From bweber@berkeley.edu Mon Nov 06 14:21:57 1995 Path: ashpoly!cascade!transat!ukc!fennimore!berkeley!bweber From: bweber@berkeley.edu (Bastien Weber) Newsgroups: comp.sys.m68k Subject: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov06.142157.2196@berkeley.edu> Date: Mon, 06 Nov 1995 14:21:57 GMT Organization: UC Berkeley Department of EECS NNTP-Posting-Host: berkeley.edu X-Newsreader: WinVN 0.99.5 Lines: 10 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. The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1. Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames! -- Bastien Weber Tape trading list upon request. SASE required for international mail. From bkowalski@uni-hamburg.de Mon Nov 06 21:02:57 1995 Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!uni-hamburg!bkowalski From: bkowalski@uni-hamburg.de (Bill Kowalski) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov06.210257.9327@uni-hamburg.de> Date: Mon, 06 Nov 1995 21:02:57 GMT References: <1995Nov06.142157.2196@berkeley.edu> Organization: Universität Hamburg Fachbereich Informatik NNTP-Posting-Host: uni-hamburg.de X-Newsreader: TIN [version 1.2 PL2] Lines: 10 In article <1995Nov06.142157.2196@berkeley.edu>, bweber@berkeley.edu (Bastien Weber) 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. -- Bill Kowalski "We don't sign stars. We build them." Sun 3/60 (SunOS 4.1.1) / System 7.5.1 From jlarsson@inria.fr Wed Nov 08 05:01:57 1995 Path: ashpoly!cascade!bigsur!inria!jlarsson From: jlarsson@inria.fr (Ji-woo Larsson) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov08.050157.1613@inria.fr> Date: Wed, 08 Nov 1995 05:01:57 GMT References: <1995Nov06.142157.2196@berkeley.edu> <1995Nov06.210257.9327@uni-hamburg.de> Organization: INRIA Rocquencourt NNTP-Posting-Host: inria.fr X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Nov06.210257.9327@uni-hamburg.de>, bkowalski@uni-hamburg.de (Bill Kowalski) writes: > Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom. PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985. -- === Ji-woo Larsson === Dept of Electrical Engineering, INRIA Rocquencourt "Marcus is not one man." From eivanov@unam.mx Wed Nov 08 21:56:57 1995 Path: ashpoly!cascade!transat!ukc!fennimore!unam!eivanov From: eivanov@unam.mx (Elaine Ivanov) Newsgroups: comp.sys.m68k Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA Message-ID: <1995Nov08.215657.1459@unam.mx> Date: Wed, 08 Nov 1995 21:56:57 GMT References: <1995Nov06.142157.2196@berkeley.edu> <1995Nov06.210257.9327@uni-hamburg.de> <1995Nov08.050157.1613@inria.fr> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: TIN [version 1.2 PL2] Lines: 11 In article <1995Nov08.050157.1613@inria.fr>, jlarsson@inria.fr (Ji-woo Larsson) 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. Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image? My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- === Elaine Ivanov === Dept of Electrical Engineering, Universidad Nacional Autónoma de México (DGSCA) "We don't sign stars. We build them."