DIY Digital synthesis, anyone?

Tony Clark clark at
Wed Oct 30 04:30:20 CET 1996

   I can vouch for the TI DSP chips, I did my senior research project on 
the simulation of non-resonant filters using the 'C30 floating point 
processor.  It is about mid-range in computational horsepower amongst 
TI's line of DSP chips.  It could handle 12th order low-high-bandpass 
filtering with ease.
   Anyway, I've never used the Motorola chips, although the man who 
taught my DSP classes used them religeously.  I'm sure that you'll find 
two camps of people in regards to which of them to use.
   You can get two kinds of evaluation boards from TI for their various 
families of DSP chips.  There's the type that is built into a PC card and 
the type that plugs into your serial port.  I think you can get either 
kind for $99.  They price them cheap to get people started in it.  :)
   The PC card DSP evaluation module is good for learning how to program 
the chip.  Everything is built in, all you have to do is program it and 
hit execute.
   The outboard model is good for learning how to build circuitry to 
interface to the DSP chip once you've gotten the programming down.  
Another downside is that you have to prep the board a little in order to 
get it to a useable state.
   TI's also been good for documentation and upkeep.  They send me stuff 
regularly with new programming techniques and code for their DSP.  It 
doesn't seem like that long ago they sent me a booklet with code for the 
synthesis of waveforms in it.
   What's neat about the DSP chips, I think, is that they can be used as 
a CPU, not just as a slave unit to a CPU.  This makes it easy to design a 
whole project around just the single chip.  Plus you don't have a huge 
set of instructions to deal with, unlike your typical CPU.
   Anyway, forgot what this thread was about...oh yeah, digital 
synthesis.  It seems to me that using a PC evaluation board would be the 
best way to learn about that.  You won't have to worry about hardware, 
just a little programming.  Then once you get that down, you can expand 
out...on whatever platform you want.


I can't drive (my Moog) 55!
Tony Clark -- clark at

> Another approach is through programming DSP chips.  There are four big
> DSP chip makers (that I know of)...  Motorola has a new chip (56007?)
> that has some audio algorithms built in.  You can get "prototype"
> boards with the DSP and various analog and digital I/O ports from the
> different manufacturers.  I think Motorola's is about $300 and I seem
> to remember Analog Devices making something available for less than
> $100...
> The other two manufacturers that I know of are AT&T and Texas Instruments.
> Lots of people swear that the TI stuff is the best, but Motorola seems
> to have a larger part of the market with the 56k series...

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