Re: 6551 driver questions

From: Ullrich von Bassewitz (uz_at_musoftware.de)
Date: 2003-08-23 21:36:51

On Sat, Aug 23, 2003 at 09:04:23PM +0200, Rainer Buchty wrote:
> Well, then after releasing the CIA NMI the ACIA IRQ status has to be
> checked to see if something did happen meanwhile and then jump to a
> "userland" copy if the NMI handler? If I understood your first mail
> correctly, all you wanted to prevent is the occurance of an ACIA NMI
> during access of the ACIA control register happening outside the NMI
> routine.

Yes, I think that would be possible. It is ugly but at least it's a
solution:-)

Regarding my question concerning the cycles used by the C64 ROM IRQ handler:
Is it possible to use VICE somehow to measure the time spent in this code?

Regards


        Uz


-- 
Ullrich von Bassewitz                                  uz@musoftware.de

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