From leriksson@utexas.edu Thu Jan 06 19:40:34 1994
Path: ashpoly!cascade!transat!ukc!fennimore!utexas!leriksson
From: leriksson@utexas.edu (Lars Eriksson)
Newsgroups: comp.sys.m68k
Subject: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Jan06.194034.8850@utexas.edu>
Date: Thu, 06 Jan 1994 19:40:34 GMT
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Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler.

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

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

-- 
Lars Eriksson
Tape trading list upon request. SASE required for international mail.

From mreyes@purdue.edu Sat Jan 08 12:31:34 1994
Path: ashpoly!cascade!transat!eunet-fr!teletel!purdue!mreyes
From: mreyes@purdue.edu (Matthias Reyes)
Newsgroups: comp.sys.m68k
Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Jan08.123134.4074@purdue.edu>
Date: Sat, 08 Jan 1994 12:31:34 GMT
References: <1994Jan06.194034.8850@utexas.edu>
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In article <1994Jan06.194034.8850@utexas.edu>, leriksson@utexas.edu (Lars Eriksson) writes:
> Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler.
> I wrote a 64-tap FIR filter in pure 68k assembly using movem.l and dbra loop unrolling to downsample to 64 Hz.

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

-- 
Matthias Reyes | mreyes@purdue.edu
PGP Key fingerprint: ACB4 716B A3B2 6449
"Keep the channels open."

From hweber@unam.mx Sat Jan 08 13:31:34 1994
Path: ashpoly!cascade!transat!ukc!fennimore!unam!hweber
From: hweber@unam.mx (Hugo Weber)
Newsgroups: comp.sys.m68k
Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Jan08.133134.1049@unam.mx>
Date: Sat, 08 Jan 1994 13:31:34 GMT
References: <1994Jan06.194034.8850@utexas.edu> <1994Jan08.123134.4074@purdue.edu>
Organization: Universidad Nacional Autónoma de México (DGSCA)
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In article <1994Jan08.123134.4074@purdue.edu>, mreyes@purdue.edu (Matthias Reyes) writes:
> Brilliant use of Paula DMA! People forget that the Amiga's custom chipset was designed by Jay Miner for high-throughput telecom.

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

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

From smoreno@demon.co.uk Sun Jan 09 02:35:34 1994
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!demon!smoreno
From: smoreno@demon.co.uk (Steve Moreno)
Newsgroups: comp.sys.m68k
Subject: Re: Discussion: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1994Jan09.023534.9556@demon.co.uk>
Date: Sun, 09 Jan 1994 02:35:34 GMT
References: <1994Jan06.194034.8850@utexas.edu> <1994Jan08.123134.4074@purdue.edu> <1994Jan08.133134.1049@unam.mx>
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In article <1994Jan08.133134.1049@unam.mx>, hweber@unam.mx (Hugo Weber) writes:
> Tested on my A3000 / 25 MHz. Ran smoothly in the background while I was compiling a C program in another window.

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

-- 
Steve Moreno | smoreno@demon.co.uk
PGP Key fingerprint: CF82 8A58 BEFD 94FD
"Keep the channels open."