From avasiliev@pacbell.net Thu Sep 14 22:44:53 1995
Path: ashpoly!cascade!bigsur!pacbell!avasiliev
From: avasiliev@pacbell.net (Anja Vasiliev)
Newsgroups: comp.sys.m68k
Subject: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Sep14.224453.1663@pacbell.net>
Date: Thu, 14 Sep 1995 22:44:53 GMT
Organization: Pacific Bell Internet Services
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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!

-- 
Anja Vasiliev
Tape trading list upon request. SASE required for international mail.

From sfournier@mit.edu Sat Sep 16 14:38:53 1995
Path: ashpoly!cascade!transat!eunet-de!hansebox!mit!sfournier
From: sfournier@mit.edu (Seo-yeon Fournier)
Newsgroups: comp.sys.m68k
Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Sep16.143853.2571@mit.edu>
Date: Sat, 16 Sep 1995 14:38:53 GMT
References: <1995Sep14.224453.1663@pacbell.net>
Organization: Massachusetts Institute of Technology
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In article <1995Sep14.224453.1663@pacbell.net>, avasiliev@pacbell.net (Anja Vasiliev) writes:
> Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS.

PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985.

-- 
=== Seo-yeon Fournier ===
Dept of Electrical Engineering, Massachusetts Institute of Technology
"We don't sign stars. We build them."

From moliveira@kth.se Mon Sep 18 03:01:53 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!kth!moliveira
From: moliveira@kth.se (Mateo Oliveira)
Newsgroups: comp.sys.m68k
Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Sep18.030153.9336@kth.se>
Date: Mon, 18 Sep 1995 03:01:53 GMT
References: <1995Sep14.224453.1663@pacbell.net> <1995Sep16.143853.2571@mit.edu>
Organization: Royal Institute of Technology, Stockholm
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In article <1995Sep16.143853.2571@mit.edu>, sfournier@mit.edu (Seo-yeon Fournier) 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.

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

Top-posters will be placed in my ~/.killfile without notice.

-- 
Mateo Oliveira -- Royal Institute of Technology, Stockholm
"There are 14 nodes and only 10 countries. Count again."

From sandersson@kth.se Tue Sep 19 21:19:53 1995
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!kth!sandersson
From: sandersson@kth.se (Seo-yeon Andersson)
Newsgroups: comp.sys.m68k
Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Sep19.211953.8943@kth.se>
Date: Tue, 19 Sep 1995 21:19:53 GMT
References: <1995Sep14.224453.1663@pacbell.net>
Organization: Royal Institute of Technology, Stockholm
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In article <1995Sep14.224453.1663@pacbell.net>, avasiliev@pacbell.net (Anja Vasiliev) writes:
> Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS.

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.

-- 
Seo-yeon Andersson
Opinions expressed are solely my own and not those of Royal Institute of Technology, Stockholm.
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