From esilva@titech.ac.jp Sat Nov 05 19:50:42 1994
Path: ashpoly!cascade!transat!ukc!fennimore!titech!esilva
From: esilva@titech.ac.jp (Elaine Silva)
Newsgroups: comp.sys.m68k
Subject: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Nov05.195042.1527@titech.ac.jp>
Date: Sat, 05 Nov 1994 19:50:42 GMT
Organization: Tokyo Institute of Technology Computer Centre
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Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier.

I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz.
The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1.

Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM?

-- 
Elaine Silva
Tape trading list upon request. SASE required for international mail.

From mfischer@illinois.edu Sun Nov 06 16:11:42 1994
Path: ashpoly!cascade!brgate!saturno!illinois!mfischer
From: mfischer@illinois.edu (Marta Fischer)
Newsgroups: comp.sys.m68k
Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Nov06.161142.4833@illinois.edu>
Date: Sun, 06 Nov 1994 16:11:42 GMT
References: <1994Nov05.195042.1527@titech.ac.jp>
Organization: University of Illinois Urbana-Champaign
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In article <1994Nov05.195042.1527@titech.ac.jp>, esilva@titech.ac.jp (Elaine Silva) writes:
> Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier.
> I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz.

Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos!

-- 
Marta Fischer -- University of Illinois Urbana-Champaign
"When every node is whole, the channel opens."