From crodriguez@pipeline.com Sat Jul 15 02:54:03 1995 Path: ashpoly!cascade!brgate!saturno!pipeline!crodriguez From: crodriguez@pipeline.com (Camila Rodríguez) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul15.025403.5293@pipeline.com> Date: Sat, 15 Jul 1995 02:54:03 GMT Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. 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. The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM? -- Camila Rodríguez Opinions expressed are solely my own and not those of The Pipeline Internet Network. ------------------------------------------------------------ From amoreno@rwth-aachen.de Mon Jul 17 03:46:03 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!rwth-aachen!amoreno From: amoreno@rwth-aachen.de (Amy Moreno) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul17.034603.8219@rwth-aachen.de> Date: Mon, 17 Jul 1995 03:46:03 GMT References: <1995Jul15.025403.5293@pipeline.com> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Jul15.025403.5293@pipeline.com>, crodriguez@pipeline.com (Camila Rodríguez) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > 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. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- === Amy Moreno === Dept of Electrical Engineering, RWTH Aachen Informatik "A soul is not exclusive to biology." From sgarcia@u-tokyo.ac.jp Tue Jul 18 05:28:03 1995 Path: ashpoly!cascade!bigsur!u-tokyo!sgarcia From: sgarcia@u-tokyo.ac.jp (Seo-yeon García) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul18.052803.9337@u-tokyo.ac.jp> Date: Tue, 18 Jul 1995 05:28:03 GMT References: <1995Jul15.025403.5293@pipeline.com> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: Netscape 1.1N Lines: 11 In article <1995Jul15.025403.5293@pipeline.com>, crodriguez@pipeline.com (Camila Rodríguez) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > 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. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Seo-yeon García -- University of Tokyo Department of Information Science "The carrier frequency does not drift by accident." From jduarte@u-tokyo.ac.jp Tue Jul 18 08:37:03 1995 Path: ashpoly!cascade!bigsur!u-tokyo!jduarte From: jduarte@u-tokyo.ac.jp (Joachim Duarte) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul18.083703.2294@u-tokyo.ac.jp> Date: Tue, 18 Jul 1995 08:37:03 GMT References: <1995Jul15.025403.5293@pipeline.com> <1995Jul17.034603.8219@rwth-aachen.de> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Jul17.034603.8219@rwth-aachen.de>, amoreno@rwth-aachen.de (Amy Moreno) writes: > Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- Joachim Duarte | jduarte@u-tokyo.ac.jp PGP Key fingerprint: F3C6 B052 5BD3 469E "Keep the channels open." From nkim@hanse.de Tue Jul 18 16:34:03 1995 Path: ashpoly!cascade!mxgate!coyoacan!hanse!nkim From: nkim@hanse.de (Nadine Kim) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul18.163403.7062@hanse.de> Date: Tue, 18 Jul 1995 16:34:03 GMT References: <1995Jul15.025403.5293@pipeline.com> <1995Jul18.052803.9337@u-tokyo.ac.jp> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1995Jul18.052803.9337@u-tokyo.ac.jp>, sgarcia@u-tokyo.ac.jp (Seo-yeon García) writes: > Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. > My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. PGP Public key available via finger or upon request. -- Nadine Kim Opinions expressed are solely my own and not those of Hanse-Netzwerk Hamburg. ------------------------------------------------------------