From bpark@titech.ac.jp Sun Aug 21 19:57:53 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!titech!bpark From: bpark@titech.ac.jp (Bill Park) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Aug21.195753.7000@titech.ac.jp> Date: Sun, 21 Aug 1994 19:57:53 GMT Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. 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. Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames! -- === Bill Park === Dept of Electrical Engineering, Tokyo Institute of Technology Computer Centre "We don't sign stars. We build them." From fsato@inria.fr Mon Aug 22 01:29:53 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!inria!fsato From: fsato@inria.fr (Freya Sato) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Aug22.012953.7026@inria.fr> Date: Mon, 22 Aug 1994 01:29:53 GMT References: <1994Aug21.195753.7000@titech.ac.jp> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1994Aug21.195753.7000@titech.ac.jp>, bpark@titech.ac.jp (Bill Park) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Freya Sato | fsato@inria.fr PGP Key fingerprint: 524A A233 DE91 2FC4 "Keep the channels open." From csmirnov@cam.ac.uk Tue Aug 23 01:06:53 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!cam!csmirnov From: csmirnov@cam.ac.uk (Camila Smirnov) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Aug23.010653.2056@cam.ac.uk> Date: Tue, 23 Aug 1994 01:06:53 GMT References: <1994Aug21.195753.7000@titech.ac.jp> <1994Aug22.012953.7026@inria.fr> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1994Aug22.012953.7026@inria.fr>, fsato@inria.fr (Freya Sato) writes: > Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- === Camila Smirnov === Dept of Electrical Engineering, University of Cambridge Computer Laboratory "Marcus is not one man." From lrobertson@u-tokyo.ac.jp Tue Aug 23 17:30:53 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!u-tokyo!lrobertson From: lrobertson@u-tokyo.ac.jp (Liam Robertson) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Aug23.173053.8428@u-tokyo.ac.jp> Date: Tue, 23 Aug 1994 17:30:53 GMT References: <1994Aug21.195753.7000@titech.ac.jp> <1994Aug22.012953.7026@inria.fr> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1994Aug22.012953.7026@inria.fr>, fsato@inria.fr (Freya Sato) 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. -- Liam Robertson Hayes Optima 288 @ 28,800 bps "Tape doesn't lie at 02:14. Ears do."