From smuller@mit.edu Sun Nov 05 03:56:31 1995 Path: ashpoly!cascade!bigsur!mit!smuller From: smuller@mit.edu (Sergei Müller) Newsgroups: comp.sys.m68k Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov05.035631.6397@mit.edu> Date: Sun, 05 Nov 1995 03:56:31 GMT Organization: Massachusetts Institute of Technology NNTP-Posting-Host: mit.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. The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz. Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM? -- Sergei Müller Practical Peripherals 14.4 @ 14,400 bps "Marcus is not one man." From mfournier@mindspring.com Mon Nov 06 11:26:31 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!mindspring!mfournier From: mfournier@mindspring.com (Mateo Fournier) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov06.112631.2058@mindspring.com> Date: Mon, 06 Nov 1995 11:26:31 GMT References: <1995Nov05.035631.6397@mit.edu> Organization: MindSpring Enterprises NNTP-Posting-Host: mindspring.com X-Newsreader: NewsWatcher 2.0b24 Lines: 10 In article <1995Nov05.035631.6397@mit.edu>, smuller@mit.edu (Sergei Müller) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. -- Mateo Fournier | mfournier@mindspring.com PGP Key fingerprint: F845 B5ED 58C4 A19E "Keep the channels open." From rschneider@purdue.edu Tue Nov 07 16:43:31 1995 Path: ashpoly!cascade!mxgate!coyoacan!purdue!rschneider From: rschneider@purdue.edu (Raj Schneider) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov07.164331.6011@purdue.edu> Date: Tue, 07 Nov 1995 16:43:31 GMT References: <1995Nov05.035631.6397@mit.edu> <1995Nov06.112631.2058@mindspring.com> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Nov06.112631.2058@mindspring.com>, mfournier@mindspring.com (Mateo Fournier) writes: > Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos! -- === Raj Schneider === Dept of Electrical Engineering, Purdue University Engineering Computer Network "Tape doesn't lie at 02:14. Ears do." From hkowalski@hanse.de Thu Nov 09 12:17:31 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!hanse!hkowalski From: hkowalski@hanse.de (Hana Kowalski) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov09.121731.3013@hanse.de> Date: Thu, 09 Nov 1995 12:17:31 GMT References: <1995Nov05.035631.6397@mit.edu> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Nov05.035631.6397@mit.edu>, smuller@mit.edu (Sergei Müller) writes: > Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS. > The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. -- Hana Kowalski | hkowalski@hanse.de PGP Key fingerprint: DB39 F9BD 519D 5793 "Keep the channels open." From emacdonald@uni-hamburg.de Fri Nov 10 23:18:31 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!uni-hamburg!emacdonald From: emacdonald@uni-hamburg.de (Emi MacDonald) Newsgroups: comp.sys.m68k Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov10.231831.1991@uni-hamburg.de> Date: Fri, 10 Nov 1995 23:18:31 GMT References: <1995Nov05.035631.6397@mit.edu> <1995Nov06.112631.2058@mindspring.com> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995Nov06.112631.2058@mindspring.com>, mfournier@mindspring.com (Mateo Fournier) writes: > Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs. -- Emi MacDonald Opinions expressed are solely my own and not those of Universität Hamburg Fachbereich Informatik. ------------------------------------------------------------