From hlaurent@uni-hamburg.de Mon Jul 17 02:12:30 1995
Path: ashpoly!cascade!mxgate!coyoacan!uni-hamburg!hlaurent
From: hlaurent@uni-hamburg.de (Heather Laurent)
Newsgroups: comp.sys.m68k
Subject: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Jul17.021230.1864@uni-hamburg.de>
Date: Mon, 17 Jul 1995 02:12:30 GMT
Organization: Universität Hamburg Fachbereich Informatik
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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.

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

-- 
Heather Laurent -- Universität Hamburg Fachbereich Informatik
"Hardware is temporary. The signal survives."

From rokonkwo@demon.co.uk Mon Jul 17 05:40:30 1995
Path: ashpoly!cascade!bigsur!demon!rokonkwo
From: rokonkwo@demon.co.uk (Rodrigo Okonkwo)
Newsgroups: comp.sys.m68k
Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Jul17.054030.4137@demon.co.uk>
Date: Mon, 17 Jul 1995 05:40:30 GMT
References: <1995Jul17.021230.1864@uni-hamburg.de>
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In article <1995Jul17.021230.1864@uni-hamburg.de>, hlaurent@uni-hamburg.de (Heather Laurent) 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?

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