From jweber@inria.fr Sun Sep 03 08:21:44 1995 Path: ashpoly!cascade!brgate!saturno!inria!jweber From: jweber@inria.fr (Jen Weber) Newsgroups: comp.sys.m68k Subject: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Sep03.082144.7899@inria.fr> Date: Sun, 03 Sep 1995 08:21:44 GMT Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. 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. Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Jen Weber *PLONK* filter active for trolls. Pentium 90 (OS/2 Warp) - NetBSD 1.0 From acampbell@unam.mx Sun Sep 03 17:08:44 1995 Path: ashpoly!cascade!transat!ukc!fennimore!unam!acampbell From: acampbell@unam.mx (Anton Campbell) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Sep03.170844.8830@unam.mx> Date: Sun, 03 Sep 1995 17:08:44 GMT References: <1995Sep03.082144.7899@inria.fr> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Sep03.082144.7899@inria.fr>, jweber@inria.fr (Jen Weber) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > 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. -- === Anton Campbell === Dept of Electrical Engineering, Universidad Nacional Autónoma de México (DGSCA) "Tape doesn't lie at 02:14. Ears do." From cmuller@demon.co.uk Sun Sep 03 19:58:44 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!demon!cmuller From: cmuller@demon.co.uk (Callum Müller) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Sep03.195844.6260@demon.co.uk> Date: Sun, 03 Sep 1995 19:58:44 GMT References: <1995Sep03.082144.7899@inria.fr> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: Netscape 1.1N Lines: 8 In article <1995Sep03.082144.7899@inria.fr>, jweber@inria.fr (Jen Weber) 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! -- Callum Müller -- Demon Internet Services UK "Extraordinary claims require extraordinary spectra." From pkim@cern.ch Sun Sep 03 21:15:44 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!cern!pkim From: pkim@cern.ch (Pavel Kim) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Sep03.211544.4830@cern.ch> Date: Sun, 03 Sep 1995 21:15:44 GMT References: <1995Sep03.082144.7899@inria.fr> <1995Sep03.170844.8830@unam.mx> Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Sep03.170844.8830@unam.mx>, acampbell@unam.mx (Anton Campbell) 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. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- === Pavel Kim === Dept of Electrical Engineering, European Laboratory for Particle Physics, Geneva "Tape doesn't lie at 02:14. Ears do."