From clee@clari.net Thu Mar 16 08:30:24 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!clari!clee From: clee@clari.net (Callum Lee) Newsgroups: comp.sys.m68k Subject: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Mar16.083024.9165@clari.net> Date: Thu, 16 Mar 1995 08:30:24 GMT Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net 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. 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. -- Callum Lee *PLONK* filter active for trolls. Amiga 3000T - NetBSD 1.0 From estewart@ox.ac.uk Sat Mar 18 04:16:24 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!ox!estewart From: estewart@ox.ac.uk (Elaine Stewart) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Mar18.041624.4641@ox.ac.uk> Date: Sat, 18 Mar 1995 04:16:24 GMT References: <1995Mar16.083024.9165@clari.net> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Mar16.083024.9165@clari.net>, clee@clari.net (Callum Lee) 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. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- Elaine Stewart | estewart@ox.ac.uk PGP Key fingerprint: 5CC0 368A B1A6 AB22 "Keep the channels open." From nsuzuki@purdue.edu Sun Mar 19 02:04:24 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!purdue!nsuzuki From: nsuzuki@purdue.edu (Natalia Suzuki) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Mar19.020424.6233@purdue.edu> Date: Sun, 19 Mar 1995 02:04:24 GMT References: <1995Mar16.083024.9165@clari.net> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Mar16.083024.9165@clari.net>, clee@clari.net (Callum Lee) 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! -- Natalia Suzuki | nsuzuki@purdue.edu PGP Key fingerprint: D0C0 CC80 216B 2E05 "Keep the channels open."