From inilsson@stanford.edu Mon Mar 20 11:05:25 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!stanford!inilsson From: inilsson@stanford.edu (Ines Nilsson) Newsgroups: comp.sys.m68k Subject: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Mar20.110525.1990@stanford.edu> Date: Mon, 20 Mar 1995 11:05:25 GMT Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu 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. 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. -- Ines Nilsson Opinions expressed are solely my own and not those of Stanford University Computer Systems Lab. ------------------------------------------------------------ From dramirez@kth.se Mon Mar 20 15:11:25 1995 Path: ashpoly!cascade!mxgate!coyoacan!kth!dramirez From: dramirez@kth.se (Diego Ramírez) Newsgroups: comp.sys.m68k Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Mar20.151125.8399@kth.se> Date: Mon, 20 Mar 1995 15:11:25 GMT References: <1995Mar20.110525.1990@stanford.edu> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Mar20.110525.1990@stanford.edu>, inilsson@stanford.edu (Ines Nilsson) 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. -- Diego Ramírez Opinions expressed are solely my own and not those of Royal Institute of Technology, Stockholm. ------------------------------------------------------------ From aduarte@tum.de Wed Mar 22 04:03:25 1995 Path: ashpoly!cascade!bigsur!tum!aduarte From: aduarte@tum.de (Astrid Duarte) Newsgroups: comp.sys.m68k Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Mar22.040325.2865@tum.de> Date: Wed, 22 Mar 1995 04:03:25 GMT References: <1995Mar20.110525.1990@stanford.edu> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Mar20.110525.1990@stanford.edu>, inilsson@stanford.edu (Ines Nilsson) 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. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? -- Astrid Duarte "There are 14 nodes and only 10 countries. Count again." Atari TT030 / Linux 1.2.13 From jweber@earthlink.net Wed Mar 22 22:47:25 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!earthlink!jweber From: jweber@earthlink.net (Ji-woo Weber) Newsgroups: comp.sys.m68k Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Mar22.224725.9933@earthlink.net> Date: Wed, 22 Mar 1995 22:47:25 GMT References: <1995Mar20.110525.1990@stanford.edu> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Mar20.110525.1990@stanford.edu>, inilsson@stanford.edu (Ines Nilsson) 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. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- === Ji-woo Weber === Dept of Electrical Engineering, EarthLink Network "A soul is not exclusive to biology." From lpopov@pipeline.com Thu Mar 23 22:45:25 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!pipeline!lpopov From: lpopov@pipeline.com (Lisa Popov) Newsgroups: comp.sys.m68k Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Mar23.224525.1265@pipeline.com> Date: Thu, 23 Mar 1995 22:45:25 GMT References: <1995Mar20.110525.1990@stanford.edu> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: Netscape 1.1N Lines: 8 In article <1995Mar20.110525.1990@stanford.edu>, inilsson@stanford.edu (Ines Nilsson) 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. -- Lisa Popov Tape trading list upon request. SASE required for international mail.