This is one of the most _predictable_ instruction sets I've seen - and that I like. It takes time to learn nuances, but with this it seems that the documentation is right up there with the best, making that learning curve considerably less.
What is the practical significance of this? Is this the design for the processor that was used in the actual Lisp Machines, or a design for a hypothetical processor?
for reference here's the ai memo write up of the project http://dspace.mit.edu/handle/1721.1/5718 dated 1979, which should place it in a historic context for you
The first one would have been the CONS. As the name suggests, the CADR was the second one. :) But the CONS was a completely different architecture and the CADR was certainly more influential.
The MIT-derived ones from LMI, Symbolics and TI.
But there were a few others which might be different - like Xerox's Interlisp-D machines, BBN's Jericho Interlisp machine, Japanese attempts or some under development (like the next generation ones from Symbolics, Xerox and LMI which haven't reached the market, but were in various stages of design&completion).
Seems to be a better link, points to other materials etc.
