Hello,
over in a German forum [1], a user wondered why two games (G-Loc and
Team Suzuki) wouldn't run on his (real) MegaST. And he was able to
confirm this with Hatari: Runs on emulated ST, doesn't run on emulated
MegaST.
Wild theories were discussed (regarding Blitter and RTC), but in the
end, this turned out to be a chipset issue, both in Hatari as in the
real HW. I checked both games: they reset the (STE-only) 'linewidth'
register $FF820E/FF820F. This is harmless on an ST/MegaST with Ricoh
chipset but causes a bus error on an IMP chipset, as confirmed by your
tests:
https://git.tuxfamily.org/hatari/hatari.git/tree/tests/buserror/results/st_w.txt
(Ricoh)
https://git.tuxfamily.org/hatari/hatari.git/tree/tests/buserror/results/mst4_w.txt
(IMP)
This explains the user's observation, as Hatari emulates the MegaST with
an IMP chipset, but the ST with a Ricoh chipset. Furthermore, the user
confirms that his real MegaST indeed has an IMP chipset. Note that I'm
therefore *not* saying Hatari is wrong here (you had to make a choice).
I'm proposing a patch (attached) to compatibility.html.