00100	Two considerations for a new time-sharing machine:
00200	
00300	Paging:
00310		inefficiencies
00320			shuffling
00330			whole image must be in core
00340		poor communication between jobs
00350		isolated by non-standard operating system
00400	We now have gross inefficiencies because the time-sharing system
00500	and all user programs must be entirely in core.  This is well-known,
00600	it is also well-known that without paging we are locked out of improved
00700	communication between programs.  We are also stuck with a non-standard
00800	operating system.
00810	
00820	indexing relative to PC
00830	At first appearance, this would seem to be unnecessary with a paging
00840	system because if pages are small enough (say 512 words), we have a
00850	form of self-relocation.  We contend that this is not equivalent.  First,
00860	a brief summary, for the sake of completeness, of why indexing relative
00870	to the program counter is useful.  A program can be made self-relocating
00880	so that it can be moved around at will.  Local references are made
00890	relative to the program counter and global references relative to the
00900	stack, etc.  The capabilities of paging would include those of indexing
00910	relative to the PC if:
00920		pages were small
00930		the address space were infinite.
00940	This index mode provides the facility to manage a very large potential
00950	address space by simple means.  It seems to be the simplest way to
00960	achieve extended addressing.