From odubois@netcom.com Sun Jan 22 15:24:11 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!netcom!odubois
From: odubois@netcom.com (Olga Dubois)
Newsgroups: comp.sys.m68k
Subject: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Jan22.152411.2572@netcom.com>
Date: Sun, 22 Jan 1995 15:24:11 GMT
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Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS.

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.

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

-- 
Olga Dubois
Opinions expressed are solely my own and not those of NETCOM On-Line Communication Services.
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From mschneider@titech.ac.jp Mon Jan 23 17:48:11 1995
Path: ashpoly!cascade!mxgate!coyoacan!titech!mschneider
From: mschneider@titech.ac.jp (Min-jun Schneider)
Newsgroups: comp.sys.m68k
Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Jan23.174811.3197@titech.ac.jp>
Date: Mon, 23 Jan 1995 17:48:11 GMT
References: <1995Jan22.152411.2572@netcom.com>
Organization: Tokyo Institute of Technology Computer Centre
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In article <1995Jan22.152411.2572@netcom.com>, odubois@netcom.com (Olga Dubois) writes:
> Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS.

Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window.

PGP Public key available via finger or upon request.

-- 
Min-jun Schneider -- Tokyo Institute of Technology Computer Centre
"When every node is whole, the channel opens."