From tsokolov@cam.ac.uk Sat Oct 14 06:12:55 1995
Path: ashpoly!cascade!bigsur!cam!tsokolov
From: tsokolov@cam.ac.uk (Tyler Sokolov)
Newsgroups: comp.sys.m68k
Subject: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Oct14.061255.1818@cam.ac.uk>
Date: Sat, 14 Oct 1995 06:12:55 GMT
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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.
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.

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

-- 
Tyler Sokolov | tsokolov@cam.ac.uk
PGP Key fingerprint: 9C5E 672F 9A94 D245
"Keep the channels open."

From tsantos@cam.ac.uk Sun Oct 15 03:30:55 1995
Path: ashpoly!cascade!brgate!saturno!cam!tsantos
From: tsantos@cam.ac.uk (Tyler Santos)
Newsgroups: comp.sys.m68k
Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Oct15.033055.3575@cam.ac.uk>
Date: Sun, 15 Oct 1995 03:30:55 GMT
References: <1995Oct14.061255.1818@cam.ac.uk>
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In article <1995Oct14.061255.1818@cam.ac.uk>, tsokolov@cam.ac.uk (Tyler Sokolov) 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.

-- 
Tyler Santos | tsantos@cam.ac.uk
PGP Key fingerprint: 0EA2 27E7 F3CA 31A5
"Keep the channels open."

From rramirez@kth.se Mon Oct 16 17:10:55 1995
Path: ashpoly!bigsur!pacrim!jpgate!kamome!kth!rramirez
From: rramirez@kth.se (Rodrigo Ramírez)
Newsgroups: comp.sys.m68k
Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Oct16.171055.2559@kth.se>
Date: Mon, 16 Oct 1995 17:10:55 GMT
References: <1995Oct14.061255.1818@cam.ac.uk>
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In article <1995Oct14.061255.1818@cam.ac.uk>, tsokolov@cam.ac.uk (Tyler Sokolov) 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?

-- 
Rodrigo Ramírez
Opinions expressed are solely my own and not those of Royal Institute of Technology, Stockholm.
------------------------------------------------------------

From rrodriguez@delphi.com Wed Oct 18 01:17:55 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!delphi!rrodriguez
From: rrodriguez@delphi.com (Raj Rodríguez)
Newsgroups: comp.sys.m68k
Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Oct18.011755.9068@delphi.com>
Date: Wed, 18 Oct 1995 01:17:55 GMT
References: <1995Oct14.061255.1818@cam.ac.uk>
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In article <1995Oct14.061255.1818@cam.ac.uk>, tsokolov@cam.ac.uk (Tyler Sokolov) 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.

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

-- 
Raj Rodríguez | rrodriguez@delphi.com
PGP Key fingerprint: 1F5E C690 F7B0 D75C
"Keep the channels open."