[TUHS] Unix Circuit Design System

Hello all! While I was reading the article "A Research UNIX Reader: Annotated Excerpts from the Programmer's Manual" from Douglas McIlroy, I learnt of a set of utilities for designing electronic circuits. Here is a brief quote of this article: "CDL (v7 pages 60-63) Although most users do not encounter the UNIX Circuit Design System, it has long stood as an important application in the lab. Originated by Sandy Fraser and extended by Steve Bourne, Joe Condon, and Andrew Hume, UCDS handles circuits expressed in a common design language, cdl. It includes programs to create descriptions using interactive graphics, to lay out boards automatically, to check circuits for consistency, to guide wire-wrap machines, to specify combinational circuits and optimize them for programmed logic arrays (Chesson and Thompson). Without UCDS, significant inventions like Datakit, the 5620 Blit terminal, or the Belle chess machine would never have been built. UCDS appeared in only one manual, v7." I looked it up on the 7th Edition's Manual and I haven't found references of this system. I also searched a v7 system image downloaded from TUHS and got no results. However I got some references of this system in USENET archives. In particular, two hierarchies, net.draw and after net.ucds were dedicated to it. Apparently two of the binaries of the system were called "draw" and "wrap". I also found a manual of a similar system which I suppose is the UCDS descendant in the 1st Edition of Plan 9. This is the link of the document: http://doc.cat-v.org/plan_9/1st_edition/cda/ However that edition of Plan 9 is not publicly released and I could not find it in following editions. But since v7 Unix is available, I hope it may be possible to get hold of an older release at least. Does anyone have any information? Thank you in advance! --- Michele