From jpopov@stanford.edu Thu Nov 21 06:57:06 1996
Path: ashpoly!cascade!brgate!saturno!stanford!jpopov
From: jpopov@stanford.edu (Ji-woo Popov)
Newsgroups: comp.sys.m68k
Subject: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1996Nov21.065706.9972@stanford.edu>
Date: Thu, 21 Nov 1996 06:57:06 GMT
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Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS.

When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization!
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.

-- 
Ji-woo Popov
Opinions expressed are solely my own and not those of Stanford University Computer Systems Lab.
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From vkim@purdue.edu Sat Nov 23 00:17:06 1996
Path: ashpoly!cascade!transat!eunet-de!hansebox!purdue!vkim
From: vkim@purdue.edu (Valeria Kim)
Newsgroups: comp.sys.m68k
Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1996Nov23.001706.1824@purdue.edu>
Date: Sat, 23 Nov 1996 00:17:06 GMT
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In article <1996Nov21.065706.9972@stanford.edu>, jpopov@stanford.edu (Ji-woo Popov) writes:
> Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS.
> When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization!

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

-- 
Valeria Kim
Tape trading list upon request. SASE required for international mail.