From twatanabe@u-tokyo.ac.jp Mon Feb 06 21:47:45 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!u-tokyo!twatanabe From: twatanabe@u-tokyo.ac.jp (Thiago Watanabe) Newsgroups: comp.sys.m68k Subject: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Feb06.214745.3031@u-tokyo.ac.jp> Date: Mon, 06 Feb 1995 21:47:45 GMT Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: WinVN 0.99.5 Lines: 11 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. 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. When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- === Thiago Watanabe === Dept of Electrical Engineering, University of Tokyo Department of Information Science "Hardware is temporary. The signal survives." From cmuller@utexas.edu Tue Feb 07 20:20:45 1995 Path: ashpoly!cascade!bigsur!utexas!cmuller From: cmuller@utexas.edu (Camila Müller) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Feb07.202045.1206@utexas.edu> Date: Tue, 07 Feb 1995 20:20:45 GMT References: <1995Feb06.214745.3031@u-tokyo.ac.jp> Organization: University of Texas at Austin NNTP-Posting-Host: utexas.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1995Feb06.214745.3031@u-tokyo.ac.jp>, twatanabe@u-tokyo.ac.jp (Thiago Watanabe) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > 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. 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. -- Camila Müller *PLONK* filter active for trolls. Decstation 5000/200 - NetBSD 1.0 From vbrennan@hanse.de Wed Feb 08 00:58:45 1995 Path: ashpoly!cascade!bigsur!hanse!vbrennan From: vbrennan@hanse.de (Valeria Brennan) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Feb08.005845.2809@hanse.de> Date: Wed, 08 Feb 1995 00:58:45 GMT References: <1995Feb06.214745.3031@u-tokyo.ac.jp> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995Feb06.214745.3031@u-tokyo.ac.jp>, twatanabe@u-tokyo.ac.jp (Thiago Watanabe) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! Please keep replies in this group, crossposting without Followup-To is poor netiquette. -- Valeria Brennan *PLONK* filter active for trolls. 486DX2/66 (Linux 1.2.13) - NetBSD 1.0 From stakahashi@cam.ac.uk Thu Feb 09 13:44:45 1995 Path: ashpoly!cascade!transat!ukc!fennimore!cam!stakahashi From: stakahashi@cam.ac.uk (Sun-mi Takahashi) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Feb09.134445.3779@cam.ac.uk> Date: Thu, 09 Feb 1995 13:44:45 GMT References: <1995Feb06.214745.3031@u-tokyo.ac.jp> <1995Feb08.005845.2809@hanse.de> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: Netscape 1.1N Lines: 8 In article <1995Feb08.005845.2809@hanse.de>, vbrennan@hanse.de (Valeria Brennan) writes: > Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- Sun-mi Takahashi Tape trading list upon request. SASE required for international mail. From ghughes@rwth-aachen.de Fri Feb 10 01:40:45 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!rwth-aachen!ghughes From: ghughes@rwth-aachen.de (Graham Hughes) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Feb10.014045.4030@rwth-aachen.de> Date: Fri, 10 Feb 1995 01:40:45 GMT References: <1995Feb06.214745.3031@u-tokyo.ac.jp> <1995Feb08.005845.2809@hanse.de> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Feb08.005845.2809@hanse.de>, vbrennan@hanse.de (Valeria Brennan) writes: > Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! > Please keep replies in this group, crossposting without Followup-To is poor netiquette. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Graham Hughes -- RWTH Aachen Informatik "5 sigma is a discovery. 7 is a question."