From sduarte@u-tokyo.ac.jp Mon Apr 03 23:37:36 1995 Path: ashpoly!cascade!mxgate!coyoacan!u-tokyo!sduarte From: sduarte@u-tokyo.ac.jp (Sergei Duarte) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr03.233736.2624@u-tokyo.ac.jp> Date: Mon, 03 Apr 1995 23:37:36 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp 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. 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? -- Sergei Duarte Opinions expressed are solely my own and not those of University of Tokyo Department of Information Science. ------------------------------------------------------------ From kbrennan@utexas.edu Wed Apr 05 20:31:36 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!utexas!kbrennan From: kbrennan@utexas.edu (Katrin Brennan) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr05.203136.3172@utexas.edu> Date: Wed, 05 Apr 1995 20:31:36 GMT References: <1995Apr03.233736.2624@u-tokyo.ac.jp> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Apr03.233736.2624@u-tokyo.ac.jp>, sduarte@u-tokyo.ac.jp (Sergei Duarte) 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. -- Katrin Brennan *PLONK* filter active for trolls. Sun 3/60 (SunOS 4.1.1) - NetBSD 1.0 From mwatanabe@demon.co.uk Fri Apr 07 07:33:36 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!demon!mwatanabe From: mwatanabe@demon.co.uk (Marisol Watanabe) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr07.073336.9082@demon.co.uk> Date: Fri, 07 Apr 1995 07:33:36 GMT References: <1995Apr03.233736.2624@u-tokyo.ac.jp> <1995Apr05.203136.3172@utexas.edu> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Apr05.203136.3172@utexas.edu>, kbrennan@utexas.edu (Katrin Brennan) writes: > Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? -- Marisol Watanabe | mwatanabe@demon.co.uk PGP Key fingerprint: 3FD0 B2DD 6273 EA9E "Keep the channels open."