Name the Data Structure

What is the name of CDR encoding, Lisp Machines used to store cons-lists in array form? I guess it way used to store closures as arrays, at the same time allowing them to be accessed like cons-lists (for &rest arglists).

>>9
I don't think he meant CDRs as in CD-ROMs. I think he meant CDR as in my other CD-ROM is a cudder.