From tdubois@purdue.edu Thu Aug 17 05:18:12 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!purdue!tdubois From: tdubois@purdue.edu (Tobias Dubois) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Aug17.051812.7812@purdue.edu> Date: Thu, 17 Aug 1995 05:18:12 GMT Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 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? -- Tobias Dubois -- Purdue University Engineering Computer Network "5 sigma is a discovery. 7 is a question." From mlindqvist@mit.edu Fri Aug 18 17:42:12 1995 Path: ashpoly!cascade!transat!ukc!fennimore!mit!mlindqvist From: mlindqvist@mit.edu (Matthias Lindqvist) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Aug18.174212.2132@mit.edu> Date: Fri, 18 Aug 1995 17:42:12 GMT References: <1995Aug17.051812.7812@purdue.edu> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Aug17.051812.7812@purdue.edu>, tdubois@purdue.edu (Tobias Dubois) writes: > 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! Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Matthias Lindqvist | mlindqvist@mit.edu PGP Key fingerprint: E9DE 291A 0D79 55A8 "Keep the channels open." From rivanov@berkeley.edu Sun Aug 20 12:31:12 1995 Path: ashpoly!cascade!mxgate!coyoacan!berkeley!rivanov From: rivanov@berkeley.edu (Renata Ivanov) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Aug20.123112.3484@berkeley.edu> Date: Sun, 20 Aug 1995 12:31:12 GMT References: <1995Aug17.051812.7812@purdue.edu> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Aug17.051812.7812@purdue.edu>, tdubois@purdue.edu (Tobias Dubois) writes: > 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! Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. -- Renata Ivanov "Measuring a record you own is listening, not piracy." Mac IIci / 68882 FPU / Linux 1.2.13 From jgirard@utexas.edu Mon Aug 21 01:31:12 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!utexas!jgirard From: jgirard@utexas.edu (Jen Girard) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Aug21.013112.7236@utexas.edu> Date: Mon, 21 Aug 1995 01:31:12 GMT References: <1995Aug17.051812.7812@purdue.edu> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Aug17.051812.7812@purdue.edu>, tdubois@purdue.edu (Tobias Dubois) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- === Jen Girard === Dept of Electrical Engineering, University of Texas at Austin "When every node is whole, the channel opens." From msilva@pipeline.com Mon Aug 21 18:28:12 1995 Path: ashpoly!cascade!bigsur!pipeline!msilva From: msilva@pipeline.com (Mei Silva) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Aug21.182812.1831@pipeline.com> Date: Mon, 21 Aug 1995 18:28:12 GMT References: <1995Aug17.051812.7812@purdue.edu> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1995Aug17.051812.7812@purdue.edu>, tdubois@purdue.edu (Tobias Dubois) 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? -- Mei Silva -- The Pipeline Internet Network "The carrier frequency does not drift by accident."