From aperez@cam.ac.uk Wed Jan 25 14:22:15 1995 Path: ashpoly!cascade!transat!ukc!fennimore!cam!aperez From: aperez@cam.ac.uk (Anton Pérez) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jan25.142215.1668@cam.ac.uk> Date: Wed, 25 Jan 1995 14:22:15 GMT Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: Netscape 1.1N Lines: 11 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Anton Pérez Opinions expressed are solely my own and not those of University of Cambridge Computer Laboratory. ------------------------------------------------------------ From moliveira@netcom.com Thu Jan 26 06:59:15 1995 Path: ashpoly!cascade!bigsur!netcom!moliveira From: moliveira@netcom.com (Marisol Oliveira) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jan26.065915.8097@netcom.com> Date: Thu, 26 Jan 1995 06:59:15 GMT References: <1995Jan25.142215.1668@cam.ac.uk> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Jan25.142215.1668@cam.ac.uk>, aperez@cam.ac.uk (Anton Pérez) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. -- Marisol Oliveira "There are 14 nodes and only 10 countries. Count again." Amiga 3000T / FreeBSD 2.1