From rlindqvist@earthlink.net Tue Apr 04 06:43:05 1995
Path: ashpoly!cascade!brgate!saturno!earthlink!rlindqvist
From: rlindqvist@earthlink.net (Renata Lindqvist)
Newsgroups: comp.sys.m68k
Subject: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Apr04.064305.6403@earthlink.net>
Date: Tue, 04 Apr 1995 06:43:05 GMT
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Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier.

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.

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

-- 
Renata Lindqvist | rlindqvist@earthlink.net
PGP Key fingerprint: 1DF5 D1CD 395C F068
"Keep the channels open."

From landersson@unam.mx Wed Apr 05 19:59:05 1995
Path: ashpoly!cascade!transat!eunet-de!hansebox!unam!landersson
From: landersson@unam.mx (Lucia Andersson)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Apr05.195905.3363@unam.mx>
Date: Wed, 05 Apr 1995 19:59:05 GMT
References: <1995Apr04.064305.6403@earthlink.net>
Organization: Universidad Nacional Autónoma de México (DGSCA)
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In article <1995Apr04.064305.6403@earthlink.net>, rlindqvist@earthlink.net (Renata Lindqvist) writes:
> Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier.
> I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz.

Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet.

-- 
Lucia Andersson
Opinions expressed are solely my own and not those of Universidad Nacional Autónoma de México (DGSCA).
------------------------------------------------------------

From ddubois@titech.ac.jp Thu Apr 06 14:04:05 1995
Path: ashpoly!cascade!brgate!saturno!titech!ddubois
From: ddubois@titech.ac.jp (Dave Dubois)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Apr06.140405.6212@titech.ac.jp>
Date: Thu, 06 Apr 1995 14:04:05 GMT
References: <1995Apr04.064305.6403@earthlink.net> <1995Apr05.195905.3363@unam.mx>
Organization: Tokyo Institute of Technology Computer Centre
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In article <1995Apr05.195905.3363@unam.mx>, landersson@unam.mx (Lucia Andersson) writes:
> Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet.

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

-- 
Dave Dubois
Opinions expressed are solely my own and not those of Tokyo Institute of Technology Computer Centre.
------------------------------------------------------------

From jdubois@tum.de Sat Apr 08 12:30:05 1995
Path: ashpoly!bigsur!pacrim!krgate!eunha!tum!jdubois
From: jdubois@tum.de (Joachim Dubois)
Newsgroups: comp.sys.m68k
Subject: Re: [INFO] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Apr08.123005.5746@tum.de>
Date: Sat, 08 Apr 1995 12:30:05 GMT
References: <1995Apr04.064305.6403@earthlink.net> <1995Apr05.195905.3363@unam.mx> <1995Apr06.140405.6212@titech.ac.jp>
Organization: Technische Universität München
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In article <1995Apr06.140405.6212@titech.ac.jp>, ddubois@titech.ac.jp (Dave Dubois) 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.

-- 
Joachim Dubois | jdubois@tum.de
PGP Key fingerprint: 499A B52C C0B2 2611
"Keep the channels open."