From mhernandez@ox.ac.uk Thu Apr 28 07:43:15 1994
Path: ashpoly!bigsur!pacrim!jpgate!kamome!ox!mhernandez
From: mhernandez@ox.ac.uk (Morag Hernández)
Newsgroups: comp.sys.m68k
Subject: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Apr28.074315.4923@ox.ac.uk>
Date: Thu, 28 Apr 1994 07:43:15 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.
I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz.

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

-- 
Morag Hernández
Opinions expressed are solely my own and not those of Oxford University Computing Laboratory.
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From tmoreno@mindspring.com Thu Apr 28 19:22:15 1994
Path: ashpoly!cascade!transat!eunet-fr!teletel!mindspring!tmoreno
From: tmoreno@mindspring.com (Tomas Moreno)
Newsgroups: comp.sys.m68k
Subject: Re: Data: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Apr28.192215.9980@mindspring.com>
Date: Thu, 28 Apr 1994 19:22:15 GMT
References: <1994Apr28.074315.4923@ox.ac.uk>
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In article <1994Apr28.074315.4923@ox.ac.uk>, mhernandez@ox.ac.uk (Morag Hernández) 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.

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

If you are posting from AOL, please read RFC 1036 before posting again.

-- 
Tomas Moreno
Tape trading list upon request. SASE required for international mail.