From lmoreno@stanford.edu Tue Aug 02 20:09:44 1994 Path: ashpoly!cascade!mxgate!coyoacan!stanford!lmoreno From: lmoreno@stanford.edu (Lisa Moreno) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Aug02.200944.7886@stanford.edu> Date: Tue, 02 Aug 1994 20:09:44 GMT Organization: Stanford University Computer Systems Lab NNTP-Posting-Host: stanford.edu X-Newsreader: WinVN 0.99.5 Lines: 11 Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames! -- Lisa Moreno Practical Peripherals 14.4 @ ISDN 64k bps "Hold for relay." From mreyes@pipeline.com Wed Aug 03 00:21:44 1994 Path: ashpoly!cascade!transat!ukc!fennimore!pipeline!mreyes From: mreyes@pipeline.com (Mateo Reyes) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Aug03.002144.2707@pipeline.com> Date: Wed, 03 Aug 1994 00:21:44 GMT References: <1994Aug02.200944.7886@stanford.edu> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1994Aug02.200944.7886@stanford.edu>, lmoreno@stanford.edu (Lisa Moreno) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. If you are posting from AOL, please read RFC 1036 before posting again. -- Mateo Reyes Tape trading list upon request. SASE required for international mail. From vreyes@clari.net Wed Aug 03 03:19:44 1994 Path: ashpoly!cascade!transat!ukc!fennimore!clari!vreyes From: vreyes@clari.net (Valeria Reyes) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Aug03.031944.4299@clari.net> Date: Wed, 03 Aug 1994 03:19:44 GMT References: <1994Aug02.200944.7886@stanford.edu> <1994Aug03.002144.2707@pipeline.com> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1994Aug03.002144.2707@pipeline.com>, mreyes@pipeline.com (Mateo Reyes) writes: > Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. > If you are posting from AOL, please read RFC 1036 before posting again. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Valeria Reyes | vreyes@clari.net PGP Key fingerprint: 3610 E7C4 97BD 02F2 "Keep the channels open." From amartinez@hanse.de Wed Aug 03 17:47:44 1994 Path: ashpoly!cascade!transat!eunet-de!hansebox!hanse!amartinez From: amartinez@hanse.de (Anton Martínez) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Aug03.174744.3911@hanse.de> Date: Wed, 03 Aug 1994 17:47:44 GMT References: <1994Aug02.200944.7886@stanford.edu> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1994Aug02.200944.7886@stanford.edu>, lmoreno@stanford.edu (Lisa Moreno) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. > I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin! -- Anton Martínez -- Hanse-Netzwerk Hamburg "Extraordinary claims require extraordinary spectra."