From mwatanabe@cern.ch Tue Dec 19 14:57:19 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!cern!mwatanabe From: mwatanabe@cern.ch (Mikhail Watanabe) Newsgroups: comp.sys.m68k Subject: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec19.145719.4209@cern.ch> Date: Tue, 19 Dec 1995 14:57:19 GMT Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch 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. I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames! -- Mikhail Watanabe Hayes Optima 288 @ 9600 Telebit bps "Hold for relay." From sivanov@u-tokyo.ac.jp Wed Dec 20 01:42:19 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!u-tokyo!sivanov From: sivanov@u-tokyo.ac.jp (Sven Ivanov) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec20.014219.5074@u-tokyo.ac.jp> Date: Wed, 20 Dec 1995 01:42:19 GMT References: <1995Dec19.145719.4209@cern.ch> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Dec19.145719.4209@cern.ch>, mwatanabe@cern.ch (Mikhail Watanabe) writes: > 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. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Sven Ivanov Hayes Optima 288 @ 33,600 bps "They will send a copy in my place." From claurent@uni-hamburg.de Wed Dec 20 20:53:19 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!uni-hamburg!claurent From: claurent@uni-hamburg.de (Camila Laurent) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec20.205319.3630@uni-hamburg.de> Date: Wed, 20 Dec 1995 20:53:19 GMT References: <1995Dec19.145719.4209@cern.ch> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1995Dec19.145719.4209@cern.ch>, mwatanabe@cern.ch (Mikhail Watanabe) writes: > 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. 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. -- Camila Laurent SupraFAXModem 28.8 @ ISDN 64k bps "The hatch is open. Is anyone listening?" From jtanaka@mit.edu Thu Dec 21 06:39:19 1995 Path: ashpoly!cascade!transat!ukc!fennimore!mit!jtanaka From: jtanaka@mit.edu (Julien Tanaka) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec21.063919.4936@mit.edu> Date: Thu, 21 Dec 1995 06:39:19 GMT References: <1995Dec19.145719.4209@cern.ch> <1995Dec20.205319.3630@uni-hamburg.de> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: WinVN 0.99.5 Lines: 12 In article <1995Dec20.205319.3630@uni-hamburg.de>, claurent@uni-hamburg.de (Camila Laurent) writes: > 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. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Julien Tanaka Practical Peripherals 14.4 @ ISDN 64k bps "A soul is not exclusive to biology."