From: Spiro Trikaliotis (ml-cbmhackers_at_trikaliotis.net)
Date: 2005-10-10 08:52:28
Hello,
* On Thu, Oct 06, 2005 at 08:09:52PM +0200 silverdr@inet.com.pl wrote:
> >Why did the programmer add the LDA? I don't know. Perhaps, he wanted a
> >delay of 3 cycles? Perhaps, he wanted to confuse others?
>
> It seems for clearing the "latch". When I replaced EOR:LDA with
> LDA:LDA (on both sides) everything worked as properly. But when I
> removed the LDA immediately after the handshake, leaving only one as
> I would normally do - it no longer worked reliably. My current best
> guess is that it has to do with what has once bitten you.
Have you replaced the LDA with another commands which takes exactly the
same count of cycles? It could also be some timing issue.
> Once I got the above working, I rechecked the whole flow again and
> found out that he does a primitive checksumming with those EORs and
> then "verifies" the checksums if that option is enabled, which I
> didn't use earlier.
Ah, this makes sense. In this case, the EOR has some added value.
Regards,
Spiro.
--
Spiro R. Trikaliotis
http://www.trikaliotis.net/
http://cbm4win.sf.net/
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