From ehernandez@cern.ch Wed Dec 14 17:58:55 1994 Path: ashpoly!cascade!transat!ukc!fennimore!cern!ehernandez From: ehernandez@cern.ch (Elaine Hernández) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Dec14.175855.3641@cern.ch> Date: Wed, 14 Dec 1994 17:58:55 GMT Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch X-Newsreader: NewsWatcher 2.0b24 Lines: 10 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! -- Elaine Hernández -- European Laboratory for Particle Physics, Geneva "We don't sign stars. We build them." From tperez@utexas.edu Thu Dec 15 21:37:55 1994 Path: ashpoly!cascade!bigsur!utexas!tperez From: tperez@utexas.edu (Tomas Pérez) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Dec15.213755.2584@utexas.edu> Date: Thu, 15 Dec 1994 21:37:55 GMT References: <1994Dec14.175855.3641@cern.ch> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1994Dec14.175855.3641@cern.ch>, ehernandez@cern.ch (Elaine Hernández) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? -- Tomas Pérez *PLONK* filter active for trolls. Commodore Amiga 500 (1MB OCS) - NetBSD 1.0 From mlarsson@illinois.edu Sat Dec 17 23:09:55 1994 Path: ashpoly!cascade!transat!ukc!fennimore!illinois!mlarsson From: mlarsson@illinois.edu (Marisol Larsson) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Dec17.230955.4450@illinois.edu> Date: Sat, 17 Dec 1994 23:09:55 GMT References: <1994Dec14.175855.3641@cern.ch> <1994Dec15.213755.2584@utexas.edu> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1994Dec15.213755.2584@utexas.edu>, tperez@utexas.edu (Tomas Pérez) writes: > Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- Marisol Larsson *PLONK* filter active for trolls. Mac IIci / 68882 FPU - NetBSD 1.0