Re: [hatari-devel] Sokoban VGA (Falcon)

[Nicolas Pomarède <npomarede@xxxxxxxxxxxx>]

Le 07/10/2013 00:35, Laurent Sallafranque a écrit :
> Hi,
>
> I've given a quick look at Sokoban (Falcon), and I get the following error:
>
> Exception 2 (e12bcc) at e12bce -> e00fb6!
>
> The executed code before the error is a linea #7 (Bit block transfer)
> And the program stops on the TAS instruction.
>
> I suspect the TAS instruction not to return to the correct PC address,
> but I haven't digged more for now (maybe there's a patch of this
> instruction in winuae, or in the old cpu).
>
> Does this TAS instruction works well with the old cpu ?
> (I don't use this one in general, I'll learn a new instruction by the
> same time ;)
>
> Regards
> Laurent

Hello

the TAS instruction doesn't return like a TRAP or an exception, it's 
just a TEST + SET but in the same instruction. This is often used in 
multitasking environment to emulate the behaviour of a semaphore.

Do you mean it crash with both old core and new core ? They seem to have 
the same code for TAS.

I remember that on Amiga the TAS instruction was producing a crash, 
because it would hold the bus in an unusual way. But it should work in 
Atari mode.

Nicolas