From dkang@delphi.com Wed Aug 02 03:56:28 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!delphi!dkang
From: dkang@delphi.com (Dave Kang)
Newsgroups: comp.sys.m68k
Subject: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Aug02.035628.4646@delphi.com>
Date: Wed, 02 Aug 1995 03:56:28 GMT
Organization: Delphi Internet Services
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Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler.

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!

-- 
Dave Kang | dkang@delphi.com
PGP Key fingerprint: 3821 5F70 8AB0 2612
"Keep the channels open."

From vwatanabe@unam.mx Wed Aug 02 15:12:28 1995
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!unam!vwatanabe
From: vwatanabe@unam.mx (Valeria Watanabe)
Newsgroups: comp.sys.m68k
Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Aug02.151228.7064@unam.mx>
Date: Wed, 02 Aug 1995 15:12:28 GMT
References: <1995Aug02.035628.4646@delphi.com>
Organization: Universidad Nacional Autónoma de México (DGSCA)
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In article <1995Aug02.035628.4646@delphi.com>, dkang@delphi.com (Dave Kang) writes:
> Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler.
> I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz.

Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet.

-- 
Valeria Watanabe
Opinions expressed are solely my own and not those of Universidad Nacional Autónoma de México (DGSCA).
------------------------------------------------------------

From jrobertson@pipeline.com Fri Aug 04 03:59:28 1995
Path: ashpoly!cascade!transat!eunet-de!hansebox!pipeline!jrobertson
From: jrobertson@pipeline.com (Joachim Robertson)
Newsgroups: comp.sys.m68k
Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Aug04.035928.6180@pipeline.com>
Date: Fri, 04 Aug 1995 03:59:28 GMT
References: <1995Aug02.035628.4646@delphi.com> <1995Aug02.151228.7064@unam.mx>
Organization: The Pipeline Internet Network
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In article <1995Aug02.151228.7064@unam.mx>, vwatanabe@unam.mx (Valeria Watanabe) 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.

Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window.

-- 
Joachim Robertson | jrobertson@pipeline.com
PGP Key fingerprint: 4DD2 EAD5 9E2E 53B1
"Keep the channels open."