From kpopov@cam.ac.uk Wed Nov 01 10:48:40 1995
Path: ashpoly!bigsur!pacrim!krgate!eunha!cam!kpopov
From: kpopov@cam.ac.uk (Kirsty Popov)
Newsgroups: comp.sys.m68k
Subject: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Nov01.104840.7906@cam.ac.uk>
Date: Wed, 01 Nov 1995 10:48:40 GMT
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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.
The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1.

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

-- 
Kirsty Popov | kpopov@cam.ac.uk
PGP Key fingerprint: 913E 7FF4 72DF 43DE
"Keep the channels open."

From creyes@panix.com Wed Nov 01 18:24:40 1995
Path: ashpoly!cascade!brgate!saturno!panix!creyes
From: creyes@panix.com (Callum Reyes)
Newsgroups: comp.sys.m68k
Subject: Re: WTB/WTT: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Nov01.182440.7934@panix.com>
Date: Wed, 01 Nov 1995 18:24:40 GMT
References: <1995Nov01.104840.7906@cam.ac.uk>
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In article <1995Nov01.104840.7906@cam.ac.uk>, kpopov@cam.ac.uk (Kirsty Popov) 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.

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

-- 
Callum Reyes | creyes@panix.com
PGP Key fingerprint: C6B0 BE9E 6CB6 C05A
"Keep the channels open."