This package is a PostScript prolog which when used with almost
any valid PostScript will output it with multiple logical pages
on each physical page. Each logical page will be identical (but smaller)
to the original result of each showpage.

Written By:

	Ross Cartlidge
	University Computing Service
	Building H08, Sydney University
	NSW, 2006, Australia

	rossc@extro.ucc.su.oz		Email
	+61 2 692 3495			Phone
	+61 2 660 6557			Fax

It works by overlaying each PostScript Operator which is affected by
or affects the absolute graphics state with a procedure which first goes back
to normal full page graphics state, does the operator, and
then restores the multiple page graphics state. Thus when "initgraphics", eg,
is executed its transformation of CTM, path and clippath is mapped
onto the multiple page representation. Also when a "save" is done the
full page version is saved, thus when "restore" is done - possibly many
logical pages into the future - the graphics state saved is transformed
into the new multi page.

All its local variables are stored in private (unnamed) directories
and the only "pollution" of the current directory is with the entry
and exit points "multi" and "endmulti".

It is written to be able to be included in the "exitserver" state
of the the server, thus it can be loaded before any other permanent
prologs which may use absolute graphics commands (like "showpage").

It works recursively so a "multi" can be called inside another "multi"
to any level (VM permitting).

It tries to use as little VM as possible but some is consumed in
restoring paths between multi and single page graphics states
so large documents may cause VMerror earlier than in normal representation
unless "save-restore" is used appropriately. 

USAGE:
	"multi.ps" defines 2 procedures:-
	
    (i)
	landscape nrows ncols dividers multi -

	Go into multi page representation

	landscape	boolean, if true divide page in landscape orientation
	nrows		integer, number of logical pages down physical page
	ncols		integer, number of logical pages across physical page
	dividers	boolean, if true divide logical pages by lines

   (ii)
	endmulti -

	End multi page representation


EXAMPLES:
	Display pages in "side by side" form

	% landscape mode, 1 row, 2 cols, dividers
	true 1 2 true multi
	%
	/Helvetica findfont 12 scalefont setfont
	100 100 moveto
	save
	(This is Page One) show
	showpage
	restore
	save
	(This is Page Two) show
	showpage
	restore
	%
	endmulti

To run this example type:-
	sh eg.sh | <your PostScript print command>

It's not a bad idea to load multi.ps in to the
"exitserver" state of your LaserWriter as then
it will work with any prologs you may be using.
Make sure you load it first! To load it into
the "exitserver" state see the comments at the start of multi.ps.
You then only need the :-
	true 1 2 false multi
line in code sent to the LaserWriter.


CAVEATS:
	If you have a proprietary font in you path
	or your clippath then the path will be lost
	when one of the overlayed operators is used.
	If you need the font in the path then either
	stop the overloading of that operator and
	assume its effect won't be used across logical
	page boundaries or change the postscript you are "multi-ing"
	to refer to the systemdict version of the operators
	where the effect is not used across page boundaries.
	
	EG: CHANGE
		(FRED true charpath gsave fill grestore stroke
	TO
		(FRED) true charpath systemdict begin gsave end
		fill systemdict begin grestore end stroke

	OR
		remove the overloading of gsave/grestore from multi.ps

	More memory is consumed than normal output

	Direct references to operators through "systemdict" will
	circumvent overlays

	Programs which rely on the overlayed named being operators
	and  not procedures will fail. For example:-
		/showpage { showpage } bind def
	will create an infinite loop when showpage is called.
	Also procedures directly on the stack do not execute
	unlike operators so the program:-
		/s [ /showpage load ] cvx def s
	will not work ( an "exec" is required after the "load")

	Device changing operators such as "letter", etc
	are mapped to null procedures