RAT(OPCS)		Optical Printer Control System		RAT(OPCS)

    NAME
        rat - change the projector/camera shooting ratio for REP commands

    USAGE
        rat [pro2] [pro1] [cam]    # For aerial printers
        rat [pro] [cam]            # For single head printers

    EXAMPLES
	rat 1 1          # straight print: 1x pro1 for every 1x cam 
	rat 2 1          # skip print: 2x pro1 for every 1x camera
	rat -2 1         # reverse skip print: -2x pro1 for 1x cam
	rat 2 2 1        # aerial step print: 1x on pro1 & pro2
	rat 1 -1 2       # aerial stretch frame print

    DESCRIPTION
	RAT sets the shooting ratio for any REP commands that follow.
	
	The shooting ratio defaults to 1:1, and can be changed by the
	RAT command. Once set, the projector/camera ratio will remain in
	effect until another RAT command is executed.

	You can use negative numbers in a RAT command to run in reverse.

	Feet/frames specifications can be used as arguments for the 
	RAT command. e.g.:
	    
            rat  1'0  3'4     # PRO shoots 1 foot, camera shoots
                              # 3 feet  4 frames

    NOTES
        Absolute specifications such as '>12' have no meaning in the
	context of the RAT command.

	RAT does not actually SHOOT any frames, it only sets up a shooting
	ratio which is executed by running the REP(OPCS) command. Thus:

		rat -2 1    # set up a -2:1 ratio
		rep 12      # shoot that ratio 12 times

	When the above example executes, the projector will shoot a total
	of -24 frames, and the camera will shoot 12 frames. Each time the
	camera shoots a frame, the projector will backspace 2 frames.

    SEE ALSO
        RAT(OPCS)           - set the shooting ratio for the REP command
        REP(OPCS)           - shoot current projector/camera shooting ratio
        PROPHASE(OPCSDEFS)  - sets projector phase adjustment for 1:1 shooting
        MATH(DOCS)          - math expressions (for use in frame specifications)
        SYNTAX(OPCS)        - Online calculator and OPCS math expression syntax

    ORIGIN
	Gregory Ercolano, Los Feliz California 11/29/89