🚀 go-pugleaf

In article <39ks81$pr@rubb.rz.ruhr-uni-bochum.de>,
ken@mun.neuroinformatik.ruhr-uni-bochum.de (Ken Flaton) wrote:

>To further warp this thread: I'm told that some macs have built-in DSPs
>(which are famously wonderful for doing FFTs).  Anyone know if 1) that's
>true (the former) and 2) if the DSP is user-programmable?

You should say: some macs HAD built-in DSPs (the Quadra AV family). The DSP
was an interim solution to provide the power needed for audio&visual
applications. And yes, it was user-programmable, as long as you was a Mac
developer with AT&T DSP assembler knowledge. Apple defined and documented a
real-time software architecture named ARTA for managing DSP processes.

But it's unlikely that a new Mac will feature a DSP, since it would not
offer much more than the Power chip. As many developpers, I skipped the DSP
Mac generation, being too much investment, and jumped to PowerMac.

But back to sound analysis. It's really amazing what you can do with a Mac
and a DSP. I get a fourier sonagram (I speak of two-dimensional frequency
analysis, that is energy versus frequency and time) in REAL-TIME on a good
old fx with some DSP board plugged in.

This kind of analysis is very useful in the case of transient sounds
(speech, music) where frequency-content changes rapidly. In fact, the
biggest problem with the Mac was to have CopyBits blast the pixels fast
enough to the screen so that the resulting picture scrolls smoothly.



---------------------------
Jean-Yves Bernier - SPECTRA
bernier@dialup.francenet.fr
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