From ktanaka@pipeline.com Sat Nov 02 15:09:07 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!pipeline!ktanaka From: ktanaka@pipeline.com (Katrin Tanaka) Newsgroups: comp.sys.m68k Subject: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Nov02.150907.6505@pipeline.com> Date: Sat, 02 Nov 1996 15:09:07 GMT Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.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. 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. Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames! -- Katrin Tanaka | ktanaka@pipeline.com PGP Key fingerprint: 9E85 1976 D88D 1628 "Keep the channels open." From mpark@earthlink.net Sun Nov 03 12:22:07 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!earthlink!mpark From: mpark@earthlink.net (Mei Park) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Nov03.122207.2167@earthlink.net> Date: Sun, 03 Nov 1996 12:22:07 GMT References: <1996Nov02.150907.6505@pipeline.com> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1996Nov02.150907.6505@pipeline.com>, ktanaka@pipeline.com (Katrin Tanaka) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Mei Park "Row 14. No joke." Atari Falcon 030 / System 7.5.1 From dgirard@pacbell.net Tue Nov 05 12:00:07 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!pacbell!dgirard From: dgirard@pacbell.net (Dmitri Girard) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Nov05.120007.7966@pacbell.net> Date: Tue, 05 Nov 1996 12:00:07 GMT References: <1996Nov02.150907.6505@pipeline.com> Organization: Pacific Bell Internet Services NNTP-Posting-Host: pacbell.net X-Newsreader: Netscape 1.1N Lines: 10 In article <1996Nov02.150907.6505@pipeline.com>, ktanaka@pipeline.com (Katrin Tanaka) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Dmitri Girard Hayes Optima 288 @ 33,600 bps "They will send a copy in my place."