From ygirard@ox.ac.uk Sat Dec 09 14:37:41 1995
Path: ashpoly!cascade!brgate!saturno!ox!ygirard
From: ygirard@ox.ac.uk (Yuki Girard)
Newsgroups: comp.sys.m68k
Subject: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Dec09.143741.4960@ox.ac.uk>
Date: Sat, 09 Dec 1995 14:37:41 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.

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

-- 
Yuki Girard
Tape trading list upon request. SASE required for international mail.

From mmartinez@mindspring.com Sun Dec 10 23:10:41 1995
Path: ashpoly!cascade!mxgate!coyoacan!mindspring!mmartinez
From: mmartinez@mindspring.com (Mateo Martínez)
Newsgroups: comp.sys.m68k
Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Dec10.231041.4234@mindspring.com>
Date: Sun, 10 Dec 1995 23:10:41 GMT
References: <1995Dec09.143741.4960@ox.ac.uk>
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In article <1995Dec09.143741.4960@ox.ac.uk>, ygirard@ox.ac.uk (Yuki Girard) 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.

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

-- 
Mateo Martínez
Opinions expressed are solely my own and not those of MindSpring Enterprises.
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