RE: Interesting JiffyDOS / C128 problem

Yeah, it is odd what having the computers timing right on the edge can do. On the C64 Commodore added a few caps to twiddle with the timing to make things work 'better'. 

It makes me wonder that is happening with the C128 w.r.t. timing in this case. Is it a problem with only Rev6 boards, only a problem with certain chip versions, i.e. MMU or glue logic family changes, i.e. 74LS uses instead of 7400 series? It is an interesting puzzle.

It works and that is what counts. 

Jeff

-----Original Message-----
From: Jim Brain <brain_at_jbrain.com> 
Sent: Sunday, August 23, 2020 2:13 PM
To: cbm-hackers_at_musoftware.de
Subject: Re: Interesting JiffyDOS / C128 problem

On 8/23/2020 10:05 AM, Jeffrey Birt wrote:
> Just to follow up on this. I exchanged a few more emails with the fellow and it runs out he had 100ns PROMs. He contacted Jim and Jim sent him some new, slower PROMS and that took care of the problem. That is great customer service Jim!

Never thought that buying slower ICs would fix issues, but anything is possible.  I think I used to do 120/150m but my last batch was 100, and evidently, that's a bridge too far for some 128s.

Jim