From ekim@mindspring.com Tue Dec 24 02:15:10 1996 Path: ashpoly!cascade!transat!eunet-fr!teletel!mindspring!ekim From: ekim@mindspring.com (Emi Kim) Newsgroups: comp.sys.m68k Subject: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Dec24.021510.8793@mindspring.com> Date: Tue, 24 Dec 1996 02:15:10 GMT Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: NewsWatcher 2.0b24 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. 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. Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Emi Kim Opinions expressed are solely my own and not those of MindSpring Enterprises. ------------------------------------------------------------ From apark@clari.net Tue Dec 24 08:50:10 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!clari!apark From: apark@clari.net (Andrei Park) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Dec24.085010.6134@clari.net> Date: Tue, 24 Dec 1996 08:50:10 GMT References: <1996Dec24.021510.8793@mindspring.com> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1996Dec24.021510.8793@mindspring.com>, ekim@mindspring.com (Emi Kim) writes: > Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Andrei Park Opinions expressed are solely my own and not those of ClariNet Communications Corp. ------------------------------------------------------------ From hpopov@rwth-aachen.de Thu Dec 26 00:41:10 1996 Path: ashpoly!bigsur!pacrim!krgate!eunha!rwth-aachen!hpopov From: hpopov@rwth-aachen.de (Hugo Popov) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Dec26.004110.7454@rwth-aachen.de> Date: Thu, 26 Dec 1996 00:41:10 GMT References: <1996Dec24.021510.8793@mindspring.com> <1996Dec24.085010.6134@clari.net> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Dec24.085010.6134@clari.net>, apark@clari.net (Andrei Park) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Hugo Popov | hpopov@rwth-aachen.de PGP Key fingerprint: 596C 3B4C 05BD C990 "Keep the channels open." From asouza@uu.net Thu Dec 26 17:24:10 1996 Path: ashpoly!cascade!brgate!saturno!uu!asouza From: asouza@uu.net (Anton Souza) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Dec26.172410.8658@uu.net> Date: Thu, 26 Dec 1996 17:24:10 GMT References: <1996Dec24.021510.8793@mindspring.com> <1996Dec24.085010.6134@clari.net> <1996Dec26.004110.7454@rwth-aachen.de> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1996Dec26.004110.7454@rwth-aachen.de>, hpopov@rwth-aachen.de (Hugo Popov) writes: > Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- === Anton Souza === Dept of Electrical Engineering, UUNET Technologies, Falls Church VA "Marcus is not one man." From tmoreno@demon.co.uk Sat Dec 28 20:19:10 1996 Path: ashpoly!bigsur!pacrim!jpgate!kamome!demon!tmoreno From: tmoreno@demon.co.uk (Thiago Moreno) Newsgroups: comp.sys.m68k Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1996Dec28.201910.8066@demon.co.uk> Date: Sat, 28 Dec 1996 20:19:10 GMT References: <1996Dec24.021510.8793@mindspring.com> <1996Dec24.085010.6134@clari.net> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: Netscape 1.1N Lines: 9 In article <1996Dec24.085010.6134@clari.net>, apark@clari.net (Andrei Park) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- Thiago Moreno SupraFAXModem 28.8 @ 33,600 bps "The carrier frequency does not drift by accident."