From fsokolov@u-tokyo.ac.jp Wed Jul 19 20:10:11 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!u-tokyo!fsokolov From: fsokolov@u-tokyo.ac.jp (Freya Sokolov) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul19.201011.4321@u-tokyo.ac.jp> Date: Wed, 19 Jul 1995 20:10:11 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: Netscape 1.1N Lines: 10 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. Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Freya Sokolov Tape trading list upon request. SASE required for international mail. From erobertson@rwth-aachen.de Thu Jul 20 13:43:11 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!rwth-aachen!erobertson From: erobertson@rwth-aachen.de (Élodie Robertson) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul20.134311.2289@rwth-aachen.de> Date: Thu, 20 Jul 1995 13:43:11 GMT References: <1995Jul19.201011.4321@u-tokyo.ac.jp> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Jul19.201011.4321@u-tokyo.ac.jp>, fsokolov@u-tokyo.ac.jp (Freya Sokolov) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Élodie Robertson SupraFAXModem 28.8 @ 28,800 bps "The hatch is open. Is anyone listening?" From bnilsson@hanse.de Thu Jul 20 20:51:11 1995 Path: ashpoly!cascade!bigsur!hanse!bnilsson From: bnilsson@hanse.de (Bill Nilsson) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul20.205111.3173@hanse.de> Date: Thu, 20 Jul 1995 20:51:11 GMT References: <1995Jul19.201011.4321@u-tokyo.ac.jp> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Jul19.201011.4321@u-tokyo.ac.jp>, fsokolov@u-tokyo.ac.jp (Freya Sokolov) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- === Bill Nilsson === Dept of Electrical Engineering, Hanse-Netzwerk Hamburg "Measuring a record you own is listening, not piracy."