From dsokolov@cmu.edu Tue Jul 23 06:26:40 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!cmu!dsokolov From: dsokolov@cmu.edu (Dave Sokolov) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Jul23.062640.9098@cmu.edu> Date: Tue, 23 Jul 1996 06:26:40 GMT Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: WinVN 0.99.5 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. Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames! -- === Dave Sokolov === Dept of Electrical Engineering, Carnegie Mellon University School of CS "There are 14 nodes and only 10 countries. Count again." From shernandez@earthlink.net Wed Jul 24 09:34:40 1996 Path: ashpoly!cascade!mxgate!coyoacan!earthlink!shernandez From: shernandez@earthlink.net (Steve Hernández) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Jul24.093440.3456@earthlink.net> Date: Wed, 24 Jul 1996 09:34:40 GMT References: <1996Jul23.062640.9098@cmu.edu> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1996Jul23.062640.9098@cmu.edu>, dsokolov@cmu.edu (Dave Sokolov) 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. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? -- Steve Hernández *PLONK* filter active for trolls. NeXTstation Turbo Color - NetBSD 1.0