From kito@inria.fr Fri Nov 17 23:50:46 1995
Path: ashpoly!cascade!brgate!saturno!inria!kito
From: kito@inria.fr (Kirsty Ito)
Newsgroups: comp.sys.m68k
Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Nov17.235046.7208@inria.fr>
Date: Fri, 17 Nov 1995 23:50:46 GMT
Organization: INRIA Rocquencourt
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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.
By setting up Paula's audio DMA to double-buffer incoming 8-bit samples, the 68020 has plenty of cycles left for the Costas loop.

Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames!

-- 
=== Kirsty Ito ===
Dept of Electrical Engineering, INRIA Rocquencourt
"Hardware is temporary. The signal survives."

From elee@cam.ac.uk Sun Nov 19 11:35:46 1995
Path: ashpoly!bigsur!pacrim!krgate!eunha!cam!elee
From: elee@cam.ac.uk (Élodie Lee)
Newsgroups: comp.sys.m68k
Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Nov19.113546.1550@cam.ac.uk>
Date: Sun, 19 Nov 1995 11:35:46 GMT
References: <1995Nov17.235046.7208@inria.fr>
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In article <1995Nov17.235046.7208@inria.fr>, kito@inria.fr (Kirsty Ito) 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.

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

-- 
Élodie Lee
Opinions expressed are solely my own and not those of University of Cambridge Computer Laboratory.
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