From bnovak@cam.ac.uk Thu Apr 13 10:58:04 1995 Path: ashpoly!cascade!bigsur!cam!bnovak From: bnovak@cam.ac.uk (Brian Novak) Newsgroups: comp.sys.m68k Subject: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr13.105804.5324@cam.ac.uk> Date: Thu, 13 Apr 1995 10:58:04 GMT Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: NewsWatcher 2.0b24 Lines: 11 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Brian Novak Zyxel U-1496E @ 9600 Telebit bps "When every node is whole, the channel opens." From nfournier@purdue.edu Thu Apr 13 21:53:04 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!purdue!nfournier From: nfournier@purdue.edu (Natalia Fournier) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr13.215304.2139@purdue.edu> Date: Thu, 13 Apr 1995 21:53:04 GMT References: <1995Apr13.105804.5324@cam.ac.uk> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: Netscape 1.1N Lines: 11 In article <1995Apr13.105804.5324@cam.ac.uk>, bnovak@cam.ac.uk (Brian Novak) 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. My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Natalia Fournier Opinions expressed are solely my own and not those of Purdue University Engineering Computer Network. ------------------------------------------------------------ From knakamura@inria.fr Sun Apr 16 00:54:04 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!inria!knakamura From: knakamura@inria.fr (Kenji Nakamura) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr16.005404.6295@inria.fr> Date: Sun, 16 Apr 1995 00:54:04 GMT References: <1995Apr13.105804.5324@cam.ac.uk> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Apr13.105804.5324@cam.ac.uk>, bnovak@cam.ac.uk (Brian Novak) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- Kenji Nakamura "A soul is not exclusive to biology." Atari TT030 / AmigaOS 3.1 From brodriguez@uu.net Sun Apr 16 11:22:04 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!uu!brodriguez From: brodriguez@uu.net (Bastien Rodríguez) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr16.112204.3837@uu.net> Date: Sun, 16 Apr 1995 11:22:04 GMT References: <1995Apr13.105804.5324@cam.ac.uk> <1995Apr16.005404.6295@inria.fr> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: NewsWatcher 2.0b24 Lines: 9 In article <1995Apr16.005404.6295@inria.fr>, knakamura@inria.fr (Kenji Nakamura) writes: > PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? -- === Bastien Rodríguez === Dept of Electrical Engineering, UUNET Technologies, Falls Church VA "The hatch is open. Is anyone listening?" From thughes@unam.mx Mon Apr 17 07:45:04 1995 Path: ashpoly!cascade!bigsur!unam!thughes From: thughes@unam.mx (Tyler Hughes) Newsgroups: comp.sys.m68k Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Apr17.074504.5618@unam.mx> Date: Mon, 17 Apr 1995 07:45:04 GMT References: <1995Apr13.105804.5324@cam.ac.uk> <1995Apr13.215304.2139@purdue.edu> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Apr13.215304.2139@purdue.edu>, nfournier@purdue.edu (Natalia Fournier) 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! -- Tyler Hughes *PLONK* filter active for trolls. Atari TT030 - NetBSD 1.0