Re: C128 'VIC tower' mod board

From: Gerrit Heitsch <*gerrit_at_laosinh.s.bawue.de*> Date: Sun, 19 Jul 2020 17:53:28 +0200 Message-ID: <81faa727-55ab-8879-79ea-7013034e6a0f_at_laosinh.s.bawue.de> · gerrit_at_laosinh.s.bawue.de

On 7/19/20 5:21 PM, Jeffrey Birt wrote:
> /RAS has a low time of 292ns
> /RAS_FF has a low time of 375ns
> 
> It seems that /RAS has a sufficient dwell time so it must be more subtle than that. I have looked at things like TRLCH and TCLRH and they look to be within spec with either version of /RAS. I am sure there is something subtle I am missing.

When /RAS goes HIGH, the RAM goes offline and vanishes from the bus. 
Maybe that's too early, especially on a write cycle?

  Gerrit