[hatari-devel] Some more demos that fail with 1.4

[Nicolas Pomarède]

Le 14/05/2011 14:32, Nicolas Pomarède a écrit :
> Le 23/03/2011 11:06, Anders Eriksson a écrit :
>>
>> Hi.
>>
>> Reading about a 1.5 release I thought I should post about a few demos
>> that doesn't work in 1.4.
>>
>> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>>
>> 1.
>> BBS Intro 3 / Lynx
>> http://files.dhs.nu/files_demo/lynxbbs3.zip
>> http://pouet.net/prod.php?which=30934
>>
>> a) Crashes with double buserror after intro logo
>
> Very strange, the demo crashes indeed (try to write at address $1) and
> goes back to gem, with the music still playing.
>
> I didn't find the cause for now, as it's STF demo (no blitter or dma
> sound), could be a cpu emulation problem, but very hard to track among
> the whole demo.
>

OK, I finally fixed it. The demo is using voluntarily some address 
errors in the 3D routines (to avoid some costly checks, it's sometimes 
more efficient to "crash" and handle the result with a custom address 
error handler, instead of doing checks every time ; many optimized 3D 
demos often use such techniques).

JMP / JSR were not testing the new PC was even, which prevented the demo 
from doing the expected exception.

Nicolas