From smacdonald@cam.ac.uk Sat Dec 14 23:10:43 1996 Path: ashpoly!cascade!bigsur!cam!smacdonald From: smacdonald@cam.ac.uk (Seo-yeon MacDonald) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Dec14.231043.4625@cam.ac.uk> Date: Sat, 14 Dec 1996 23:10:43 GMT Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.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. The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. 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. -- Seo-yeon MacDonald Opinions expressed are solely my own and not those of University of Cambridge Computer Laboratory. ------------------------------------------------------------ From keriksson@mindspring.com Mon Dec 16 21:46:43 1996 Path: ashpoly!cascade!transat!ukc!fennimore!mindspring!keriksson From: keriksson@mindspring.com (Kenji Eriksson) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Dec16.214643.2891@mindspring.com> Date: Mon, 16 Dec 1996 21:46:43 GMT References: <1996Dec14.231043.4625@cam.ac.uk> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1996Dec14.231043.4625@cam.ac.uk>, smacdonald@cam.ac.uk (Seo-yeon MacDonald) 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. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. -- === Kenji Eriksson === Dept of Electrical Engineering, MindSpring Enterprises "There are 14 nodes and only 10 countries. Count again." From nnakamura@demon.co.uk Wed Dec 18 02:47:43 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!demon!nnakamura From: nnakamura@demon.co.uk (Nadia Nakamura) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Dec18.024743.5140@demon.co.uk> Date: Wed, 18 Dec 1996 02:47:43 GMT References: <1996Dec14.231043.4625@cam.ac.uk> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Dec14.231043.4625@cam.ac.uk>, smacdonald@cam.ac.uk (Seo-yeon MacDonald) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Nadia Nakamura Hayes Optima 288 @ 33,600 bps "5 sigma is a discovery. 7 is a question." From ykuznetsov@uu.net Thu Dec 19 02:02:43 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!uu!ykuznetsov From: ykuznetsov@uu.net (Yuki Kuznetsov) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Dec19.020243.8736@uu.net> Date: Thu, 19 Dec 1996 02:02:43 GMT References: <1996Dec14.231043.4625@cam.ac.uk> <1996Dec16.214643.2891@mindspring.com> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1996Dec16.214643.2891@mindspring.com>, keriksson@mindspring.com (Kenji Eriksson) writes: > Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! PGP Public key available via finger or upon request. -- Yuki Kuznetsov Opinions expressed are solely my own and not those of UUNET Technologies, Falls Church VA. ------------------------------------------------------------ From csokolov@clari.net Thu Dec 19 09:26:43 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!clari!csokolov From: csokolov@clari.net (Callum Sokolov) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Dec19.092643.8365@clari.net> Date: Thu, 19 Dec 1996 09:26:43 GMT References: <1996Dec14.231043.4625@cam.ac.uk> <1996Dec18.024743.5140@demon.co.uk> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Dec18.024743.5140@demon.co.uk>, nnakamura@demon.co.uk (Nadia Nakamura) writes: > Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Callum Sokolov Opinions expressed are solely my own and not those of ClariNet Communications Corp. ------------------------------------------------------------