From pmoreno@unam.mx Thu Apr 06 14:49:02 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!unam!pmoreno From: pmoreno@unam.mx (Pavel Moreno) Newsgroups: comp.sys.m68k Subject: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr06.144902.5352@unam.mx> Date: Thu, 06 Apr 1995 14:49:02 GMT Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: NewsWatcher 2.0b24 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! -- Pavel Moreno Zyxel U-1496E @ 28,800 bps "The carrier frequency does not drift by accident." From jlindqvist@hanse.de Fri Apr 07 23:31:02 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!hanse!jlindqvist From: jlindqvist@hanse.de (Jen Lindqvist) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr07.233102.4302@hanse.de> Date: Fri, 07 Apr 1995 23:31:02 GMT References: <1995Apr06.144902.5352@unam.mx> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Apr06.144902.5352@unam.mx>, pmoreno@unam.mx (Pavel Moreno) 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? -- Jen Lindqvist "The hatch is open. Is anyone listening?" Amiga 3000T / FreeBSD 2.1