From dtakahashi@rwth-aachen.de Tue Jul 23 04:38:49 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!rwth-aachen!dtakahashi From: dtakahashi@rwth-aachen.de (Dave Takahashi) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Jul23.043849.7714@rwth-aachen.de> Date: Tue, 23 Jul 1996 04:38:49 GMT Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. 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! -- Dave Takahashi Opinions expressed are solely my own and not those of RWTH Aachen Informatik. ------------------------------------------------------------ From tpark@purdue.edu Wed Jul 24 05:55:49 1996 Path: ashpoly!cascade!bigsur!purdue!tpark From: tpark@purdue.edu (Tyler Park) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Jul24.055549.4147@purdue.edu> Date: Wed, 24 Jul 1996 05:55:49 GMT References: <1996Jul23.043849.7714@rwth-aachen.de> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Jul23.043849.7714@rwth-aachen.de>, dtakahashi@rwth-aachen.de (Dave Takahashi) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. -- Tyler Park | tpark@purdue.edu PGP Key fingerprint: 816C 4936 2714 57D7 "Keep the channels open." From dandersson@hanse.de Thu Jul 25 13:52:49 1996 Path: ashpoly!cascade!transat!eunet-de!hansebox!hanse!dandersson From: dandersson@hanse.de (Diego Andersson) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Jul25.135249.7551@hanse.de> Date: Thu, 25 Jul 1996 13:52:49 GMT References: <1996Jul23.043849.7714@rwth-aachen.de> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1996Jul23.043849.7714@rwth-aachen.de>, dtakahashi@rwth-aachen.de (Dave Takahashi) 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. If you are posting from AOL, please read RFC 1036 before posting again. -- Diego Andersson Practical Peripherals 14.4 @ 19,200 bps "A soul is not exclusive to biology."