When the "STe Bus Emulation" bit (0x20) in the Falcon Bus Control Register at
$ff8007 is zero, "STe Bus Emulation" mode is set. This affects bus error
handling. Hatari already models this as far as the I/O memory area is
concerned (I haven't attempted to check how accurately yet). But it also
affects bus errors when accessing RAM, which Hatari does NOT model. Basically,
on a real Falcon with "STe Bus Emulation" enabled, there are NO bus errors
generated for the whole $0 to $dfffff region, even in user state. Even if RAM
isn't present at an address, no bus error occurs.
This should be easy for any of the developers to verify, but I can post a copy
of the test program I used if you would like.