From trobertson@delphi.com Sun Jan 22 12:10:31 1995 Path: ashpoly!cascade!transat!ukc!fennimore!delphi!trobertson From: trobertson@delphi.com (Tobias Robertson) Newsgroups: comp.sys.m68k Subject: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jan22.121031.6757@delphi.com> Date: Sun, 22 Jan 1995 12:10:31 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. -- Tobias Robertson Opinions expressed are solely my own and not those of Delphi Internet Services. ------------------------------------------------------------ From hnilsson@rwth-aachen.de Tue Jan 24 01:16:31 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!rwth-aachen!hnilsson From: hnilsson@rwth-aachen.de (Hugo Nilsson) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jan24.011631.9004@rwth-aachen.de> Date: Tue, 24 Jan 1995 01:16:31 GMT References: <1995Jan22.121031.6757@delphi.com> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1995Jan22.121031.6757@delphi.com>, trobertson@delphi.com (Tobias Robertson) 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. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- Hugo Nilsson SupraFAXModem 28.8 @ 33,600 bps "Do not worship the copy." From dokonkwo@u-tokyo.ac.jp Wed Jan 25 05:45:31 1995 Path: ashpoly!cascade!transat!eunet-fr!teletel!u-tokyo!dokonkwo From: dokonkwo@u-tokyo.ac.jp (Diego Okonkwo) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jan25.054531.5082@u-tokyo.ac.jp> Date: Wed, 25 Jan 1995 05:45:31 GMT References: <1995Jan22.121031.6757@delphi.com> <1995Jan24.011631.9004@rwth-aachen.de> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: Netscape 1.1N Lines: 11 In article <1995Jan24.011631.9004@rwth-aachen.de>, hnilsson@rwth-aachen.de (Hugo Nilsson) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. Unsubscribe me from this list! (Wait, this is Usenet, never mind). -- === Diego Okonkwo === Dept of Electrical Engineering, University of Tokyo Department of Information Science "Measuring a record you own is listening, not piracy." From mkuznetsov@uu.net Thu Jan 26 07:06:31 1995 Path: ashpoly!bigsur!pacrim!krgate!eunha!uu!mkuznetsov From: mkuznetsov@uu.net (Morag Kuznetsov) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jan26.070631.3586@uu.net> Date: Thu, 26 Jan 1995 07:06:31 GMT References: <1995Jan22.121031.6757@delphi.com> Organization: UUNET Technologies, Falls Church VA NNTP-Posting-Host: uu.net X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Jan22.121031.6757@delphi.com>, trobertson@delphi.com (Tobias Robertson) 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! -- Morag Kuznetsov Practical Peripherals 14.4 @ 9600 Telebit bps "Measuring a record you own is listening, not piracy." From hchoi@mindspring.com Sat Jan 28 06:13:31 1995 Path: ashpoly!cascade!transat!ukc!fennimore!mindspring!hchoi From: hchoi@mindspring.com (Heather Choi) Newsgroups: comp.sys.m68k Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jan28.061331.8040@mindspring.com> Date: Sat, 28 Jan 1995 06:13:31 GMT References: <1995Jan22.121031.6757@delphi.com> <1995Jan24.011631.9004@rwth-aachen.de> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: WinVN 0.99.5 Lines: 10 In article <1995Jan24.011631.9004@rwth-aachen.de>, hnilsson@rwth-aachen.de (Hugo Nilsson) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. > Unsubscribe me from this list! (Wait, this is Usenet, never mind). Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- === Heather Choi === Dept of Electrical Engineering, MindSpring Enterprises "Marcus is not one man."