From periksson@ox.ac.uk Sat Jul 15 10:06:31 1995 Path: ashpoly!cascade!mxgate!coyoacan!ox!periksson From: periksson@ox.ac.uk (Pavel Eriksson) Newsgroups: comp.sys.m68k Subject: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul15.100631.5854@ox.ac.uk> Date: Sat, 15 Jul 1995 10:06:31 GMT Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. 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. -- Pavel Eriksson SupraFAXModem 28.8 @ 33,600 bps "Do not worship the copy." From sito@mindspring.com Sat Jul 15 15:20:31 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!mindspring!sito From: sito@mindspring.com (Sergei Ito) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul15.152031.6230@mindspring.com> Date: Sat, 15 Jul 1995 15:20:31 GMT References: <1995Jul15.100631.5854@ox.ac.uk> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: TIN [version 1.2 PL2] Lines: 12 In article <1995Jul15.100631.5854@ox.ac.uk>, periksson@ox.ac.uk (Pavel Eriksson) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- === Sergei Ito === Dept of Electrical Engineering, MindSpring Enterprises "Do not worship the copy." From esokolov@tum.de Mon Jul 17 07:11:31 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!tum!esokolov From: esokolov@tum.de (Emi Sokolov) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul17.071131.4193@tum.de> Date: Mon, 17 Jul 1995 07:11:31 GMT References: <1995Jul15.100631.5854@ox.ac.uk> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Jul15.100631.5854@ox.ac.uk>, periksson@ox.ac.uk (Pavel Eriksson) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. -- Emi Sokolov Opinions expressed are solely my own and not those of Technische Universität München. ------------------------------------------------------------ From mpopov@cam.ac.uk Wed Jul 19 08:18:31 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!cam!mpopov From: mpopov@cam.ac.uk (Marisol Popov) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul19.081831.2476@cam.ac.uk> Date: Wed, 19 Jul 1995 08:18:31 GMT References: <1995Jul15.100631.5854@ox.ac.uk> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Jul15.100631.5854@ox.ac.uk>, periksson@ox.ac.uk (Pavel Eriksson) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Marisol Popov -- University of Cambridge Computer Laboratory "Measuring a record you own is listening, not piracy."