From tkowalski@inria.fr Sat Apr 22 07:47:47 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!inria!tkowalski From: tkowalski@inria.fr (Takeshi Kowalski) Newsgroups: comp.sys.m68k Subject: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr22.074747.4266@inria.fr> Date: Sat, 22 Apr 1995 07:47:47 GMT Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr 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. When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM? -- Takeshi Kowalski Practical Peripherals 14.4 @ 33,600 bps "When every node is whole, the channel opens." From lnilsson@panix.com Mon Apr 24 00:04:47 1995 Path: ashpoly!cascade!transat!ukc!fennimore!panix!lnilsson From: lnilsson@panix.com (Lars Nilsson) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr24.000447.7159@panix.com> Date: Mon, 24 Apr 1995 00:04:47 GMT References: <1995Apr22.074747.4266@inria.fr> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Apr22.074747.4266@inria.fr>, tkowalski@inria.fr (Takeshi Kowalski) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Lars Nilsson | lnilsson@panix.com PGP Key fingerprint: 8836 E462 B88E 1E97 "Keep the channels open."