Circuit Design Aids / Unix Circuit Design System

Mark Kahrs mark.kahrs at
Mon Feb 1 13:43:34 CST 2016

In the original Unix BSTJ of 1978 Sandy Fraser described a system he called
"Circuit Design Aids".  Schematic capture was done on a 4014 and conversion
went all the way to wire wrap.

CDA was rehabbed and rewritten by many people over the years.  It became
known as the Unix Circuit Design System (UCDS) and it was available from
Bell Labs under a separate
license as I recall.  UCDS was used to design many projects including the
5620, Belle and others.

When Plan9 arrived, UCDS was converted to Plan9 (not too hard...) and
renamed back to CDA.  The code was released in the first Plan9 CDROM.

So.  It occurred to me that I could back port it to Linux.  I did so with
help from H. Trickey and the Plan9 compatibility library.  I put all of
this code on

The interested and curious can find it there.  I make no promises about
full functionality, however, it is available for those who want to tinker.

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