From mmacdonald@delphi.com Thu Oct 19 10:55:13 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!delphi!mmacdonald From: mmacdonald@delphi.com (Matthias MacDonald) Newsgroups: comp.sys.m68k Subject: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Oct19.105513.5914@delphi.com> Date: Thu, 19 Oct 1995 10:55:13 GMT Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. 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. Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- === Matthias MacDonald === Dept of Electrical Engineering, Delphi Internet Services "We don't sign stars. We build them." From msouza@u-tokyo.ac.jp Thu Oct 19 11:52:13 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!u-tokyo!msouza From: msouza@u-tokyo.ac.jp (Mathieu Souza) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Oct19.115213.7016@u-tokyo.ac.jp> Date: Thu, 19 Oct 1995 11:52:13 GMT References: <1995Oct19.105513.5914@delphi.com> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Oct19.105513.5914@delphi.com>, mmacdonald@delphi.com (Matthias MacDonald) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Mathieu Souza | msouza@u-tokyo.ac.jp PGP Key fingerprint: 52CD 8BC9 5873 BD54 "Keep the channels open." From jmartinez@inria.fr Fri Oct 20 21:52:13 1995 Path: ashpoly!cascade!transat!ukc!fennimore!inria!jmartinez From: jmartinez@inria.fr (Jen Martínez) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Oct20.215213.3285@inria.fr> Date: Fri, 20 Oct 1995 21:52:13 GMT References: <1995Oct19.105513.5914@delphi.com> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Oct19.105513.5914@delphi.com>, mmacdonald@delphi.com (Matthias MacDonald) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Jen Martínez US Robotics Courier V.34 @ 28,800 bps "We don't sign stars. We build them."