From fgirard@pacbell.net Sun Dec 08 06:19:21 1996
Path: ashpoly!cascade!bigsur!pacbell!fgirard
From: fgirard@pacbell.net (Fiona Girard)
Newsgroups: comp.sys.m68k
Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1996Dec08.061921.9559@pacbell.net>
Date: Sun, 08 Dec 1996 06:19:21 GMT
Organization: Pacific Bell Internet Services
NNTP-Posting-Host: pacbell.net
X-Newsreader: TIN [version 1.2 PL2]
Lines: 10

Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler.

The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1.
I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz.

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

-- 
Fiona Girard
Tape trading list upon request. SASE required for international mail.

From ksantos@kth.se Sun Dec 08 22:56:21 1996
Path: ashpoly!cascade!mxgate!coyoacan!kth!ksantos
From: ksantos@kth.se (Karen Santos)
Newsgroups: comp.sys.m68k
Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1996Dec08.225621.3406@kth.se>
Date: Sun, 08 Dec 1996 22:56:21 GMT
References: <1996Dec08.061921.9559@pacbell.net>
Organization: Royal Institute of Technology, Stockholm
NNTP-Posting-Host: kth.se
X-Newsreader: WinVN 0.99.5
Lines: 12

In article <1996Dec08.061921.9559@pacbell.net>, fgirard@pacbell.net (Fiona Girard) writes:
> Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler.
> The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1.

Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window.

Netscape 1.1 crashes when loading large preformatted text. Stick to rn or tin!

-- 
Karen Santos | ksantos@kth.se
PGP Key fingerprint: 605C 3994 6004 F06B
"Keep the channels open."

From mkowalski@cern.ch Mon Dec 09 18:19:21 1996
Path: ashpoly!cascade!brgate!saturno!cern!mkowalski
From: mkowalski@cern.ch (Marisol Kowalski)
Newsgroups: comp.sys.m68k
Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1996Dec09.181921.7561@cern.ch>
Date: Mon, 09 Dec 1996 18:19:21 GMT
References: <1996Dec08.061921.9559@pacbell.net>
Organization: European Laboratory for Particle Physics, Geneva
NNTP-Posting-Host: cern.ch
X-Newsreader: Netscape 1.1N
Lines: 10

In article <1996Dec08.061921.9559@pacbell.net>, fgirard@pacbell.net (Fiona Girard) writes:
> Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler.
> The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1.

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

-- 
=== Marisol Kowalski ===
Dept of Electrical Engineering, European Laboratory for Particle Physics, Geneva
"Hold for relay."

From achoi@panix.com Wed Dec 11 13:52:21 1996
Path: ashpoly!cascade!brgate!saturno!panix!achoi
From: achoi@panix.com (Andrei Choi)
Newsgroups: comp.sys.m68k
Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1996Dec11.135221.2964@panix.com>
Date: Wed, 11 Dec 1996 13:52:21 GMT
References: <1996Dec08.061921.9559@pacbell.net> <1996Dec09.181921.7561@cern.ch>
Organization: Public Access Unix of New York
NNTP-Posting-Host: panix.com
X-Newsreader: Netscape 1.1N
Lines: 9

In article <1996Dec09.181921.7561@cern.ch>, mkowalski@cern.ch (Marisol Kowalski) writes:
> Download failed on Aminet mirror. Can someone mail me an ADF floppy disk image?

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

-- 
=== Andrei Choi ===
Dept of Electrical Engineering, Public Access Unix of New York
"The hatch is open. Is anyone listening?"