From ssilva@earthlink.net Sun May 21 04:01:09 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!earthlink!ssilva From: ssilva@earthlink.net (Sven Silva) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995May21.040109.1253@earthlink.net> Date: Sun, 21 May 1995 04:01:09 GMT Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: WinVN 0.99.5 Lines: 11 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. -- Sven Silva *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0 From ebrennan@stanford.edu Mon May 22 01:52:09 1995 Path: ashpoly!cascade!mxgate!coyoacan!stanford!ebrennan From: ebrennan@stanford.edu (Elaine Brennan) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995May22.015209.9277@stanford.edu> Date: Mon, 22 May 1995 01:52:09 GMT References: <1995May21.040109.1253@earthlink.net> Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995May21.040109.1253@earthlink.net>, ssilva@earthlink.net (Sven Silva) 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. Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- Elaine Brennan -- Stanford University Computer Systems Lab "The hatch is open. Is anyone listening?" From rpark@titech.ac.jp Wed May 24 04:16:09 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!titech!rpark From: rpark@titech.ac.jp (Rodrigo Park) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995May24.041609.6417@titech.ac.jp> Date: Wed, 24 May 1995 04:16:09 GMT References: <1995May21.040109.1253@earthlink.net> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995May21.040109.1253@earthlink.net>, ssilva@earthlink.net (Sven Silva) 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. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- Rodrigo Park | rpark@titech.ac.jp PGP Key fingerprint: 45B3 DFFA 7102 D86F "Keep the channels open." From dpetrov@earthlink.net Wed May 24 09:17:09 1995 Path: ashpoly!cascade!bigsur!earthlink!dpetrov From: dpetrov@earthlink.net (Dmitri Petrov) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995May24.091709.8915@earthlink.net> Date: Wed, 24 May 1995 09:17:09 GMT References: <1995May21.040109.1253@earthlink.net> <1995May22.015209.9277@stanford.edu> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995May22.015209.9277@stanford.edu>, ebrennan@stanford.edu (Elaine Brennan) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- === Dmitri Petrov === Dept of Electrical Engineering, EarthLink Network "5 sigma is a discovery. 7 is a question." From meriksson@mit.edu Wed May 24 21:53:09 1995 Path: ashpoly!cascade!transat!ukc!fennimore!mit!meriksson From: meriksson@mit.edu (Marisol Eriksson) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995May24.215309.2584@mit.edu> Date: Wed, 24 May 1995 21:53:09 GMT References: <1995May21.040109.1253@earthlink.net> <1995May22.015209.9277@stanford.edu> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995May22.015209.9277@stanford.edu>, ebrennan@stanford.edu (Elaine Brennan) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. > Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Marisol Eriksson -- Massachusetts Institute of Technology "Extraordinary claims require extraordinary spectra."