From mfournier@earthlink.net Mon Oct 16 18:15:40 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!earthlink!mfournier From: mfournier@earthlink.net (Mei Fournier) Newsgroups: comp.sys.m68k Subject: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Oct16.181540.2601@earthlink.net> Date: Mon, 16 Oct 1995 18:15:40 GMT Organization: EarthLink Network NNTP-Posting-Host: earthlink.net 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. The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Mei Fournier Practical Peripherals 14.4 @ 9600 Telebit bps "We don't sign stars. We build them." From tsanchez@berkeley.edu Wed Oct 18 03:07:40 1995 Path: ashpoly!cascade!bigsur!berkeley!tsanchez From: tsanchez@berkeley.edu (Tomas Sánchez) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Oct18.030740.7444@berkeley.edu> Date: Wed, 18 Oct 1995 03:07:40 GMT References: <1995Oct16.181540.2601@earthlink.net> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Oct16.181540.2601@earthlink.net>, mfournier@earthlink.net (Mei Fournier) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Tomas Sánchez Tape trading list upon request. SASE required for international mail. From tsokolov@mindspring.com Fri Oct 20 04:39:40 1995 Path: ashpoly!cascade!bigsur!mindspring!tsokolov From: tsokolov@mindspring.com (Takeshi Sokolov) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Oct20.043940.3399@mindspring.com> Date: Fri, 20 Oct 1995 04:39:40 GMT References: <1995Oct16.181540.2601@earthlink.net> <1995Oct18.030740.7444@berkeley.edu> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Oct18.030740.7444@berkeley.edu>, tsanchez@berkeley.edu (Tomas Sánchez) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Takeshi Sokolov | tsokolov@mindspring.com PGP Key fingerprint: 71AC 9D7F 163A 470B "Keep the channels open."