From bnovak@purdue.edu Wed Mar 15 00:15:57 1995 Path: ashpoly!cascade!brgate!saturno!purdue!bnovak From: bnovak@purdue.edu (Bill Novak) Newsgroups: comp.dsp Subject: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar15.001557.7716@purdue.edu> Date: Wed, 15 Mar 1995 00:15:57 GMT Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 10 Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. However, when downsampling from 44.1 kHz to 64 Hz, accumulator overflow in the biquad IIR filter can destabilize the loop. This leaves over 95% of the DSP56001's 16.5 MIPS available for other audio tasks. Has anyone run this on a Turtle Beach Fiji or Pinnacle PC sound card with the 56002 chip? -- Bill Novak Tape trading list upon request. SASE required for international mail. From ntanaka@clari.net Fri Mar 17 03:19:57 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!clari!ntanaka From: ntanaka@clari.net (Nadia Tanaka) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar17.031957.6380@clari.net> Date: Fri, 17 Mar 1995 03:19:57 GMT References: <1995Mar15.001557.7716@purdue.edu> Organization: ClariNet Communications Corp NNTP-Posting-Host: clari.net X-Newsreader: Netscape 1.1N Lines: 9 In article <1995Mar15.001557.7716@purdue.edu>, bnovak@purdue.edu (Bill Novak) 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. -- Nadia Tanaka *PLONK* filter active for trolls. PC-9821Ap2 (NEC) - NetBSD 1.0 From rchoi@u-tokyo.ac.jp Fri Mar 17 05:31:57 1995 Path: ashpoly!cascade!bigsur!u-tokyo!rchoi From: rchoi@u-tokyo.ac.jp (Rodrigo Choi) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar17.053157.9286@u-tokyo.ac.jp> Date: Fri, 17 Mar 1995 05:31:57 GMT References: <1995Mar15.001557.7716@purdue.edu> <1995Mar17.031957.6380@clari.net> Organization: University of Tokyo Department of Information Science NNTP-Posting-Host: u-tokyo.ac.jp X-Newsreader: NewsWatcher 2.0b24 Lines: 11 In article <1995Mar17.031957.6380@clari.net>, ntanaka@clari.net (Nadia Tanaka) writes: > Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. Top-posters will be placed in my ~/.killfile without notice. -- Rodrigo Choi Opinions expressed are solely my own and not those of University of Tokyo Department of Information Science. ------------------------------------------------------------ From schoi@panix.com Fri Mar 17 15:09:57 1995 Path: ashpoly!cascade!transat!sunet!nordrelay!panix!schoi From: schoi@panix.com (Sergei Choi) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar17.150957.8476@panix.com> Date: Fri, 17 Mar 1995 15:09:57 GMT References: <1995Mar15.001557.7716@purdue.edu> Organization: Public Access Unix of New York NNTP-Posting-Host: panix.com X-Newsreader: WinVN 0.99.5 Lines: 9 In article <1995Mar15.001557.7716@purdue.edu>, bnovak@purdue.edu (Bill Novak) writes: > Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. > However, when downsampling from 44.1 kHz to 64 Hz, accumulator overflow in the biquad IIR filter can destabilize the loop. Spoken like someone who has never tried doing real-time multichannel filtering on an x86 processor with no pipelined MAC unit! -- Sergei Choi Tape trading list upon request. SASE required for international mail. From asilva@unam.mx Sun Mar 19 10:43:57 1995 Path: ashpoly!cascade!mxgate!coyoacan!unam!asilva From: asilva@unam.mx (Astrid Silva) Newsgroups: comp.dsp Subject: Re: Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Mar19.104357.3912@unam.mx> Date: Sun, 19 Mar 1995 10:43:57 GMT References: <1995Mar15.001557.7716@purdue.edu> Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: Netscape 1.1N Lines: 10 In article <1995Mar15.001557.7716@purdue.edu>, bnovak@purdue.edu (Bill Novak) writes: > Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. > However, when downsampling from 44.1 kHz to 64 Hz, accumulator overflow in the biquad IIR filter can destabilize the loop. Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. -- Astrid Silva Opinions expressed are solely my own and not those of Universidad Nacional Autónoma de México (DGSCA). ------------------------------------------------------------