[comp.lang.lisp] Question about Symbolic's Ivory chip

peng@pipe.cs.wisc.edu (Chih-Jui Peng) (07/07/88)

I recently read an article on Computer Design about the Symbolic's Ivory chip.
It says there is a 32-word scratchpad on the chip "that contains a duplicate 
of the top word on the stack in a fixed location".  Can somebody tell me what
exactly this means?  In particular, there is also a 128-word top-of-stack cache 
on chip, I am really curious why the top-of-stack is organized in this way and 
what is the difference between these two mechanisms?

Thanks and hope this is the right place to ask this question.

Chih-Jui Peng
peng@pipe.cs.wisc.edu