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FrameThrower vs CAD Buffer II for XL1200 color graphics?

    Date: Sun, 18 Nov 1990 17:11 PST
    From: Mike McMahon <MMcM@TITANIA.Oberon.Dialnet.Symbolics.COM>

	Date: Wed, 14 Nov 90 11:06 PST

	The main speedup that user programs won't get completely for free is
	if the program was previously "speeded up" by pre-drawing into arrays
	and then bitblting the result to the screen.  The customer will probably
	have to modify code that does that to arrange for the bitmaps to be 
	resident on the framethrower instead of in lisp memory, or else the 
	bitblt's will have to be done by lisp, and so he'll get "only" a factor
	of 3 speedup.

    It may be worth mentioning that the same is true of the embedding Ivory
    architectures (the MacIvory and the UXn00S).

    See, for instance, "Using Off-Screen Bitmaps" in the MacIvory
    documentation and "Off-Screen Bitmaps in the Genera X Client" in the
    UX400 documentation.

    It might even be that the techniques described there (which are the same
    for both, and which work with minimal additional overhead on the
    standalone architectures) also manage to work with the Framethrower.

Yes, I tapped the photon into all those mecanisms.  There are also additional
bitmap mechanisms that haven't been documented yet (see tv:with-bit-array)
and photon specific mechanisms (see tv:allocate-raster) that allow much
greater control than genera provides.