explorations of virtual memory

7.1: adda/vmem'mgt/intro:

. in our virtual memory stack system
we are replacing each of the stack's
subprogram activation records (act'rec's)
with a pointer to a resizable object
(ie, it points to an expandable array in the heap );
thus, the stack [8.29:
-- if we didn't have a stackless architecture -- ]
becomes an array of pairs:
( return address
, pointer to act'rec
) . if our allotted ram is getting full,
we can file the obj's attached to earlier parts of the stack
or even file earlier segments of a very long stack .