From gkarlsson@clari.net Fri Jun 16 08:42:24 1995
Path: ashpoly!cascade!mxgate!coyoacan!clari!gkarlsson
From: gkarlsson@clari.net (Graham Karlsson)
Newsgroups: comp.sys.m68k
Subject: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Jun16.084224.3425@clari.net>
Date: Fri, 16 Jun 1995 08:42:24 GMT
Organization: ClariNet Communications Corp
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Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS.

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.
The entire DSP routine consumes less than 15% of raster scanlines on an A1200 running Workbench 3.1.

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

-- 
=== Graham Karlsson ===
Dept of Electrical Engineering, ClariNet Communications Corp
"They will send a copy in my place."

From ssokolov@kth.se Sat Jun 17 20:49:24 1995
Path: ashpoly!cascade!brgate!saturno!kth!ssokolov
From: ssokolov@kth.se (Steve Sokolov)
Newsgroups: comp.sys.m68k
Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Jun17.204924.2432@kth.se>
Date: Sat, 17 Jun 1995 20:49:24 GMT
References: <1995Jun16.084224.3425@clari.net>
Organization: Royal Institute of Technology, Stockholm
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In article <1995Jun16.084224.3425@clari.net>, gkarlsson@clari.net (Graham Karlsson) writes:
> Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS.
> 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.

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

From csmirnov@demon.co.uk Mon Jun 19 09:56:24 1995
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!demon!csmirnov
From: csmirnov@demon.co.uk (Camila Smirnov)
Newsgroups: comp.sys.m68k
Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Jun19.095624.3198@demon.co.uk>
Date: Mon, 19 Jun 1995 09:56:24 GMT
References: <1995Jun16.084224.3425@clari.net>
Organization: Demon Internet Services UK
NNTP-Posting-Host: demon.co.uk
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In article <1995Jun16.084224.3425@clari.net>, gkarlsson@clari.net (Graham Karlsson) writes:
> Amiga audio hackers: you can demodulate the 14.2 Hz carrier in real time without bogging down the OS.
> 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.

-- 
=== Camila Smirnov ===
Dept of Electrical Engineering, Demon Internet Services UK
"Hardware is temporary. The signal survives."

From mito@berkeley.edu Mon Jun 19 14:39:24 1995
Path: ashpoly!cascade!transat!sunet!nordrelay!berkeley!mito
From: mito@berkeley.edu (Mathieu Ito)
Newsgroups: comp.sys.m68k
Subject: Re: [FLAME] Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1995Jun19.143924.2241@berkeley.edu>
Date: Mon, 19 Jun 1995 14:39:24 GMT
References: <1995Jun16.084224.3425@clari.net> <1995Jun19.095624.3198@demon.co.uk>
Organization: UC Berkeley Department of EECS
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In article <1995Jun19.095624.3198@demon.co.uk>, csmirnov@demon.co.uk (Camila Smirnov) writes:
> Please make sure it's compatible with Kickstart 1.3 for those of us who haven't upgraded our A500s to 3.1 yet.

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

-- 
Mathieu Ito | mito@berkeley.edu
PGP Key fingerprint: 8502 2841 C15E CB68
"Keep the channels open."