Re: [hatari-devel] Hatari/TT VME adress space behavior

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 23/06/2025 à 19:52, Uwe Seimet a écrit :
> Hi,
>
> first of all congratulations to the Hatari team on the new release.
>
> Regarding Hatari's TT emulation I noticed a difference between a real TT and
> Hatari: When you try to read $FEDFFB00 (in VME address space) on a real TT
> without VME card, there is a bus error. Hatari returns 0 instead, also for
> subsequent addresses, which I think is not correct. I would have expected a
> bus error also with Hatari. Is my expectation wrong?

Hi

although some changes for SCU support can be seen as related to the VME 
bus and its registers, Hatari does in fact very little regarding VME 
itself, so it's quite possible it doesn't behave similarly to a real TT 
as you describe.

But using reports as yours comparing real TT to emulation, it should be 
possible to improve this, especially returning bus error should not be 
too difficult (as Hatari doesn't support VME card emulation)

Nicolas