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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
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.