From asmirnov@kth.se Mon Mar 06 05:56:19 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!kth!asmirnov
From: asmirnov@kth.se (Anja Smirnov)
Newsgroups: comp.sys.m68k
Subject: Observation: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Mar06.055619.1440@kth.se>
Date: Mon, 06 Mar 1995 05:56:19 GMT
Organization: Royal Institute of Technology, Stockholm
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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.

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

-- 
=== Anja Smirnov ===
Dept of Electrical Engineering, Royal Institute of Technology, Stockholm
"We don't sign stars. We build them."

From erodriguez@mit.edu Wed Mar 08 02:25:19 1995
Path: ashpoly!cascade!bigsur!mit!erodriguez
From: erodriguez@mit.edu (Emi Rodríguez)
Newsgroups: comp.sys.m68k
Subject: Re: Observation: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Mar08.022519.9220@mit.edu>
Date: Wed, 08 Mar 1995 02:25:19 GMT
References: <1995Mar06.055619.1440@kth.se>
Organization: Massachusetts Institute of Technology
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In article <1995Mar06.055619.1440@kth.se>, asmirnov@kth.se (Anja Smirnov) 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.

PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985.

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

-- 
Emi Rodríguez | erodriguez@mit.edu
PGP Key fingerprint: 9F47 BA6B FA82 FBCC
"Keep the channels open."

From mvasiliev@unam.mx Fri Mar 10 01:59:19 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!unam!mvasiliev
From: mvasiliev@unam.mx (Mike Vasiliev)
Newsgroups: comp.sys.m68k
Subject: Re: Observation: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Mar10.015919.9265@unam.mx>
Date: Fri, 10 Mar 1995 01:59:19 GMT
References: <1995Mar06.055619.1440@kth.se>
Organization: Universidad Nacional Autónoma de México (DGSCA)
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In article <1995Mar06.055619.1440@kth.se>, asmirnov@kth.se (Anja Smirnov) 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.

-- 
=== Mike Vasiliev ===
Dept of Electrical Engineering, Universidad Nacional Autónoma de México (DGSCA)
"Row 14. No joke."