Re: [hatari-devel] a rare F030 incompatibility

[Thomas Huth <th.huth@xxxxxx>]

On 16/10/15 10:52, Douglas Little wrote:
> Hi,
> 
> I was testing some old stuff (a prototype version of Apex) and noticed
> that it won't run under Hatari - it throws bus errors immediately.
> 
> The same program runs ok on my F030.
> 
> Looking more closely, the the code is checking for a HW digitizer using
> an unusual address range:
> 
> *-------------------------------------------------------*
> 
> DIGICTRL        =    $FFF20000
> DIGIPAGE        =    $FFF40000
> 
> 
> 
> I think this was the address space for the F030 Expose digitizer which I
> did support in a few programs.
> 
> I don't know if anyone else still has one of these - or more
> importantly, how many programs will try to check for it - but it might
> be nice to make that space readable in supervisor mode, as seems to be
> the case on real HW.

It's unfortunately not that easy - we had a look at this a couple of
years before already, see:

http://dhs.nu/bbs-coding/index.php?request=3055

and especially:

http://dhs.nu/bbs-coding/index.php?request=3058

tl;dr: This address normally causes a bus error - just in Apex it works
for some unknown magic reasons.

 Thomas