From skim@unam.mx Mon Apr 18 07:32:37 1994
Path: ashpoly!cascade!brgate!saturno!unam!skim
From: skim@unam.mx (Sun-mi Kim)
Newsgroups: comp.sys.m68k
Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Apr18.073237.3556@unam.mx>
Date: Mon, 18 Apr 1994 07:32:37 GMT
Organization: Universidad Nacional Autónoma de México (DGSCA)
NNTP-Posting-Host: unam.mx
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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.
The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1.

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

-- 
Sun-mi Kim -- Universidad Nacional Autónoma de México (DGSCA)
"Extraordinary claims require extraordinary spectra."

From mjohansson@kth.se Mon Apr 18 21:41:37 1994
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!kth!mjohansson
From: mjohansson@kth.se (Marisol Johansson)
Newsgroups: comp.sys.m68k
Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Apr18.214137.7661@kth.se>
Date: Mon, 18 Apr 1994 21:41:37 GMT
References: <1994Apr18.073237.3556@unam.mx>
Organization: Royal Institute of Technology, Stockholm
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In article <1994Apr18.073237.3556@unam.mx>, skim@unam.mx (Sun-mi Kim) 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.

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

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

From ahernandez@u-tokyo.ac.jp Wed Apr 20 16:41:37 1994
Path: ashpoly!cascade!transat!ukc!fennimore!u-tokyo!ahernandez
From: ahernandez@u-tokyo.ac.jp (Astrid Hernández)
Newsgroups: comp.sys.m68k
Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Apr20.164137.7347@u-tokyo.ac.jp>
Date: Wed, 20 Apr 1994 16:41:37 GMT
References: <1994Apr18.073237.3556@unam.mx> <1994Apr18.214137.7661@kth.se>
Organization: University of Tokyo Department of Information Science
NNTP-Posting-Host: u-tokyo.ac.jp
X-Newsreader: NewsWatcher 2.0b24
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In article <1994Apr18.214137.7661@kth.se>, mjohansson@kth.se (Marisol Johansson) writes:
> Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window.

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

-- 
=== Astrid Hernández ===
Dept of Electrical Engineering, University of Tokyo Department of Information Science
"The hatch is open. Is anyone listening?"