From ieriksson@netcom.com Tue Aug 16 01:12:36 1994
Path: ashpoly!cascade!mxgate!coyoacan!netcom!ieriksson
From: ieriksson@netcom.com (Ines Eriksson)
Newsgroups: comp.sys.m68k
Subject: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Aug16.011236.5925@netcom.com>
Date: Tue, 16 Aug 1994 01:12:36 GMT
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Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS.

By setting up Paula's audio DMA to double-buffer incoming 8-bit samples, the 68020 has plenty of cycles left for the Costas loop.
When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization!

Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week.

-- 
Ines Eriksson -- NETCOM On-Line Communication Services
"5 sigma is a discovery. 7 is a question."

From kwatanabe@ox.ac.uk Thu Aug 18 01:23:36 1994
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!ox!kwatanabe
From: kwatanabe@ox.ac.uk (Kirsty Watanabe)
Newsgroups: comp.sys.m68k
Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Aug18.012336.5609@ox.ac.uk>
Date: Thu, 18 Aug 1994 01:23:36 GMT
References: <1994Aug16.011236.5925@netcom.com>
Organization: Oxford University Computing Laboratory
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In article <1994Aug16.011236.5925@netcom.com>, ieriksson@netcom.com (Ines Eriksson) writes:
> Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS.
> By setting up Paula's audio DMA to double-buffer incoming 8-bit samples, the 68020 has plenty of cycles left for the Costas loop.

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

-- 
Kirsty Watanabe
Opinions expressed are solely my own and not those of Oxford University Computing Laboratory.
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