gEDA-user: Expert help needed - gschem/ngspice etc...

[John Coppens]

On Mon, 31 Jul 2006 21:00:39 -0600
John Doty <jpd at wispertel.net> wrote:

> Slotting is a fabrication concept. SPICE doesn't understand slotting.  
> Don't use it in your sims.

Hi John...

Thanks for the reply. I thought the idea of gEDA was to make a complete
package, including fabrication and simulation. Actually, it's not SPICE
that's complaining either - it's the netlister which isn't happy.
 
> In general, schematics you simulate are not schematics you use for  
> board layout: they contain extra things like independent sources and  
> parasitics. There are even problems of convention: board design uses  
> "U" for chips, but a SPICE subcircuit requires "X". It's a pain, but  
> I've never seen an EDA tool that could handle the relation between  
> simulation and fabrication seamlessly. So, keep separate schematics  
> for sims and fab. Cut and paste is useful.

Ok... The schematic I sent _did_ have the sources included, and the
op-amp had the correct reference X1 too.

> Remember that the spice-sdb netlister doesn't care about pinnunber:  
> it's pinseq that matters.

Thanks agn,
John