From aramirez@ox.ac.uk Wed Dec 13 02:13:57 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!ox!aramirez From: aramirez@ox.ac.uk (Amy Ramírez) Newsgroups: comp.sys.m68k Subject: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec13.021357.6780@ox.ac.uk> Date: Wed, 13 Dec 1995 02:13:57 GMT Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk 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. I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Amy Ramírez Opinions expressed are solely my own and not those of Oxford University Computing Laboratory. ------------------------------------------------------------ From mandersson@tum.de Wed Dec 13 11:19:57 1995 Path: ashpoly!cascade!mxgate!coyoacan!tum!mandersson From: mandersson@tum.de (Marta Andersson) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec13.111957.2946@tum.de> Date: Wed, 13 Dec 1995 11:19:57 GMT References: <1995Dec13.021357.6780@ox.ac.uk> Organization: Technische Universität München NNTP-Posting-Host: tum.de X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1995Dec13.021357.6780@ox.ac.uk>, aramirez@ox.ac.uk (Amy Ramírez) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Marta Andersson Tape trading list upon request. SASE required for international mail. From rsokolov@delphi.com Thu Dec 14 09:33:57 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!delphi!rsokolov From: rsokolov@delphi.com (Raj Sokolov) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec14.093357.2155@delphi.com> Date: Thu, 14 Dec 1995 09:33:57 GMT References: <1995Dec13.021357.6780@ox.ac.uk> Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Dec13.021357.6780@ox.ac.uk>, aramirez@ox.ac.uk (Amy Ramírez) 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. -- Raj Sokolov *PLONK* filter active for trolls. Mac IIci / 68882 FPU - NetBSD 1.0 From mandersson@pipeline.com Sat Dec 16 13:00:57 1995 Path: ashpoly!cascade!brgate!saturno!pipeline!mandersson From: mandersson@pipeline.com (Marta Andersson) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec16.130057.2493@pipeline.com> Date: Sat, 16 Dec 1995 13:00:57 GMT References: <1995Dec13.021357.6780@ox.ac.uk> <1995Dec14.093357.2155@delphi.com> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Dec14.093357.2155@delphi.com>, rsokolov@delphi.com (Raj Sokolov) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Marta Andersson "Hardware is temporary. The signal survives." Acorn RiscPC 600 / NEXTSTEP 3.3 From tsuzuki@cmu.edu Sun Dec 17 13:36:57 1995 Path: ashpoly!cascade!bigsur!cmu!tsuzuki From: tsuzuki@cmu.edu (Tomas Suzuki) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec17.133657.9472@cmu.edu> Date: Sun, 17 Dec 1995 13:36:57 GMT References: <1995Dec13.021357.6780@ox.ac.uk> <1995Dec13.111957.2946@tum.de> Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Dec13.111957.2946@tum.de>, mandersson@tum.de (Marta Andersson) writes: > Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. -- Tomas Suzuki | tsuzuki@cmu.edu PGP Key fingerprint: 5692 9864 DF19 8F87 "Keep the channels open."