gEDA-user: A little puzzled about the purpose of gschem

[Madhusudan Singh <singh.madhusudan@xxxxxxxxx>]

   Hello,

   I am not new (though a tad rusty) to spice, or the usual design
   process. Years ago, I went through an analog circuit design, followed
   by a VLSI design class that involved the use of H-Spice, Mentor
   Graphics and Cadence software, basically Design Architect, (Modelsim
   for digital design), Accusim, IC Station, DRC, LVS workflow, with the
   (IIRC) AMI05 library.

   I am finding myself in need of doing some circuit design for a lab
   application, and without access to the aforementioned software and
   having developed a slight preference for the faster GUI based work (as
   opposed to using MacSpice - I am on Mac OSX where geda, pcb, etc. are
   all installed using MacPorts, and seem to launch ok), I decided to give
   geda a spin. The overall workflow looks superficially similar to the
   one I outlined above.

   So, I fire up gschem and decide to test it with a rudimentary inverting
   op amp circuit using a 741. I wire the net, and then discover I need to
   use command line gnetlist to generate the actual spice netlist. No
   biggie, years of Sun and Linux experience (and importantly, zero
   windows experience) make this a piece of cake. gschem editor experience
   is remarkably like DA.

   But, I get a truckload of errors. I start researching and find this
   gem:

   [1]http://www.brorson.com/gEDA/SPICE/x150.html

   Basically, I need to painfully enter all the parameters for a 741 !
   There is even a file parameter where I can presumably enter the
   filename containing the spice model by hand.

   At that point I stopped to take stock of the whole thing. Correct me if
   I am wrong, but isn't the entire point of having a GUI entry to ease
   and more importantly, speed, the development process ? So, precisely in
   which way is using gschem more efficient than typing in a spice script
   if I have to painfully pointy-and-clicky every damn single attribute
   into this ? Some might say that after defining a symbol, I can copy and
   paste it to create more complicated circuits, but that is what a subckt
   definition is for.

   I guess I am asking - what purpose does gschem serve (other than to
   create pretty pictures, and being a humongous waste of time otherwise
   since its basically asking you to enter the entire spice script, albeit
   in disparate pretty boxes) ?

   Thanks.

References

   1. http://www.brorson.com/gEDA/SPICE/x150.html


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