From estewart@u-tokyo.ac.jp Fri Sep 02 22:17:03 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!u-tokyo!estewart From: estewart@u-tokyo.ac.jp (Emi Stewart) Newsgroups: comp.sys.m68k Subject: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Sep02.221703.5366@u-tokyo.ac.jp> Date: Fri, 02 Sep 1994 22:17:03 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp 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. 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. -- Emi Stewart Opinions expressed are solely my own and not those of University of Tokyo Department of Information Science. ------------------------------------------------------------ From lchoi@demon.co.uk Sun Sep 04 23:07:03 1994 Path: ashpoly!cascade!bigsur!demon!lchoi From: lchoi@demon.co.uk (Lucia Choi) Newsgroups: comp.sys.m68k Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Sep04.230703.7620@demon.co.uk> Date: Sun, 04 Sep 1994 23:07:03 GMT References: <1994Sep02.221703.5366@u-tokyo.ac.jp> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1994Sep02.221703.5366@u-tokyo.ac.jp>, estewart@u-tokyo.ac.jp (Emi Stewart) 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? -- Lucia Choi *PLONK* filter active for trolls. Sun SparcStation 20 - NetBSD 1.0