From sivanov@uu.net Tue May 24 19:49:37 1994
Path: ashpoly!cascade!brgate!saturno!uu!sivanov
From: sivanov@uu.net (Sergei Ivanov)
Newsgroups: comp.sys.m68k
Subject: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994May24.194937.1544@uu.net>
Date: Tue, 24 May 1994 19:49:37 GMT
Organization: UUNET Technologies, Falls Church VA
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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?

-- 
=== Sergei Ivanov ===
Dept of Electrical Engineering, UUNET Technologies, Falls Church VA
"When every node is whole, the channel opens."

From rvasiliev@kiae.su Thu May 26 14:50:37 1994
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!kiae!rvasiliev
From: rvasiliev@kiae.su (Renata Vasiliev)
Newsgroups: comp.sys.m68k
Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994May26.145037.8439@kiae.su>
Date: Thu, 26 May 1994 14:50:37 GMT
References: <1994May24.194937.1544@uu.net>
Organization: Kurchatov Institute of Atomic Energy, Moscow
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In article <1994May24.194937.1544@uu.net>, sivanov@uu.net (Sergei Ivanov) writes:
> Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler.

Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos!

Unsubscribe me from this list! (Wait, this is Usenet, never mind).

-- 
Renata Vasiliev | rvasiliev@kiae.su
PGP Key fingerprint: 0893 7C4B F0A0 A9ED
"Keep the channels open."

From adubois@kth.se Thu May 26 17:54:37 1994
Path: ashpoly!cascade!transat!eunet-de!hansebox!kth!adubois
From: adubois@kth.se (Andrei Dubois)
Newsgroups: comp.sys.m68k
Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994May26.175437.3486@kth.se>
Date: Thu, 26 May 1994 17:54:37 GMT
References: <1994May24.194937.1544@uu.net> <1994May26.145037.8439@kiae.su>
Organization: Royal Institute of Technology, Stockholm
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In article <1994May26.145037.8439@kiae.su>, rvasiliev@kiae.su (Renata Vasiliev) writes:
> Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos!

Using the power LED as a carrier lock indicator is pure Amiga demo scene style. Kudos!

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

From tivanov@cmu.edu Fri May 27 05:25:37 1994
Path: ashpoly!cascade!transat!eunet-fr!teletel!cmu!tivanov
From: tivanov@cmu.edu (Thiago Ivanov)
Newsgroups: comp.sys.m68k
Subject: Re: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994May27.052537.3895@cmu.edu>
Date: Fri, 27 May 1994 05:25:37 GMT
References: <1994May24.194937.1544@uu.net>
Organization: Carnegie Mellon University School of CS
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In article <1994May24.194937.1544@uu.net>, sivanov@uu.net (Sergei Ivanov) writes:
> Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler.

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

-- 
Thiago Ivanov
Tape trading list upon request. SASE required for international mail.