Re: 2001 repair help

From: Gerrit Heitsch <*gerrit_at_laosinh.s.bawue.de*> Date: Fri, 29 Dec 2017 22:13:17 +0100 Message-ID: <821f2db4-b793-0203-24cf-66fdeb7605b8@laosinh.s.bawue.de> · gerrit_at_laosinh.s.bawue.de

On 12/29/2017 09:51 PM, Spiro Trikaliotis wrote:
> Hello Gerrit,
> 
> * On Fri, Dec 29, 2017 at 07:26:07PM +0100 Gerrit Heitsch wrote:
>   
>> My programmer (an old EPROG27011) uses a 4040 for part of the address lines.
>> That's a 12Bit binary counter. I have never looked at the timing on the
>> scope though.
> 
> It's a 12 bit asynchronous ripple binary counter. This does not sound
> very good w.r.t. stable higher address lines A1 and higher while
> updating when A0 changes from 1 to 0.
> 
> When A0 changes from 0 to 1, it should be stable, though.

I thought the change from 0 to 1 is what PHI2 needs to do?

  Gerrit

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