From bpopov@stanford.edu Mon Sep 16 19:26:06 1996
Path: ashpoly!cascade!bigsur!stanford!bpopov
From: bpopov@stanford.edu (Bill Popov)
Newsgroups: comp.sys.m68k
Subject: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1996Sep16.192606.5209@stanford.edu>
Date: Mon, 16 Sep 1996 19:26:06 GMT
Organization: Stanford University Computer Systems Lab
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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.
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.

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

-- 
Bill Popov -- Stanford University Computer Systems Lab
"Hardware is temporary. The signal survives."

From tsanchez@cmu.edu Mon Sep 16 21:00:06 1996
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!cmu!tsanchez
From: tsanchez@cmu.edu (Tyler Sánchez)
Newsgroups: comp.sys.m68k
Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1996Sep16.210006.7358@cmu.edu>
Date: Mon, 16 Sep 1996 21:00:06 GMT
References: <1996Sep16.192606.5209@stanford.edu>
Organization: Carnegie Mellon University School of CS
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In article <1996Sep16.192606.5209@stanford.edu>, bpopov@stanford.edu (Bill Popov) writes:
> Testing custom audio input routines on an Amiga 1200 with a standard parallel-port sampler.

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

-- 
Tyler Sánchez
Opinions expressed are solely my own and not those of Carnegie Mellon University School of CS.
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From mramirez@kth.se Wed Sep 18 14:59:06 1996
Path: ashpoly!cascade!transat!eunet-fi!relcom!kiae!kth!mramirez
From: mramirez@kth.se (Matthias Ramírez)
Newsgroups: comp.sys.m68k
Subject: Re: Question: Real-time 14.2 Hz demodulation on Amiga Paula audio DMA
Message-ID: <1996Sep18.145906.7539@kth.se>
Date: Wed, 18 Sep 1996 14:59:06 GMT
References: <1996Sep16.192606.5209@stanford.edu> <1996Sep16.210006.7358@cmu.edu>
Organization: Royal Institute of Technology, Stockholm
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In article <1996Sep16.210006.7358@cmu.edu>, tsanchez@cmu.edu (Tyler Sánchez) writes:
> PC users spend $3,000 on Sound Blasters and Pentium chips and still can't do what a $500 Amiga was doing in 1985.

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

-- 
Matthias Ramírez -- Royal Institute of Technology, Stockholm
"A soul is not exclusive to biology."