From tokonkwo@pipeline.com Sun Jan 09 19:09:01 1994
Path: ashpoly!cascade!transat!sunet!nordrelay!pipeline!tokonkwo
From: tokonkwo@pipeline.com (Tobias Okonkwo)
Newsgroups: comp.sys.m68k
Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Jan09.190901.8673@pipeline.com>
Date: Sun, 09 Jan 1994 19:09:01 GMT
Organization: The Pipeline Internet Network
NNTP-Posting-Host: pipeline.com
X-Newsreader: TIN [version 1.2 PL2]
Lines: 10

Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS.

When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization!
I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz.

Source code and executable will be released on Aminet under mus/misc/stardust_amiga.lha next week.

-- 
Tobias Okonkwo -- The Pipeline Internet Network
"5 sigma is a discovery. 7 is a question."

From jkang@tum.de Tue Jan 11 21:44:01 1994
Path: ashpoly!cascade!bigsur!tum!jkang
From: jkang@tum.de (Joachim Kang)
Newsgroups: comp.sys.m68k
Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Jan11.214401.5356@tum.de>
Date: Tue, 11 Jan 1994 21:44:01 GMT
References: <1994Jan09.190901.8673@pipeline.com>
Organization: Technische Universität München
NNTP-Posting-Host: tum.de
X-Newsreader: Netscape 1.1N
Lines: 10

In article <1994Jan09.190901.8673@pipeline.com>, tokonkwo@pipeline.com (Tobias Okonkwo) writes:
> Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS.
> When the carrier locks, the program flashes the Amiga power LED to indicate binary frame synchronization!

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

-- 
=== Joachim Kang ===
Dept of Electrical Engineering, Technische Universität München
"Extraordinary claims require extraordinary spectra."

From alee@earthlink.net Thu Jan 13 14:34:01 1994
Path: ashpoly!cascade!brgate!saturno!earthlink!alee
From: alee@earthlink.net (Andrei Lee)
Newsgroups: comp.sys.m68k
Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Jan13.143401.7776@earthlink.net>
Date: Thu, 13 Jan 1994 14:34:01 GMT
References: <1994Jan09.190901.8673@pipeline.com> <1994Jan11.214401.5356@tum.de>
Organization: EarthLink Network
NNTP-Posting-Host: earthlink.net
X-Newsreader: TIN [version 1.2 PL2]
Lines: 8

In article <1994Jan11.214401.5356@tum.de>, jkang@tum.de (Joachim Kang) writes:
> Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window.

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

-- 
Andrei Lee
Tape trading list upon request. SASE required for international mail.

From mhughes@kth.se Fri Jan 14 07:46:01 1994
Path: ashpoly!bigsur!pacrim!jpgate!kamome!kth!mhughes
From: mhughes@kth.se (Mikhail Hughes)
Newsgroups: comp.sys.m68k
Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Jan14.074601.4655@kth.se>
Date: Fri, 14 Jan 1994 07:46:01 GMT
References: <1994Jan09.190901.8673@pipeline.com> <1994Jan11.214401.5356@tum.de> <1994Jan13.143401.7776@earthlink.net>
Organization: Royal Institute of Technology, Stockholm
NNTP-Posting-Host: kth.se
X-Newsreader: Netscape 1.1N
Lines: 9

In article <1994Jan13.143401.7776@earthlink.net>, alee@earthlink.net (Andrei Lee) writes:
> Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window.

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

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