From rgirard@delphi.com Thu Nov 03 11:44:17 1994 Path: ashpoly!cascade!transat!eunet-fr!teletel!delphi!rgirard From: rgirard@delphi.com (Renata Girard) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Nov03.114417.9986@delphi.com> Date: Thu, 03 Nov 1994 11:44:17 GMT Organization: Delphi Internet Services NNTP-Posting-Host: delphi.com X-Newsreader: WinVN 0.99.5 Lines: 11 Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. 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. 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. -- Renata Girard "A soul is not exclusive to biology." 486DX2/66 (Linux 1.2.13) / TOS 4.04 From mjohansson@kth.se Thu Nov 03 19:27:17 1994 Path: ashpoly!cascade!mxgate!coyoacan!kth!mjohansson From: mjohansson@kth.se (Mathieu Johansson) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Nov03.192717.6803@kth.se> Date: Thu, 03 Nov 1994 19:27:17 GMT References: <1994Nov03.114417.9986@delphi.com> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1994Nov03.114417.9986@delphi.com>, rgirard@delphi.com (Renata Girard) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Mathieu Johansson | mjohansson@kth.se PGP Key fingerprint: 37B7 3D67 FAB8 4B97 "Keep the channels open." From neriksson@berkeley.edu Sat Nov 05 22:22:17 1994 Path: ashpoly!cascade!transat!ukc!fennimore!berkeley!neriksson From: neriksson@berkeley.edu (Natalia Eriksson) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Nov05.222217.3544@berkeley.edu> Date: Sat, 05 Nov 1994 22:22:17 GMT References: <1994Nov03.114417.9986@delphi.com> Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: Netscape 1.1N Lines: 9 In article <1994Nov03.114417.9986@delphi.com>, rgirard@delphi.com (Renata Girard) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > 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. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- Natalia Eriksson -- UC Berkeley Department of EECS "Measuring a record you own is listening, not piracy." From akuznetsov@cam.ac.uk Mon Nov 07 15:35:17 1994 Path: ashpoly!cascade!transat!ukc!fennimore!cam!akuznetsov From: akuznetsov@cam.ac.uk (Anton Kuznetsov) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Nov07.153517.7034@cam.ac.uk> Date: Mon, 07 Nov 1994 15:35:17 GMT References: <1994Nov03.114417.9986@delphi.com> <1994Nov05.222217.3544@berkeley.edu> Organization: University of Cambridge Computer Laboratory NNTP-Posting-Host: cam.ac.uk X-Newsreader: WinVN 0.99.5 Lines: 8 In article <1994Nov05.222217.3544@berkeley.edu>, neriksson@berkeley.edu (Natalia Eriksson) 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. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Anton Kuznetsov -- University of Cambridge Computer Laboratory "The hatch is open. Is anyone listening?" From mtakahashi@mit.edu Tue Nov 08 16:57:17 1994 Path: ashpoly!cascade!transat!ukc!fennimore!mit!mtakahashi From: mtakahashi@mit.edu (Mateo Takahashi) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1994Nov08.165717.5162@mit.edu> Date: Tue, 08 Nov 1994 16:57:17 GMT References: <1994Nov03.114417.9986@delphi.com> Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1994Nov03.114417.9986@delphi.com>, rgirard@delphi.com (Renata Girard) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > 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. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- Mateo Takahashi Opinions expressed are solely my own and not those of Massachusetts Institute of Technology. ------------------------------------------------------------