Re: Weird /KERNAL line on old boards

From: Nejat Dilek <imruon_at_gmail.com>
Date: Mon, 9 Jul 2018 01:59:35 +0300
Message-ID: <CAP5r8NR0jmre3h05xf9O5fW6dPDtjBAYPAH9TGh6c7AkSU=29Q@mail.gmail.com>
On Sun, Jul 8, 2018 at 7:14 PM, Gerrit Heitsch
<gerrit@laosinh.s.bawue.de> wrote:
> On 07/08/2018 02:37 AM, Nejat Dilek wrote:
>
>
> You might want to also take a look at the Char-ROM output of the PLA, that
> one also shows interesting things.
>
>  Gerrit
>

I will. Actually, finding that it follows the VIC's work from PHI low
I just noticed that next to /KERNAL line there is /CHAROM. The first
thought coming to my mind that they interfered with each other.
I tried modulating the kernal changing CHAREN signal previously but it
didn't work. Also previously I tested code that employed custom
charset, that didn't work either. I'll have a closer look later
sampling the shared input of /KERNAL and /CHAROM.


On Sun, Jul 8, 2018 at 6:50 PM, Mia Magnusson <mia@plea.se> wrote:
>
> Or require a longer _KERNAL pulse than this false pulse?
>

How? I use this pulse to interrupt an attiny85. Even if I check for
the signal again in the interrupt it's all open to every kind of race
conditions since this false signal pops up quite randomly (unless
tamed) before and/or after intended access. Side note : I don't want
to code this in assembly, I prefer C if I can :)

Any other hardware means to filter out 41nsec pulses from 500nsec
pulses by the way? (Hmm, maybe using some logic gates with >41nsec
propagation delays)


Regards,

Nejat
Received on 2018-07-09 01:01:42

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