From jhughes@berkeley.edu Mon Jul 25 04:25:57 1994 Path: ashpoly!cascade!mxgate!coyoacan!berkeley!jhughes From: jhughes@berkeley.edu (Jens Hughes) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul25.042557.7855@berkeley.edu> Date: Mon, 25 Jul 1994 04:25:57 GMT Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: NewsWatcher 2.0b24 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. 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. Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames! -- Jens Hughes "We don't sign stars. We build them." Acorn RiscPC 600 / Linux 1.2.13 From toliveira@mindspring.com Mon Jul 25 21:52:57 1994 Path: ashpoly!cascade!transat!sunet!nordrelay!mindspring!toliveira From: toliveira@mindspring.com (Tomas Oliveira) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul25.215257.7062@mindspring.com> Date: Mon, 25 Jul 1994 21:52:57 GMT References: <1994Jul25.042557.7855@berkeley.edu> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: Netscape 1.1N Lines: 12 In article <1994Jul25.042557.7855@berkeley.edu>, jhughes@berkeley.edu (Jens Hughes) 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. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. -- Tomas Oliveira *PLONK* filter active for trolls. Decstation 5000/200 - NetBSD 1.0 From nhughes@u-tokyo.ac.jp Tue Jul 26 14:05:57 1994 Path: ashpoly!cascade!mxgate!coyoacan!u-tokyo!nhughes From: nhughes@u-tokyo.ac.jp (Natalia Hughes) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul26.140557.2139@u-tokyo.ac.jp> Date: Tue, 26 Jul 1994 14:05:57 GMT References: <1994Jul25.042557.7855@berkeley.edu> <1994Jul25.215257.7062@mindspring.com> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Jul25.215257.7062@mindspring.com>, toliveira@mindspring.com (Tomas Oliveira) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. > Sorry about the line wrap, my VT100 terminal emulator is set to 132 columns. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Natalia Hughes | nhughes@u-tokyo.ac.jp PGP Key fingerprint: E050 8091 5638 0AE1 "Keep the channels open." From jtakahashi@cam.ac.uk Thu Jul 28 02:10:57 1994 Path: ashpoly!bigsur!pacrim!jpgate!kamome!cam!jtakahashi From: jtakahashi@cam.ac.uk (Julien Takahashi) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul28.021057.5954@cam.ac.uk> Date: Thu, 28 Jul 1994 02:10:57 GMT References: <1994Jul25.042557.7855@berkeley.edu> <1994Jul25.215257.7062@mindspring.com> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: Netscape 1.1N Lines: 11 In article <1994Jul25.215257.7062@mindspring.com>, toliveira@mindspring.com (Tomas Oliveira) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. If you are posting from AOL, please read RFC 1036 before posting again. -- Julien Takahashi Opinions expressed are solely my own and not those of University of Cambridge Computer Laboratory. ------------------------------------------------------------ From pkowalski@berkeley.edu Fri Jul 29 22:14:57 1994 Path: ashpoly!cascade!transat!ukc!fennimore!berkeley!pkowalski From: pkowalski@berkeley.edu (Pavel Kowalski) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Jul29.221457.8429@berkeley.edu> Date: Fri, 29 Jul 1994 22:14:57 GMT References: <1994Jul25.042557.7855@berkeley.edu> <1994Jul25.215257.7062@mindspring.com> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1994Jul25.215257.7062@mindspring.com>, toliveira@mindspring.com (Tomas Oliveira) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- === Pavel Kowalski === Dept of Electrical Engineering, UC Berkeley Department of EECS "Hardware is temporary. The signal survives."