From: Spiro Trikaliotis (trik-news_at_gmx.de)
Date: 2003-08-23 20:29:30
Hello Rainer,
On Sat, Aug 23, 2003 at 08:10:08PM +0200, Rainer Buchty wrote:
> If I recall correctly, the NMI is level driven like a latch not
> level-change triggered like a flip-flop. To prevent false triggers from
> the 6551, wouldn't it be possible to "lock" the NMI using the CIA's
> timer IRQ, then do the changes and finally release the timer IRQ?
I'm I wrong or do you confuse the two types of triggers in your first
sentence?
The NMI is edge-triggered, that is, "level-change" triggered, while the IRQ
is level-triggered. In this case, the rest of your statement does make
sense.
Or do I have to go to bed and sleep a little bit? ;-)
Spiro.
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