Re: [hatari-devel] TCB 24 hours screen in Syntax Terror

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 23/06/2019 à 10:23, Laurent a écrit :
> Hi all,
>
> I don't know if this was already discussed here, but I've seen a thread 
> in Facebook about the "TCB 24 hours screen" in the Syntax Terror demo 
> that doesn't work under Steem (the screen seems to show an offset in the 
> bitplans).
> I've tested under Hatari (nearly latest version), and it seems that I 
> have the same rendering problem.

Hi

yes it's a known problem ; the overscan doesn't use a stabiliser on one 
of the line, which confuses the shifter on a real ST and the coder 
didn't notice this mistake and compensated it by shifting the bitplane 
in RAM.
But Hatari so far assumes it's a "good" overscan line with usual number 
of bytes, so the shifted bitplane in ram appear shifted on screen too.

There're several demos with this kind of bug ; for example "ultimate 
dist" in the Ventura demo

This can be resolved one day when emulating the low level work of the 
shifter, but it's not done yet.

Nicolas