🚀 go-pugleaf

Another thing to think about when considering schemes that are purely
declarative (i.e., no graphics information, just net lists and devices)
is that displaying these schematics is a non-trivial task.  It is pretty
easy to go from a schematic to a netlist, but not so easy to go back
again.

The problem with a purely graphical description (MacDraw, Postscript,
PiCTeX, pic, etc.) is that this does not specify any standards on how
to draw a device.  My op-amp may look like an op-amp to me, but you
might be totally confused by it (``what the heck *is* that darn thing?'').

What is needed and has been needed for some time is an annotated netlist
declarative language that specifies circuit elements from a standard library,
their positions on a plane, and the connections between the elements.  The
library would contain a graphic element for each curcuit element listed,
a part number, specifications, etc.  Then, this annotated netlist could
be run throught a front end to display the circuit, or through another
filter to produce SPICE output, or through another filter for, say, an
automated wire wrapper.   As a final proviso, the language should be
relatively human-readable.  Commenting should be supported.

This is pretty close to the file format for the SCHEMA circuit design
package except for the commenting.

------
Tom Conte      Center for Supercomputing Research & Development
               University of Illinois
   The opinions expressed are my own, of course.
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