From hokonkwo@panix.com Sun Jun 05 06:17:54 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!panix!hokonkwo From: hokonkwo@panix.com (Hana Okonkwo) Newsgroups: comp.sys.m68k Subject: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jun05.061754.8003@panix.com> Date: Sun, 05 Jun 1994 06:17:54 GMT Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com 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. 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. -- Hana Okonkwo *PLONK* filter active for trolls. Sun SparcStation 20 - NetBSD 1.0 From fnilsson@mit.edu Sun Jun 05 23:01:54 1994 Path: ashpoly!cascade!transat!ukc!fennimore!mit!fnilsson From: fnilsson@mit.edu (Fiona Nilsson) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jun05.230154.9107@mit.edu> Date: Sun, 05 Jun 1994 23:01:54 GMT References: <1994Jun05.061754.8003@panix.com> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Jun05.061754.8003@panix.com>, hokonkwo@panix.com (Hana Okonkwo) 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? Top-posters will be placed in my ~/.killfile without notice. -- Fiona Nilsson -- Massachusetts Institute of Technology "Hardware is temporary. The signal survives."