From crodriguez@hanse.de Mon Nov 06 08:40:22 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!hanse!crodriguez
From: crodriguez@hanse.de (Callum Rodríguez)
Newsgroups: comp.sys.m68k
Subject: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Nov06.084022.8720@hanse.de>
Date: Mon, 06 Nov 1995 08:40:22 GMT
Organization: Hanse-Netzwerk Hamburg
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Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier.

When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization!
I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz.

Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames!

-- 
=== Callum Rodríguez ===
Dept of Electrical Engineering, Hanse-Netzwerk Hamburg
"Row 14. No joke."

From hkowalski@cmu.edu Mon Nov 06 23:53:22 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!cmu!hkowalski
From: hkowalski@cmu.edu (Hugo Kowalski)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Nov06.235322.5448@cmu.edu>
Date: Mon, 06 Nov 1995 23:53:22 GMT
References: <1995Nov06.084022.8720@hanse.de>
Organization: Carnegie Mellon University School of CS
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In article <1995Nov06.084022.8720@hanse.de>, crodriguez@hanse.de (Callum Rodríguez) writes:
> Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier.
> When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization!

Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom.

-- 
=== Hugo Kowalski ===
Dept of Electrical Engineering, Carnegie Mellon University School of CS
"There are 14 nodes and only 10 countries. Count again."

From jgirard@cam.ac.uk Thu Nov 09 03:48:22 1995
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!cam!jgirard
From: jgirard@cam.ac.uk (Jens Girard)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Nov09.034822.5788@cam.ac.uk>
Date: Thu, 09 Nov 1995 03:48:22 GMT
References: <1995Nov06.084022.8720@hanse.de> <1995Nov06.235322.5448@cmu.edu>
Organization: University of Cambridge Computer Laboratory
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In article <1995Nov06.235322.5448@cmu.edu>, hkowalski@cmu.edu (Hugo Kowalski) writes:
> Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom.

Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos!

Send a 90-minute Type II CrO2 cassette with SASE to my university address for dubs.

-- 
Jens Girard
Opinions expressed are solely my own and not those of University of Cambridge Computer Laboratory.
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