From aokonkwo@cmu.edu Mon Dec 16 21:15:38 1996 Path: ashpoly!cascade!transat!sunet!nordrelay!cmu!aokonkwo From: aokonkwo@cmu.edu (Astrid Okonkwo) Newsgroups: comp.sys.m68k Subject: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Dec16.211538.4621@cmu.edu> Date: Mon, 16 Dec 1996 21:15:38 GMT Organization: Carnegie Mellon University School of CS NNTP-Posting-Host: cmu.edu X-Newsreader: Netscape 1.1N Lines: 11 Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. 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. 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. -- Astrid Okonkwo SupraFAXModem 28.8 @ ISDN 64k bps "Tape doesn't lie at 02:14. Ears do." From mwatanabe@uni-hamburg.de Tue Dec 17 02:11:38 1996 Path: ashpoly!cascade!brgate!saturno!uni-hamburg!mwatanabe From: mwatanabe@uni-hamburg.de (Mateo Watanabe) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Dec17.021138.9533@uni-hamburg.de> Date: Tue, 17 Dec 1996 02:11:38 GMT References: <1996Dec16.211538.4621@cmu.edu> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Dec16.211538.4621@cmu.edu>, aokonkwo@cmu.edu (Astrid Okonkwo) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Mateo Watanabe Opinions expressed are solely my own and not those of Universität Hamburg Fachbereich Informatik. ------------------------------------------------------------ From lmuller@ox.ac.uk Thu Dec 19 00:46:38 1996 Path: ashpoly!cascade!brgate!saturno!ox!lmuller From: lmuller@ox.ac.uk (Liam Müller) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Dec19.004638.9323@ox.ac.uk> Date: Thu, 19 Dec 1996 00:46:38 GMT References: <1996Dec16.211538.4621@cmu.edu> <1996Dec17.021138.9533@uni-hamburg.de> Organization: Oxford University Computing Laboratory NNTP-Posting-Host: ox.ac.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Dec17.021138.9533@uni-hamburg.de>, mwatanabe@uni-hamburg.de (Mateo Watanabe) writes: > Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- Liam Müller Hayes Optima 288 @ 14,400 bps "There are 14 nodes and only 10 countries. Count again." From mschneider@unam.mx Thu Dec 19 11:51:38 1996 Path: ashpoly!cascade!brgate!saturno!unam!mschneider From: mschneider@unam.mx (Mateo Schneider) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Dec19.115138.3916@unam.mx> Date: Thu, 19 Dec 1996 11:51:38 GMT References: <1996Dec16.211538.4621@cmu.edu> <1996Dec17.021138.9533@uni-hamburg.de> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Dec17.021138.9533@uni-hamburg.de>, mwatanabe@uni-hamburg.de (Mateo Watanabe) writes: > Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Mateo Schneider | mschneider@unam.mx PGP Key fingerprint: C561 5EBD 1750 19CC "Keep the channels open."