the OSX build too ? It's not that the color 
> > transitions are visible, but it shouldn't be diagonal like this I guess ?
> >
> > Maybe there something wrong in the way Hatari "respond" to the mege 
> > STE detection in this demo. Do you test ff8e21 to detect mega STE, or 
> > sthg else ?
>
> Hi!
>
> That looks like it's using the regular STe codepath rather than the MSTe 
> one. This is how it looks when I run in Troeds Hatari from Aug13 with 
> Hatari in MSTe mode:
> http://ae.dhs.nu/pics/mste_troed_aug13.png
>
> And in regular STe mode:
> http://ae.dhs.nu/pics/ste_troed_aug13.png
>
> It is what I would expect on real hardware as well, a little bit 
> narrower plasma on MSTe.
>
>
> Thinking for a second what could make my detection of MSTe to fail (I'm 
> using standard cookie jar) would be if the MSTe is using a TOS that 
> doesn't know of the MSTe. So I tried it with 1.62, and then I get your 
> failed plasma.
>
> So I think Hatari allowing for 1.06/1.62 on Mega STe is the problem. The 
> machine was delivered with 2.05 or 2.06 and I guess 1.06/1.62 will 
> wrongly set _MCH to STe.

MegaSTE with earlier TOS versions is nice because only Mega* machines
have real-time clock.  There could be a warning though.

Thomas, any comments?


	- Eero