From hito@titech.ac.jp Mon Nov 20 13:41:34 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!titech!hito From: hito@titech.ac.jp (Hana Ito) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov20.134134.7756@titech.ac.jp> Date: Mon, 20 Nov 1995 13:41:34 GMT Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: Netscape 1.1N 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! -- Hana Ito Opinions expressed are solely my own and not those of Tokyo Institute of Technology Computer Centre. ------------------------------------------------------------ From rsmirnov@berkeley.edu Wed Nov 22 16:02:34 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!berkeley!rsmirnov From: rsmirnov@berkeley.edu (Rodrigo Smirnov) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov22.160234.9090@berkeley.edu> Date: Wed, 22 Nov 1995 16:02:34 GMT References: <1995Nov20.134134.7756@titech.ac.jp> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Nov20.134134.7756@titech.ac.jp>, hito@titech.ac.jp (Hana Ito) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- Rodrigo Smirnov SupraFAXModem 28.8 @ 9600 Telebit bps "Tape doesn't lie at 02:14. Ears do." From tsanchez@demon.co.uk Fri Nov 24 13:33:34 1995 Path: ashpoly!cascade!transat!ukc!fennimore!demon!tsanchez From: tsanchez@demon.co.uk (Thiago Sánchez) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov24.133334.6326@demon.co.uk> Date: Fri, 24 Nov 1995 13:33:34 GMT References: <1995Nov20.134134.7756@titech.ac.jp> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Nov20.134134.7756@titech.ac.jp>, hito@titech.ac.jp (Hana Ito) 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? -- Thiago Sánchez "Do not worship the copy." Sun SparcStation 20 / SunOS 4.1.4