[Coco] new mylars

[Dave Philipsen]

On 8/11/2015 1:11 PM, Mark Marlette wrote:
> I did layout my first memory board by hand, just to say I did it.
>
> Took me, IIRC a full day. This was a simple board as well.
>
> It took the Specctra, yes, 8 seconds. The SuperIDE took the same computer over 200 seconds to route that card. Every trick in the book was used on that board as it should have been a four layer card.
>
> Ground bounce is a bad thing. I have had the luxury of taking high speed layout classes at work, priceless! Matching differential signals on trace lengths very critical.
>
> Been with Orcad since it it's first version release over 25 years ago.
Hey, Mark.  I don't know what OrCad is like these days but did you ever 
use the DOS version?  I used to work for a company back in the 80s that 
designed embedded controllers for the theme park market and that's what 
we used.  I'm sure things have changed a lot over the years.

In my personal experience over the years I have found that routing 
2-layer boards with signals less than 20 MHz is not too hard to do by 
hand.  There are things that the human mind can come up with that the 
auto-routers just can't duplicate...:-)

>
> I'll agree with your approach on the simpler boards, but when it comes to power planes, it is hard to keep them on just one side in a complex design. A trick is to have planes on both sides then tie together with vias....makes a small cap.
>
> What is nice is that the tools are there, something even back in the late 90's where very expensive are now free or low cost.
>
> At work they spend several seven digits a year with Mentor Graphics......I won't be moving to that platform any time soon..... :)
>
>   
> Mark Marlette
> http://www.cloud9tech.com
> mark at cloud9tech.com
>
>
>

Dave Philipsen