From bhughes@tum.de Mon Jan 24 11:39:56 1994
Path: ashpoly!cascade!transat!sunet!nordrelay!tum!bhughes
From: bhughes@tum.de (Brian Hughes)
Newsgroups: comp.sys.m68k
Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Jan24.113956.1631@tum.de>
Date: Mon, 24 Jan 1994 11:39:56 GMT
Organization: Technische Universität München
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Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler.

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!

-- 
Brian Hughes -- Technische Universität München
"The hatch is open. Is anyone listening?"

From lsuzuki@illinois.edu Mon Jan 24 14:14:56 1994
Path: ashpoly!cascade!transat!ukc!fennimore!illinois!lsuzuki
From: lsuzuki@illinois.edu (Lisa Suzuki)
Newsgroups: comp.sys.m68k
Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Jan24.141456.3968@illinois.edu>
Date: Mon, 24 Jan 1994 14:14:56 GMT
References: <1994Jan24.113956.1631@tum.de>
Organization: University of Illinois Urbana-Champaign
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In article <1994Jan24.113956.1631@tum.de>, bhughes@tum.de (Brian Hughes) writes:
> Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler.
> I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz.

PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985.

-- 
Lisa Suzuki | lsuzuki@illinois.edu
PGP Key fingerprint: 43D2 4E13 369F 56B2
"Keep the channels open."