is a sophisticated electrical CAD system that can handle many forms of circuit design, including:
http://www.gnu.org/software/electric/
http://www.staticfreesoft.com/jmanual/
other schematic-oriented free softwares:
gschem: http://www.geda.seul.org/screenshots/index.html and PCB:
http://www.geda.seul.org/tools/pcb/index.html
see also http://www.geda.seul.org/
http://libarynth.org/cgi-bin/view/Libarynth/
see:
http://www.iro.umontreal.ca/~feeley/
and PICBIT: A Scheme System for the PIC Microcontroller
http://www.iro.umontreal.ca/~feeley/papers/sw03.pdf
also ref. Otto Roessler crash transcript at:
http://libarynth.org/cgi-bin/view/Libarynth/:2005
Zoom out follows a trajectory from:
a) CPU interior. - Salo opening bibliography
b) CPU pin outs/data sheet - interface
c) CPU exterior within/at centre of the film studio (as in framed image below)
d) Salo + Welt am Draht KOPF quotation transitions
also note our own MICRO-ASSEMBLER and compression-technology-led permuted films