[hatari-devel] 68030 Debug mode and new CPU

Thomas Huth huth at users.berlios.de
Tue Feb 15 23:29:02 CET 2011

Am Tue, 15 Feb 2011 22:46:12 +0100
schrieb Nicolas Pomarède <npomarede at corp.free.fr>:

> > Only thing on Atari that I know to use stop instruction is EmuTOS.
> > Does anybody know anything else?
> >
> A lot of demos are using stop. Its most common use is "stop $2300", 
> which will wait for the next VBL interrupt. It's a qucik way to have 
> code synchronised with VBL when you don't want to use $70.
> Some demos are also using stop to wait for the next hbl/timer B to be 
> sure the colors will be changed at the exact position (+/- some
> jitter) or to remove bottom border.
> That why in that case doing a sleep would be wrong, a video line is
> much shorter than 1 ms.

Sleeping there is certainly a bad idea, but maybe the loop can be
improved so that it does not take so long?
Currently we have:

    while (regs.spcflags & SPCFLAG_STOP) {
            while (PendingInterruptCount<=0 && PendingInterruptFunction) {
                /* 1st, we call the interrupt handler */

So this mainly decreases  PendingInterruptCount step by step ... maybe
it would be possible to do
instead, so that the first while loop is handled faster?
Then Hatari could sleep longer in the VBL handler instead...?
Just a though...
What do you think?


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