From aeriksson@mit.edu Wed Oct 25 09:17:28 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!mit!aeriksson From: aeriksson@mit.edu (Anja Eriksson) Newsgroups: comp.sys.m68k Subject: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Oct25.091728.7364@mit.edu> Date: Wed, 25 Oct 1995 09:17:28 GMT Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: NewsWatcher 2.0b24 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. -- Anja Eriksson *PLONK* filter active for trolls. NeXTstation Turbo Color - NetBSD 1.0 From fmacdonald@uni-hamburg.de Thu Oct 26 20:33:28 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!uni-hamburg!fmacdonald From: fmacdonald@uni-hamburg.de (Fiona MacDonald) Newsgroups: comp.sys.m68k Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Oct26.203328.5694@uni-hamburg.de> Date: Thu, 26 Oct 1995 20:33:28 GMT References: <1995Oct25.091728.7364@mit.edu> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Oct25.091728.7364@mit.edu>, aeriksson@mit.edu (Anja Eriksson) 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. -- Fiona MacDonald | fmacdonald@uni-hamburg.de PGP Key fingerprint: B432 4EB4 C1FC 22EB "Keep the channels open."