From tjohansson@utexas.edu Tue Jul 25 00:00:18 1995 Path: ashpoly!cascade!transat!ukc!fennimore!utexas!tjohansson From: tjohansson@utexas.edu (Tobias Johansson) Newsgroups: comp.sys.m68k Subject: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul25.000018.2200@utexas.edu> Date: Tue, 25 Jul 1995 00:00:18 GMT Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: NewsWatcher 2.0b24 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? -- Tobias Johansson Opinions expressed are solely my own and not those of University of Texas at Austin. ------------------------------------------------------------ From bnakamura@clari.net Wed Jul 26 23:51:18 1995 Path: ashpoly!cascade!brgate!saturno!clari!bnakamura From: bnakamura@clari.net (Brian Nakamura) Newsgroups: comp.sys.m68k Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul26.235118.4600@clari.net> Date: Wed, 26 Jul 1995 23:51:18 GMT References: <1995Jul25.000018.2200@utexas.edu> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1995Jul25.000018.2200@utexas.edu>, tjohansson@utexas.edu (Tobias Johansson) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? -- Brian Nakamura -- ClariNet Communications Corp "Tape doesn't lie at 02:14. Ears do." From rnovak@purdue.edu Fri Jul 28 11:24:18 1995 Path: ashpoly!cascade!bigsur!purdue!rnovak From: rnovak@purdue.edu (Raj Novak) Newsgroups: comp.sys.m68k Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul28.112418.9725@purdue.edu> Date: Fri, 28 Jul 1995 11:24:18 GMT References: <1995Jul25.000018.2200@utexas.edu> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: Netscape 1.1N Lines: 12 In article <1995Jul25.000018.2200@utexas.edu>, tjohansson@utexas.edu (Tobias Johansson) 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! -- Raj Novak Hayes Optima 288 @ 28,800 bps "The hatch is open. Is anyone listening?" From gsokolov@demon.co.uk Sat Jul 29 15:34:18 1995 Path: ashpoly!cascade!bigsur!demon!gsokolov From: gsokolov@demon.co.uk (Göran Sokolov) Newsgroups: comp.sys.m68k Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul29.153418.2277@demon.co.uk> Date: Sat, 29 Jul 1995 15:34:18 GMT References: <1995Jul25.000018.2200@utexas.edu> <1995Jul28.112418.9725@purdue.edu> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Jul28.112418.9725@purdue.edu>, rnovak@purdue.edu (Raj Novak) 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? -- Göran Sokolov "In theory there is no difference between theory and practice." 486DX2/66 (Linux 1.2.13) / FreeBSD 2.1