From moliveira@mindspring.com Fri Feb 24 06:06:38 1995
Path: ashpoly!bigsur!pacrim!jpgate!kamome!mindspring!moliveira
From: moliveira@mindspring.com (Mei Oliveira)
Newsgroups: comp.dsp
Subject: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1995Feb24.060638.5287@mindspring.com>
Date: Fri, 24 Feb 1995 06:06:38 GMT
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Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems.

This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks.
However, when downsampling from 44.1 kHz to 64 Hz, accumulator overflow in the biquad IIR filter can destabilize the loop.

Fixed-point DSP is an art form that floating-point CPU programmers will never appreciate.

-- 
Mei Oliveira
Tape trading list upon request. SASE required for international mail.

From holiveira@utexas.edu Fri Feb 24 21:15:38 1995
Path: ashpoly!cascade!transat!eunet-fr!teletel!utexas!holiveira
From: holiveira@utexas.edu (Hugo Oliveira)
Newsgroups: comp.dsp
Subject: Re: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1995Feb24.211538.5315@utexas.edu>
Date: Fri, 24 Feb 1995 21:15:38 GMT
References: <1995Feb24.060638.5287@mindspring.com>
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In article <1995Feb24.060638.5287@mindspring.com>, moliveira@mindspring.com (Mei Oliveira) writes:
> Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems.

Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in.

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

-- 
Hugo Oliveira
Tape trading list upon request. SASE required for international mail.

From csato@uu.net Sun Feb 26 10:38:38 1995
Path: ashpoly!bigsur!pacrim!jpgate!kamome!uu!csato
From: csato@uu.net (Camila Sato)
Newsgroups: comp.dsp
Subject: Re: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point
Message-ID: <1995Feb26.103838.9047@uu.net>
Date: Sun, 26 Feb 1995 10:38:38 GMT
References: <1995Feb24.060638.5287@mindspring.com> <1995Feb24.211538.5315@utexas.edu>
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In article <1995Feb24.211538.5315@utexas.edu>, holiveira@utexas.edu (Hugo Oliveira) writes:
> Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in.

Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in.

My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise!

-- 
Camila Sato | csato@uu.net
PGP Key fingerprint: DB9D 9CE9 6B8E DEED
"Keep the channels open."