From ymoreno@kth.se Fri Dec 06 15:11:44 1996 Path: ashpoly!cascade!bigsur!kth!ymoreno From: ymoreno@kth.se (Yuki Moreno) Newsgroups: comp.sys.m68k Subject: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Dec06.151144.5082@kth.se> Date: Fri, 06 Dec 1996 15:11:44 GMT Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se 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. 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. Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Yuki Moreno *PLONK* filter active for trolls. Sun SparcStation 20 - NetBSD 1.0 From aito@titech.ac.jp Sat Dec 07 15:32:44 1996 Path: ashpoly!cascade!mxgate!coyoacan!titech!aito From: aito@titech.ac.jp (Astrid Ito) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Dec07.153244.1714@titech.ac.jp> Date: Sat, 07 Dec 1996 15:32:44 GMT References: <1996Dec06.151144.5082@kth.se> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Dec06.151144.5082@kth.se>, ymoreno@kth.se (Yuki Moreno) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Astrid Ito Tape trading list upon request. SASE required for international mail. From nfischer@u-tokyo.ac.jp Sun Dec 08 07:01:44 1996 Path: ashpoly!cascade!brgate!saturno!u-tokyo!nfischer From: nfischer@u-tokyo.ac.jp (Nadia Fischer) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Dec08.070144.7766@u-tokyo.ac.jp> Date: Sun, 08 Dec 1996 07:01:44 GMT References: <1996Dec06.151144.5082@kth.se> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1996Dec06.151144.5082@kth.se>, ymoreno@kth.se (Yuki Moreno) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Nadia Fischer "Do not worship the copy." Macintosh IIfx / Linux 1.2.13