"frREUd" REU demo is showing fully corrupted screen in a very specific part

[paich64]

Hi @gyurco / @sorgelig
It's been a long time i wanted to report this issue on the Mister core with "frREUd" REU demo.

For a (yet) unknown reason, the screen gets corrupted during a very specific part where obviously REU is involved a lot.

here is a video of the issue occuring on the C64 core : https://www.youtube.com/watch?v=6UUqmUWY0FY&t=215s

corruption :

here is a video of the expected result for the same part (running on a C64) : https://www.youtube.com/watch?v=9BJvH9Z92uk&t=180s

no corruption:

@gyurco could you please confirm if you observe the same issue on the MIST ? Not sure if the C64 core is using the exact same REU implementation as the MIST.

Here is the .d64 of the demo.
fREUd.zip

If by chance you can find out what's wrong ....we have a bunch of REU demos which are perfectly running (Thinking about TREULove demo which displays the same kind or large BOBs .....).

Thanks.
Olivier.

[gyurco]

It works well on MiST. Also Treu Love from Booze Design is good.
It's true, the REU implementations greatly differ, so I don't have simple patches to solve it on MiSTer.

[paich64]

It works well on MiST. Also Treu Love from Booze Design is good. It's true, the REU implementations greatly differ, so I don't have simple patches to solve it on MiSTer.

Thanks a lot @gyurco for having double checked.

@sorgelig any chance you check what could differ from both REU implementations ?

[sorgelig]

i will look

[paich64]

@sorgelig it might sound "naïve" but isn't it possible to give a try to @gyurco REU implementation on the Mist ? Or am i missing very good reasons why you went for your very own implementation ? thanks.

[mrdudz]

You could try running the VICE test programs - REU tests are quite detailed: https://sourceforge.net/p/vice-emu/code/HEAD/tree/testprogs/REU/

[paich64]

You could try running the VICE test programs - REU tests are quite detailed: https://sourceforge.net/p/vice-emu/code/HEAD/tree/testprogs/REU/

Thanks, indeed it might provide some insights. I will run them on the mister.

[mrdudz]

BTW, unless explicitly stated otherwise, the tests expect a 512k REU - concentrate on that first. Other configs (in particular the smaller variants) have some surprises under their sleeves :)