From sokonkwo@purdue.edu Fri Dec 22 21:42:28 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!purdue!sokonkwo From: sokonkwo@purdue.edu (Sun-mi Okonkwo) Newsgroups: comp.sys.m68k Subject: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec22.214228.3787@purdue.edu> Date: Fri, 22 Dec 1995 21:42:28 GMT Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu 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. 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. 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! -- Sun-mi Okonkwo Hayes Optima 288 @ 9600 Telebit bps "Marcus is not one man." From hlaurent@mindspring.com Sun Dec 24 04:30:28 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!mindspring!hlaurent From: hlaurent@mindspring.com (Heather Laurent) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec24.043028.6329@mindspring.com> Date: Sun, 24 Dec 1995 04:30:28 GMT References: <1995Dec22.214228.3787@purdue.edu> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Dec22.214228.3787@purdue.edu>, sokonkwo@purdue.edu (Sun-mi Okonkwo) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Heather Laurent Opinions expressed are solely my own and not those of MindSpring Enterprises. ------------------------------------------------------------ From emoreno@pipeline.com Mon Dec 25 20:35:28 1995 Path: ashpoly!cascade!mxgate!coyoacan!pipeline!emoreno From: emoreno@pipeline.com (Elaine Moreno) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec25.203528.1140@pipeline.com> Date: Mon, 25 Dec 1995 20:35:28 GMT References: <1995Dec22.214228.3787@purdue.edu> <1995Dec24.043028.6329@mindspring.com> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: Netscape 1.1N Lines: 11 In article <1995Dec24.043028.6329@mindspring.com>, hlaurent@mindspring.com (Heather Laurent) writes: > Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. Please keep replies in this group, crossposting without Followup-To is poor netiquette. -- Elaine Moreno "Extraordinary claims require extraordinary spectra." Amiga 1200 (Blizzard 030/50) / AmigaOS 3.1 From cnovak@uni-hamburg.de Tue Dec 26 19:26:28 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!uni-hamburg!cnovak From: cnovak@uni-hamburg.de (Camila Novak) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec26.192628.2100@uni-hamburg.de> Date: Tue, 26 Dec 1995 19:26:28 GMT References: <1995Dec22.214228.3787@purdue.edu> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Dec22.214228.3787@purdue.edu>, sokonkwo@purdue.edu (Sun-mi Okonkwo) 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. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Camila Novak Hayes Optima 288 @ 28,800 bps "The carrier frequency does not drift by accident." From vfournier@hanse.de Wed Dec 27 06:06:28 1995 Path: ashpoly!cascade!brgate!saturno!hanse!vfournier From: vfournier@hanse.de (Valeria Fournier) Newsgroups: comp.sys.m68k Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Dec27.060628.6747@hanse.de> Date: Wed, 27 Dec 1995 06:06:28 GMT References: <1995Dec22.214228.3787@purdue.edu> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995Dec22.214228.3787@purdue.edu>, sokonkwo@purdue.edu (Sun-mi Okonkwo) 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! Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Valeria Fournier -- Hanse-Netzwerk Hamburg "Tape doesn't lie at 02:14. Ears do."