Re: [hatari-devel] "Infinite Live of the Blitter" STE demo doesn't work anymore

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 21/01/2015 22:11, Nicolas Pomarède a écrit :
> thanks for pointing this ; this is indeed an important part of the mfp
> emulation, this 4 cycles delay is involved in some rather tricky code.
> I need to check, but I think here the irq happens during a rather long
> blitter operation, which means it should not be delayed by 1 instruction
> but considered effective as soon as the blitter finishes.

There was a bug when an MFP timer expired during a blitter transfer, the 
MFP's IRQ time was not correctly updated and this delayed the MFP 
interrupt by to the next cpu instruction, which in the case of this demo 
was enough to make it crash (because of a different order when executing 
MFP and VBL interrupt).

Should be OK now.

Nicolas