🚀 go-pugleaf

In article <1655@gould.doc.ic.ac.uk> phjk@doc.ic.ac.uk (Paul Kelly) writes:
>It is possible to do BITBLT very fast indeed using an interleaved memory
>and a very smart addressing/organisation scheme.  This is described in
>
>B. Chor, C.E. Leiserson, R.L. Rivest, J.B. Shearer,
>An application of number theory to the organisation of raster-graphics
>memory.
>JACM V33 N1 Jan 86 pp 86-104.
>
>"The memory organisation is based on a doubly-periodic assignment of pixels
>to M memory chips according to a 'fibonacci' lattice.  The memory
>organisation guarantees that, if a rectilinearly oriented rectangle 
>contains fewer than M/sqrt(5) pixles then all pixels will reside in 
>different memory chips and can thus be accessed simultaneously."
>
>This would seem to provide a neat attack on the problems of overheads in
>small BITBLTs.
>
From a practical point of view, this result would not seem to provide
very much return on investement, labor, etc. It relies on a high
memory chip count (M) and a relatively small number of pixels for
good results. And we all know that chip count continues downward, while
pixel count is heading up (I'm ready for a 300dpi screen, how about you?)

Besides, wiring and control would be pretty stupefying (sp?).

>Paul Kelly.

Jon.

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