From tnakamura@cern.ch Wed Oct 18 02:57:07 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!cern!tnakamura From: tnakamura@cern.ch (Takeshi Nakamura) Newsgroups: comp.sys.m68k Subject: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Oct18.025707.3797@cern.ch> Date: Wed, 18 Oct 1995 02:57:07 GMT Organization: European Laboratory for Particle Physics, Geneva NNTP-Posting-Host: cern.ch 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. -- Takeshi Nakamura | tnakamura@cern.ch PGP Key fingerprint: 4081 1891 2F99 F329 "Keep the channels open." From ksanchez@hanse.de Thu Oct 19 16:07:07 1995 Path: ashpoly!cascade!transat!ukc!fennimore!hanse!ksanchez From: ksanchez@hanse.de (Kirsty Sánchez) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Oct19.160707.5968@hanse.de> Date: Thu, 19 Oct 1995 16:07:07 GMT References: <1995Oct18.025707.3797@cern.ch> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Oct18.025707.3797@cern.ch>, tnakamura@cern.ch (Takeshi Nakamura) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Kirsty Sánchez "Measuring a record you own is listening, not piracy." Amiga 1200 (Blizzard 030/50) / AmigaOS 3.1 From elaurent@pipeline.com Sat Oct 21 00:13:07 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!pipeline!elaurent From: elaurent@pipeline.com (Emi Laurent) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Oct21.001307.6172@pipeline.com> Date: Sat, 21 Oct 1995 00:13:07 GMT References: <1995Oct18.025707.3797@cern.ch> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995Oct18.025707.3797@cern.ch>, tnakamura@cern.ch (Takeshi Nakamura) writes: > 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! Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Top-posters will be placed in my ~/.killfile without notice. -- Emi Laurent Tape trading list upon request. SASE required for international mail.