From csuzuki@delphi.com Fri Apr 28 00:35:54 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!delphi!csuzuki From: csuzuki@delphi.com (Camila Suzuki) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr28.003554.9843@delphi.com> Date: Fri, 28 Apr 1995 00:35:54 GMT Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: Netscape 1.1N Lines: 11 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Camila Suzuki | csuzuki@delphi.com PGP Key fingerprint: 9F97 C3F0 DE18 9047 "Keep the channels open." From trobertson@unam.mx Sun Apr 30 03:12:54 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!unam!trobertson From: trobertson@unam.mx (Tobias Robertson) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr30.031254.4413@unam.mx> Date: Sun, 30 Apr 1995 03:12:54 GMT References: <1995Apr28.003554.9843@delphi.com> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Apr28.003554.9843@delphi.com>, csuzuki@delphi.com (Camila Suzuki) 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. -- Tobias Robertson SupraFAXModem 28.8 @ 28,800 bps "There are 14 nodes and only 10 countries. Count again." From mgarcia@clari.net Sun Apr 30 10:17:54 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!clari!mgarcia From: mgarcia@clari.net (Mei García) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr30.101754.1590@clari.net> Date: Sun, 30 Apr 1995 10:17:54 GMT References: <1995Apr28.003554.9843@delphi.com> <1995Apr30.031254.4413@unam.mx> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Apr30.031254.4413@unam.mx>, trobertson@unam.mx (Tobias Robertson) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Mei García Opinions expressed are solely my own and not those of ClariNet Communications Corp. ------------------------------------------------------------