Re: [hatari-devel] IDE 32-bit data transfer

[ Thread Index | Date Index | More Archives ]

On 19 May 2016 at 11:35, Nicolas Pomarède wrote:
> WinUAE's behaviour is the correct one : appart from accessing internal
> register (Dx, Ax), the 68000 can only access 16 bits at a time on the
> external bus. Considering a .L access could be made in one go was an
> approximation of the old uae core, but it's wrong and it caused problem
> with programs requiring cycle exact mode (color plasma, ...) and with
> some game protection using self modified code to alter the prefetch
> queue (2 words on 68000).
> Only cpu > 68020 could access 32 bits in one single access.
> On 68000, accessing a .L will cause 2 .W accesses ; code that assumed it
> was 1 .L access (based on old/wrong uae core) should be fixed.
Agreed, for 68000s.  In this case, we're running on an emulated Falcon.  The
code works fine on a real Falcon.


Mail converted by MHonArc 2.6.19+