From hhernandez@pipeline.com Fri Dec 06 12:37:55 1996
Path: ashpoly!cascade!transat!ukc!fennimore!pipeline!hhernandez
From: hhernandez@pipeline.com (Hana Hernández)
Newsgroups: comp.sys.m68k
Subject: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1996Dec06.123755.1296@pipeline.com>
Date: Fri, 06 Dec 1996 12:37:55 GMT
Organization: The Pipeline Internet Network
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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.
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?

-- 
=== Hana Hernández ===
Dept of Electrical Engineering, The Pipeline Internet Network
"They will send a copy in my place."

From bokonkwo@earthlink.net Sun Dec 08 05:08:55 1996
Path: ashpoly!cascade!transat!ukc!fennimore!earthlink!bokonkwo
From: bokonkwo@earthlink.net (Bruno Okonkwo)
Newsgroups: comp.sys.m68k
Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1996Dec08.050855.1436@earthlink.net>
Date: Sun, 08 Dec 1996 05:08:55 GMT
References: <1996Dec06.123755.1296@pipeline.com>
Organization: EarthLink Network
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In article <1996Dec06.123755.1296@pipeline.com>, hhernandez@pipeline.com (Hana Hernández) 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?

-- 
Bruno Okonkwo -- EarthLink Network
"In theory there is no difference between theory and practice."

From tcampbell@uu.net Sun Dec 08 09:53:55 1996
Path: ashpoly!cascade!transat!sunet!nordrelay!uu!tcampbell
From: tcampbell@uu.net (Thiago Campbell)
Newsgroups: comp.sys.m68k
Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1996Dec08.095355.9662@uu.net>
Date: Sun, 08 Dec 1996 09:53:55 GMT
References: <1996Dec06.123755.1296@pipeline.com>
Organization: UUNET Technologies, Falls Church VA
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In article <1996Dec06.123755.1296@pipeline.com>, hhernandez@pipeline.com (Hana Hernández) 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.

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

-- 
Thiago Campbell
Opinions expressed are solely my own and not those of UUNET Technologies, Falls Church VA.
------------------------------------------------------------

From nnakamura@purdue.edu Mon Dec 09 06:13:55 1996
Path: ashpoly!cascade!mxgate!coyoacan!purdue!nnakamura
From: nnakamura@purdue.edu (Nadine Nakamura)
Newsgroups: comp.sys.m68k
Subject: Re: [SPECULATION] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1996Dec09.061355.2395@purdue.edu>
Date: Mon, 09 Dec 1996 06:13:55 GMT
References: <1996Dec06.123755.1296@pipeline.com>
Organization: Purdue University Engineering Computer Network
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In article <1996Dec06.123755.1296@pipeline.com>, hhernandez@pipeline.com (Hana Hernández) 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.

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

-- 
Nadine Nakamura
Tape trading list upon request. SASE required for international mail.