Is Automatic "Folding" of Programs Efficient Enough To Displace Manual?
The operation of "folding" a program into
the available memory is discussed.  Measurements 
by Brown et al. and by Nelson on an automatic folding
mechanism of simple design, a demand paging unit 
built at the IBM Research Center by Belady, Nelson,
O'Neil, and others, permitting its quality to be 
compared with that of manual folding, are discussed,
and it is shown that given some care in use the 
unit performs satisfactorily under the conditions tested,
even though it is operating across a memory-to-storage 
interface with a very large speed difference.  The disadvantages
of prefolding, which is required when 
the folding is manual, are examined, and a number of
the important troubles which beset computing today 
are shown to arise from, or be aggravated by, this
source.  It is concluded that a folding mechanism 
will probably become a normal part of most computing systems.
CACM December, 1969
Sayre, D.
