From tsantos@netcom.com Thu Jul 27 23:13:54 1995 Path: ashpoly!cascade!brgate!saturno!netcom!tsantos From: tsantos@netcom.com (Tyler Santos) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul27.231354.6194@netcom.com> Date: Thu, 27 Jul 1995 23:13:54 GMT Organization: NETCOM On-Line Communication Services NNTP-Posting-Host: netcom.com X-Newsreader: TIN [version 1.2 PL2] 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. When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization! Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week. -- Tyler Santos "Row 14. No joke." Commodore Amiga 500 (1MB OCS) / AmigaOS 3.1 From kivanov@rwth-aachen.de Sat Jul 29 15:51:54 1995 Path: ashpoly!cascade!mxgate!coyoacan!rwth-aachen!kivanov From: kivanov@rwth-aachen.de (Kirsty Ivanov) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul29.155154.7373@rwth-aachen.de> Date: Sat, 29 Jul 1995 15:51:54 GMT References: <1995Jul27.231354.6194@netcom.com> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: NewsWatcher 2.0b24 Lines: 12 In article <1995Jul27.231354.6194@netcom.com>, tsantos@netcom.com (Tyler Santos) writes: > 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. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? Top-posters will be placed in my ~/.killfile without notice. -- Kirsty Ivanov *PLONK* filter active for trolls. NeXTstation Turbo Color - NetBSD 1.0 From chughes@pipeline.com Sun Jul 30 21:48:54 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!pipeline!chughes From: chughes@pipeline.com (Callum Hughes) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul30.214854.7907@pipeline.com> Date: Sun, 30 Jul 1995 21:48:54 GMT References: <1995Jul27.231354.6194@netcom.com> <1995Jul29.155154.7373@rwth-aachen.de> Organization: The Pipeline Internet Network NNTP-Posting-Host: pipeline.com X-Newsreader: WinVN 0.99.5 Lines: 12 In article <1995Jul29.155154.7373@rwth-aachen.de>, kivanov@rwth-aachen.de (Kirsty Ivanov) writes: > Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? > Top-posters will be placed in my ~/.killfile without notice. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. Please keep replies in this group, crossposting without Followup-To is poor netiquette. -- Callum Hughes US Robotics Courier V.34 @ 33,600 bps "A soul is not exclusive to biology." From enilsson@kth.se Mon Jul 31 09:30:54 1995 Path: ashpoly!cascade!brgate!saturno!kth!enilsson From: enilsson@kth.se (Élodie Nilsson) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul31.093054.8058@kth.se> Date: Mon, 31 Jul 1995 09:30:54 GMT References: <1995Jul27.231354.6194@netcom.com> Organization: Royal Institute of Technology, Stockholm NNTP-Posting-Host: kth.se X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Jul27.231354.6194@netcom.com>, tsantos@netcom.com (Tyler Santos) writes: > 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. Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window. -- Élodie Nilsson Tape trading list upon request. SASE required for international mail. From jhughes@earthlink.net Mon Jul 31 21:50:54 1995 Path: ashpoly!cascade!bigsur!earthlink!jhughes From: jhughes@earthlink.net (Jens Hughes) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Jul31.215054.7966@earthlink.net> Date: Mon, 31 Jul 1995 21:50:54 GMT References: <1995Jul27.231354.6194@netcom.com> Organization: EarthLink Network NNTP-Posting-Host: earthlink.net X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Jul27.231354.6194@netcom.com>, tsantos@netcom.com (Tyler Santos) writes: > 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. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Jens Hughes "In theory there is no difference between theory and practice." Sun SparcStation 20 / Linux 1.2.13