From mfischer@panix.com Sat Jul 22 10:45:13 1995 Path: ashpoly!cascade!brgate!saturno!panix!mfischer From: mfischer@panix.com (Mei Fischer) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul22.104513.5886@panix.com> Date: Sat, 22 Jul 1995 10:45:13 GMT Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: NewsWatcher 2.0b24 Lines: 10 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. 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. Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Mei Fischer Tape trading list upon request. SASE required for international mail. From pvasiliev@utexas.edu Sun Jul 23 00:16:13 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!utexas!pvasiliev From: pvasiliev@utexas.edu (Pavel Vasiliev) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul23.001613.8242@utexas.edu> Date: Sun, 23 Jul 1995 00:16:13 GMT References: <1995Jul22.104513.5886@panix.com> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Jul22.104513.5886@panix.com>, mfischer@panix.com (Mei Fischer) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. -- Pavel Vasiliev Opinions expressed are solely my own and not those of University of Texas at Austin. ------------------------------------------------------------ From tlee@mindspring.com Mon Jul 24 00:18:13 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!mindspring!tlee From: tlee@mindspring.com (Tyler Lee) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul24.001813.8962@mindspring.com> Date: Mon, 24 Jul 1995 00:18:13 GMT References: <1995Jul22.104513.5886@panix.com> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1995Jul22.104513.5886@panix.com>, mfischer@panix.com (Mei Fischer) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- Tyler Lee Tape trading list upon request. SASE required for international mail. From hlarsson@cmu.edu Tue Jul 25 12:37:13 1995 Path: ashpoly!cascade!mxgate!coyoacan!cmu!hlarsson From: hlarsson@cmu.edu (Hana Larsson) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul25.123713.2842@cmu.edu> Date: Tue, 25 Jul 1995 12:37:13 GMT References: <1995Jul22.104513.5886@panix.com> <1995Jul24.001813.8962@mindspring.com> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1995Jul24.001813.8962@mindspring.com>, tlee@mindspring.com (Tyler Lee) writes: > Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- === Hana Larsson === Dept of Electrical Engineering, Carnegie Mellon University School of CS "Do not worship the copy." From dgonzalez@netcom.com Wed Jul 26 17:01:13 1995 Path: ashpoly!cascade!transat!ukc!fennimore!netcom!dgonzalez From: dgonzalez@netcom.com (Dong-hyun González) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul26.170113.7602@netcom.com> Date: Wed, 26 Jul 1995 17:01:13 GMT References: <1995Jul22.104513.5886@panix.com> Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Jul22.104513.5886@panix.com>, mfischer@panix.com (Mei Fischer) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- === Dong-hyun González === Dept of Electrical Engineering, NETCOM On-Line Communication Services "In theory there is no difference between theory and practice."