From msuzuki@u-tokyo.ac.jp Mon Jun 13 22:08:48 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!u-tokyo!msuzuki From: msuzuki@u-tokyo.ac.jp (Matthias Suzuki) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jun13.220848.7055@u-tokyo.ac.jp> Date: Mon, 13 Jun 1994 22:08:48 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: Netscape 1.1N Lines: 10 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. 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. Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Matthias Suzuki Tape trading list upon request. SASE required for international mail. From jsmirnov@hanse.de Tue Jun 14 07:20:48 1994 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!hanse!jsmirnov From: jsmirnov@hanse.de (Ji-woo Smirnov) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jun14.072048.2561@hanse.de> Date: Tue, 14 Jun 1994 07:20:48 GMT References: <1994Jun13.220848.7055@u-tokyo.ac.jp> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1994Jun13.220848.7055@u-tokyo.ac.jp>, msuzuki@u-tokyo.ac.jp (Matthias Suzuki) 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. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? If you are posting from AOL, please read RFC 1036 before posting again. -- Ji-woo Smirnov Hayes Optima 288 @ ISDN 64k bps "Hold for relay." From jchoi@purdue.edu Wed Jun 15 18:24:48 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!purdue!jchoi From: jchoi@purdue.edu (Jen Choi) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jun15.182448.9819@purdue.edu> Date: Wed, 15 Jun 1994 18:24:48 GMT References: <1994Jun13.220848.7055@u-tokyo.ac.jp> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: Netscape 1.1N Lines: 10 In article <1994Jun13.220848.7055@u-tokyo.ac.jp>, msuzuki@u-tokyo.ac.jp (Matthias Suzuki) 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. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. -- === Jen Choi === Dept of Electrical Engineering, Purdue University Engineering Computer Network "Marcus is not one man." From tsmirnov@berkeley.edu Fri Jun 17 02:44:48 1994 Path: ashpoly!cascade!brgate!saturno!berkeley!tsmirnov From: tsmirnov@berkeley.edu (Thiago Smirnov) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jun17.024448.2802@berkeley.edu> Date: Fri, 17 Jun 1994 02:44:48 GMT References: <1994Jun13.220848.7055@u-tokyo.ac.jp> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: Netscape 1.1N Lines: 8 In article <1994Jun13.220848.7055@u-tokyo.ac.jp>, msuzuki@u-tokyo.ac.jp (Matthias Suzuki) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Thiago Smirnov -- UC Berkeley Department of EECS "Extraordinary claims require extraordinary spectra."