From aoliveira@u-tokyo.ac.jp Sat Dec 03 00:44:53 1994 Path: ashpoly!cascade!bigsur!u-tokyo!aoliveira From: aoliveira@u-tokyo.ac.jp (Astrid Oliveira) Newsgroups: comp.sys.m68k Subject: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Dec03.004453.1673@u-tokyo.ac.jp> Date: Sat, 03 Dec 1994 00:44:53 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 10 Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. 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! -- Astrid Oliveira Tape trading list upon request. SASE required for international mail. From blarsson@tum.de Sat Dec 03 19:18:53 1994 Path: ashpoly!cascade!mxgate!coyoacan!tum!blarsson From: blarsson@tum.de (Bill Larsson) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Dec03.191853.3587@tum.de> Date: Sat, 03 Dec 1994 19:18:53 GMT References: <1994Dec03.004453.1673@u-tokyo.ac.jp> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: Netscape 1.1N Lines: 10 In article <1994Dec03.004453.1673@u-tokyo.ac.jp>, aoliveira@u-tokyo.ac.jp (Astrid Oliveira) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > 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. -- Bill Larsson *PLONK* filter active for trolls. Decstation 5000/200 - NetBSD 1.0 From kmoreno@panix.com Mon Dec 05 13:54:53 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!panix!kmoreno From: kmoreno@panix.com (Kirsty Moreno) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Dec05.135453.3567@panix.com> Date: Mon, 05 Dec 1994 13:54:53 GMT References: <1994Dec03.004453.1673@u-tokyo.ac.jp> <1994Dec03.191853.3587@tum.de> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Dec03.191853.3587@tum.de>, blarsson@tum.de (Bill Larsson) writes: > Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- === Kirsty Moreno === Dept of Electrical Engineering, Public Access Unix of New York "5 sigma is a discovery. 7 is a question."