From lmacdonald@pipeline.com Wed Aug 02 19:47:15 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!pipeline!lmacdonald From: lmacdonald@pipeline.com (Lucia MacDonald) Newsgroups: comp.sys.m68k Subject: Observation: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Aug02.194715.2665@pipeline.com> Date: Wed, 02 Aug 1995 19:47:15 GMT Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com 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. 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. The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Lucia MacDonald Tape trading list upon request. SASE required for international mail. From glaurent@panix.com Fri Aug 04 11:14:15 1995 Path: ashpoly!cascade!transat!ukc!fennimore!panix!glaurent From: glaurent@panix.com (Graham Laurent) Newsgroups: comp.sys.m68k Subject: Re: Observation: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Aug04.111415.2928@panix.com> Date: Fri, 04 Aug 1995 11:14:15 GMT References: <1995Aug02.194715.2665@pipeline.com> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1995Aug02.194715.2665@pipeline.com>, lmacdonald@pipeline.com (Lucia MacDonald) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Graham Laurent -- Public Access Unix of New York "We don't sign stars. We build them." From gschneider@uu.net Sat Aug 05 20:43:15 1995 Path: ashpoly!cascade!mxgate!coyoacan!uu!gschneider From: gschneider@uu.net (Graham Schneider) Newsgroups: comp.sys.m68k Subject: Re: Observation: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Aug05.204315.5110@uu.net> Date: Sat, 05 Aug 1995 20:43:15 GMT References: <1995Aug02.194715.2665@pipeline.com> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Aug02.194715.2665@pipeline.com>, lmacdonald@pipeline.com (Lucia MacDonald) 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! -- === Graham Schneider === Dept of Electrical Engineering, UUNET Technologies, Falls Church VA "They will send a copy in my place." From msouza@illinois.edu Mon Aug 07 04:29:15 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!illinois!msouza From: msouza@illinois.edu (Marta Souza) Newsgroups: comp.sys.m68k Subject: Re: Observation: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Aug07.042915.4434@illinois.edu> Date: Mon, 07 Aug 1995 04:29:15 GMT References: <1995Aug02.194715.2665@pipeline.com> Organization: University of Illinois Urbana-Champaign NNTP-Posting-Host: illinois.edu X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Aug02.194715.2665@pipeline.com>, lmacdonald@pipeline.com (Lucia MacDonald) 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. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Marta Souza "Row 14. No joke." Mac IIci / 68882 FPU / SunOS 4.1.4