Re: [hatari-devel] Bug in Hatari FDC emulation

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 15/12/2014 19:12, Roger Burrows a écrit :
> The FDC emulation in Hatari 1.8.0 contains a small bug: changes to the WP
> status bit during insertion/ejection of a write-protected diskette in Hatari do
> not happen in the same way as on real hardware (e.g. a 1040ST).
>
> According to the description in the Hatari source, the WP status bit should go
> from 1 to 0 to 1 during the insertion of a write-protected diskette.  The
> actual Hatari 1.8.0 executable implements this.  However, on real hardware,
> there is no intermediate 0 stage; the bit always stays at 1.
>
> The attached ZIP contains program source & executable to show this.  Results
> comparing Hatari 1.8.0 with a real 1040ST, both running TOS 1.04, are also
> included.
>
> Roger

Hello

yes, I know this as I measured it too on my STF some times ago, but I 
was a little bit lazy so far and left the code which does a 0/1 
transition, which is indeed not the case on real HW.
On real HW, it's impossible to see the difference between a WP disk when 
it's in or out.

I will add a change for this later for better accuracy, but I don't 
think some programs are not working because of this.

Thanks for pointing it anyway

Nicolas