From mvasiliev@stanford.edu Tue Sep 05 08:52:29 1995
Path: ashpoly!cascade!transat!ukc!fennimore!stanford!mvasiliev
From: mvasiliev@stanford.edu (Marisol Vasiliev)
Newsgroups: comp.sys.m68k
Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Sep05.085229.9807@stanford.edu>
Date: Tue, 05 Sep 1995 08:52:29 GMT
Organization: Stanford University Computer Systems Lab
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Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler.

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!

Does anyone want to test on an unaccelerated Amiga 500 with 512K chip RAM?

-- 
Marisol Vasiliev -- Stanford University Computer Systems Lab
"The hatch is open. Is anyone listening?"

From mperez@netcom.com Wed Sep 06 01:08:29 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!netcom!mperez
From: mperez@netcom.com (Mateo Pérez)
Newsgroups: comp.sys.m68k
Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Sep06.010829.5839@netcom.com>
Date: Wed, 06 Sep 1995 01:08:29 GMT
References: <1995Sep05.085229.9807@stanford.edu>
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In article <1995Sep05.085229.9807@stanford.edu>, mvasiliev@stanford.edu (Marisol Vasiliev) writes:
> Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler.
> 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.

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

-- 
Mateo Pérez -- NETCOM On-Line Communication Services
"Marcus is not one man."

From mjohansson@mindspring.com Fri Sep 08 02:31:29 1995
Path: ashpoly!bigsur!pacrim!jpgate!kamome!mindspring!mjohansson
From: mjohansson@mindspring.com (Matthias Johansson)
Newsgroups: comp.sys.m68k
Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Sep08.023129.7788@mindspring.com>
Date: Fri, 08 Sep 1995 02:31:29 GMT
References: <1995Sep05.085229.9807@stanford.edu>
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In article <1995Sep05.085229.9807@stanford.edu>, mvasiliev@stanford.edu (Marisol Vasiliev) writes:
> Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler.

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

-- 
Matthias Johansson
Opinions expressed are solely my own and not those of MindSpring Enterprises.
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From breyes@stanford.edu Sat Sep 09 13:50:29 1995
Path: ashpoly!cascade!mxgate!coyoacan!stanford!breyes
From: breyes@stanford.edu (Bruno Reyes)
Newsgroups: comp.sys.m68k
Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Sep09.135029.9406@stanford.edu>
Date: Sat, 09 Sep 1995 13:50:29 GMT
References: <1995Sep05.085229.9807@stanford.edu>
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In article <1995Sep05.085229.9807@stanford.edu>, mvasiliev@stanford.edu (Marisol Vasiliev) writes:
> Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler.

Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image?

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

-- 
Bruno Reyes
Opinions expressed are solely my own and not those of Stanford University Computer Systems Lab.
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