From lkuznetsov@u-tokyo.ac.jp Tue Jun 27 19:03:19 1995
Path: ashpoly!cascade!brgate!saturno!u-tokyo!lkuznetsov
From: lkuznetsov@u-tokyo.ac.jp (Lisa Kuznetsov)
Newsgroups: comp.sys.m68k
Subject: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Jun27.190319.5697@u-tokyo.ac.jp>
Date: Tue, 27 Jun 1995 19:03:19 GMT
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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.

Long live the Amiga. Try doing real-time subcarrier demodulation on a 386 running Windows 3.1 without dropping frames!

-- 
Lisa Kuznetsov | lkuznetsov@u-tokyo.ac.jp
PGP Key fingerprint: 0B3A 4706 1B9E 9DB4
"Keep the channels open."

From kmacdonald@clari.net Thu Jun 29 06:11:19 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!clari!kmacdonald
From: kmacdonald@clari.net (Karen MacDonald)
Newsgroups: comp.sys.m68k
Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Jun29.061119.8669@clari.net>
Date: Thu, 29 Jun 1995 06:11:19 GMT
References: <1995Jun27.190319.5697@u-tokyo.ac.jp>
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In article <1995Jun27.190319.5697@u-tokyo.ac.jp>, lkuznetsov@u-tokyo.ac.jp (Lisa Kuznetsov) writes:
> Wrote an Amiga assembly program that uses Paula's DMA audio channels to sample and track the Stardust subcarrier.

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

-- 
Karen MacDonald
Tape trading list upon request. SASE required for international mail.

From eduarte@earthlink.net Thu Jun 29 23:04:19 1995
Path: ashpoly!cascade!transat!eunet-de!hansebox!earthlink!eduarte
From: eduarte@earthlink.net (Elaine Duarte)
Newsgroups: comp.sys.m68k
Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Jun29.230419.3375@earthlink.net>
Date: Thu, 29 Jun 1995 23:04:19 GMT
References: <1995Jun27.190319.5697@u-tokyo.ac.jp>
Organization: EarthLink Network
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In article <1995Jun27.190319.5697@u-tokyo.ac.jp>, lkuznetsov@u-tokyo.ac.jp (Lisa Kuznetsov) 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.

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

-- 
Elaine Duarte | eduarte@earthlink.net
PGP Key fingerprint: D3CC F808 E1E1 9C71
"Keep the channels open."

From arodriguez@rwth-aachen.de Sat Jul 01 15:06:19 1995
Path: ashpoly!bigsur!pacrim!krgate!eunha!rwth-aachen!arodriguez
From: arodriguez@rwth-aachen.de (Amy Rodríguez)
Newsgroups: comp.sys.m68k
Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Jul01.150619.8968@rwth-aachen.de>
Date: Sat, 01 Jul 1995 15:06:19 GMT
References: <1995Jun27.190319.5697@u-tokyo.ac.jp> <1995Jun29.230419.3375@earthlink.net>
Organization: RWTH Aachen Informatik
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In article <1995Jun29.230419.3375@earthlink.net>, eduarte@earthlink.net (Elaine Duarte) 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!

-- 
Amy Rodríguez | arodriguez@rwth-aachen.de
PGP Key fingerprint: 7F14 0483 471D 6208
"Keep the channels open."