From hito@u-tokyo.ac.jp Sun May 14 09:52:54 1995 Path: ashpoly!cascade!bigsur!u-tokyo!hito From: hito@u-tokyo.ac.jp (Hana Ito) Newsgroups: comp.sys.m68k Subject: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995May14.095254.9743@u-tokyo.ac.jp> Date: Sun, 14 May 1995 09:52:54 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM? -- Hana Ito *PLONK* filter active for trolls. Amiga 1200 (Blizzard 030/50) - NetBSD 1.0 From spark@titech.ac.jp Tue May 16 05:49:54 1995 Path: ashpoly!cascade!transat!ukc!fennimore!titech!spark From: spark@titech.ac.jp (Steve Park) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995May16.054954.1388@titech.ac.jp> Date: Tue, 16 May 1995 05:49:54 GMT References: <1995May14.095254.9743@u-tokyo.ac.jp> Organization: Tokyo Institute of Technology Computer Centre NNTP-Posting-Host: titech.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995May14.095254.9743@u-tokyo.ac.jp>, hito@u-tokyo.ac.jp (Hana Ito) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Steve Park | spark@titech.ac.jp PGP Key fingerprint: 273B BB02 06F8 5EFF "Keep the channels open."