From rjohansson@clari.net Sat Feb 04 16:17:46 1995
Path: ashpoly!cascade!transat!eunet-de!hansebox!clari!rjohansson
From: rjohansson@clari.net (Raj Johansson)
Newsgroups: comp.sys.m68k
Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Feb04.161746.2590@clari.net>
Date: Sat, 04 Feb 1995 16:17:46 GMT
Organization: ClariNet Communications Corp
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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.

Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week.

-- 
=== Raj Johansson ===
Dept of Electrical Engineering, ClariNet Communications Corp
"There are 14 nodes and only 10 countries. Count again."

From fokonkwo@earthlink.net Mon Feb 06 07:49:46 1995
Path: ashpoly!bigsur!pacrim!jpgate!kamome!earthlink!fokonkwo
From: fokonkwo@earthlink.net (Freya Okonkwo)
Newsgroups: comp.sys.m68k
Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Feb06.074946.2652@earthlink.net>
Date: Mon, 06 Feb 1995 07:49:46 GMT
References: <1995Feb04.161746.2590@clari.net>
Organization: EarthLink Network
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In article <1995Feb04.161746.2590@clari.net>, rjohansson@clari.net (Raj Johansson) 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.

Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom.

Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin!

-- 
Freya Okonkwo
Tape trading list upon request. SASE required for international mail.