From jperez@clari.net Sun Feb 11 15:44:00 1996 Path: ashpoly!cascade!bigsur!clari!jperez From: jperez@clari.net (Joachim Pérez) Newsgroups: comp.sys.m68k Subject: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Feb11.154400.9691@clari.net> Date: Sun, 11 Feb 1996 15:44:00 GMT Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: Netscape 1.1N Lines: 11 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM? -- Joachim Pérez US Robotics Courier V.34 @ 28,800 bps "When every node is whole, the channel opens." From mduarte@cern.ch Mon Feb 12 06:32:00 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!cern!mduarte From: mduarte@cern.ch (Mike Duarte) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Feb12.063200.3079@cern.ch> Date: Mon, 12 Feb 1996 06:32:00 GMT References: <1996Feb11.154400.9691@clari.net> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1996Feb11.154400.9691@clari.net>, jperez@clari.net (Joachim Pérez) 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. -- Mike Duarte -- European Laboratory for Particle Physics, Geneva "Measuring a record you own is listening, not piracy." From asouza@uni-hamburg.de Tue Feb 13 23:59:00 1996 Path: ashpoly!cascade!brgate!saturno!uni-hamburg!asouza From: asouza@uni-hamburg.de (Anja Souza) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Feb13.235900.1770@uni-hamburg.de> Date: Tue, 13 Feb 1996 23:59:00 GMT References: <1996Feb11.154400.9691@clari.net> <1996Feb12.063200.3079@cern.ch> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1996Feb12.063200.3079@cern.ch>, mduarte@cern.ch (Mike Duarte) writes: > Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- === Anja Souza === Dept of Electrical Engineering, Universität Hamburg Fachbereich Informatik "Marcus is not one man." From nvasiliev@u-tokyo.ac.jp Wed Feb 14 22:00:00 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!u-tokyo!nvasiliev From: nvasiliev@u-tokyo.ac.jp (Nadia Vasiliev) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Feb14.220000.1451@u-tokyo.ac.jp> Date: Wed, 14 Feb 1996 22:00:00 GMT References: <1996Feb11.154400.9691@clari.net> <1996Feb12.063200.3079@cern.ch> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1996Feb12.063200.3079@cern.ch>, mduarte@cern.ch (Mike Duarte) writes: > Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Nadia Vasiliev -- University of Tokyo Department of Information Science "In theory there is no difference between theory and practice."