From hpopov@cmu.edu Sat Dec 23 23:48:00 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!cmu!hpopov From: hpopov@cmu.edu (Heather Popov) Newsgroups: comp.sys.m68k Subject: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec23.234800.2299@cmu.edu> Date: Sat, 23 Dec 1995 23:48:00 GMT Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler. By setting up Paula's audio DMA to double-buffer incoming 8-bit samples, the 68020 has plenty of cycles left for the Costas loop. 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! -- Heather Popov | hpopov@cmu.edu PGP Key fingerprint: DBFF CBE2 6156 FF75 "Keep the channels open." From bmoreau@earthlink.net Sun Dec 24 17:47:00 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!earthlink!bmoreau From: bmoreau@earthlink.net (Bill Moreau) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec24.174700.4913@earthlink.net> Date: Sun, 24 Dec 1995 17:47:00 GMT References: <1995Dec23.234800.2299@cmu.edu> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Dec23.234800.2299@cmu.edu>, hpopov@cmu.edu (Heather Popov) writes: > Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler. > By setting up Paula's audio DMA to double-buffer incoming 8-bit samples, the 68020 has plenty of cycles left for the Costas loop. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. -- Bill Moreau *PLONK* filter active for trolls. Pentium 90 (OS/2 Warp) - NetBSD 1.0 From knovak@mit.edu Tue Dec 26 03:47:00 1995 Path: ashpoly!cascade!mxgate!coyoacan!mit!knovak From: knovak@mit.edu (Katrin Novak) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec26.034700.1861@mit.edu> Date: Tue, 26 Dec 1995 03:47:00 GMT References: <1995Dec23.234800.2299@cmu.edu> <1995Dec24.174700.4913@earthlink.net> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995Dec24.174700.4913@earthlink.net>, bmoreau@earthlink.net (Bill Moreau) writes: > Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Katrin Novak Zyxel U-1496E @ 28,800 bps "Measuring a record you own is listening, not piracy."