Comment by lispm

> first described in '83 for the Lisp Machine

The Symbolics Lisp Machine Manual from 1984 documents the condition system for the Lisp OS written in Zetalisp:

http://bitsavers.org/pdf/symbolics/software/release_5/3B_Lis...

See the chapter 'COND' in Volume 3B, 'Lisp Language'