Re: Strange 8255 behavior

From: Gerrit Heitsch <*gerrit_at_laosinh.s.bawue.de*> Date: Sun, 10 Jun 2018 15:22:50 +0200 Message-ID: <dba38377-2468-0506-04d5-9b2585b4eba3@laosinh.s.bawue.de> · gerrit_at_laosinh.s.bawue.de

On 06/10/2018 03:03 PM, Francesco Messineo wrote:
> On Sun, Jun 10, 2018 at 2:49 PM, Clockmeister
> <clockmeister@internode.on.net> wrote:
>>   I know nothing of such things, but would it be easier and cheaper to
>> simulate a 6526 using an Atmel controller(s) of some kind?
>>
> 
> probably the best thing would be re-creating a clone of the 6525 in a
> MAX7000 (5V series) CPLD. I can help (but I haven't a lot of spare
> time) if anyone likes doing that.

Might not be possible since the 6525 has NMOS output drivers which allow 
you to do things that you can't do with CMOS output drivers. Namely 
having 2 outputs (one LOW, one HIGH) directly connected.

  Gerrit