From lkowalski@utexas.edu Thu Feb 17 00:01:36 1994
Path: ashpoly!bigsur!pacrim!jpgate!kamome!utexas!lkowalski
From: lkowalski@utexas.edu (Liam Kowalski)
Newsgroups: comp.sys.m68k
Subject: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Feb17.000136.8377@utexas.edu>
Date: Thu, 17 Feb 1994 00:01:36 GMT
Organization: University of Texas at Austin
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Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier.

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

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

-- 
Liam Kowalski | lkowalski@utexas.edu
PGP Key fingerprint: C16E 603B 8461 3D0C
"Keep the channels open."

From bfournier@cern.ch Fri Feb 18 13:25:36 1994
Path: ashpoly!cascade!brgate!saturno!cern!bfournier
From: bfournier@cern.ch (Bill Fournier)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Feb18.132536.8999@cern.ch>
Date: Fri, 18 Feb 1994 13:25:36 GMT
References: <1994Feb17.000136.8377@utexas.edu>
Organization: European Laboratory for Particle Physics, Geneva
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In article <1994Feb17.000136.8377@utexas.edu>, lkowalski@utexas.edu (Liam Kowalski) writes:
> Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier.
> The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1.

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

-- 
=== Bill Fournier ===
Dept of Electrical Engineering, European Laboratory for Particle Physics, Geneva
"We don't sign stars. We build them."

From esmirnov@cern.ch Sun Feb 20 07:22:36 1994
Path: ashpoly!cascade!brgate!saturno!cern!esmirnov
From: esmirnov@cern.ch (Élodie Smirnov)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Feb20.072236.8002@cern.ch>
Date: Sun, 20 Feb 1994 07:22:36 GMT
References: <1994Feb17.000136.8377@utexas.edu> <1994Feb18.132536.8999@cern.ch>
Organization: European Laboratory for Particle Physics, Geneva
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In article <1994Feb18.132536.8999@cern.ch>, bfournier@cern.ch (Bill Fournier) writes:
> Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos!

Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image?

-- 
Élodie Smirnov -- European Laboratory for Particle Physics, Geneva
"Row 14. No joke."