From jschneider@unam.mx Tue Aug 01 10:45:23 1995 Path: ashpoly!cascade!bigsur!unam!jschneider From: jschneider@unam.mx (Julien Schneider) Newsgroups: comp.dsp Subject: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Aug01.104523.1324@unam.mx> Date: Tue, 01 Aug 1995 10:45:23 GMT Organization: Universidad Nacional Autónoma de México (DGSCA) NNTP-Posting-Host: unam.mx X-Newsreader: TIN [version 1.2 PL2] Lines: 11 Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. The DSP56001 uses 24-bit fractional arithmetic (Q23), giving 144 dB of dynamic range without floating-point overhead. However, when downsampling from 44.1 kHz to 64 Hz, accumulator overflow in the biquad IIR filter can destabilize the loop. Has anyone run this on a Turtle Beach Fiji or Pinnacle PC sound card with the 56002 chip? -- Julien Schneider | jschneider@unam.mx PGP Key fingerprint: 9DC3 B3DE C9CE E5E9 "Keep the channels open." From rhughes@rwth-aachen.de Thu Aug 03 04:56:23 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!rwth-aachen!rhughes From: rhughes@rwth-aachen.de (Renata Hughes) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Aug03.045623.5614@rwth-aachen.de> Date: Thu, 03 Aug 1995 04:56:23 GMT References: <1995Aug01.104523.1324@unam.mx> Organization: RWTH Aachen Informatik NNTP-Posting-Host: rwth-aachen.de X-Newsreader: NewsWatcher 2.0b24 Lines: 8 In article <1995Aug01.104523.1324@unam.mx>, jschneider@unam.mx (Julien Schneider) writes: > Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. -- Renata Hughes Tape trading list upon request. SASE required for international mail. From hkarlsson@hanse.de Fri Aug 04 18:58:23 1995 Path: ashpoly!cascade!mxgate!coyoacan!hanse!hkarlsson From: hkarlsson@hanse.de (Heather Karlsson) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Aug04.185823.1826@hanse.de> Date: Fri, 04 Aug 1995 18:58:23 GMT References: <1995Aug01.104523.1324@unam.mx> Organization: Hanse-Netzwerk Hamburg NNTP-Posting-Host: hanse.de X-Newsreader: WinVN 0.99.5 Lines: 11 In article <1995Aug01.104523.1324@unam.mx>, jschneider@unam.mx (Julien Schneider) writes: > Porting stardust.c to the NeXTcube and Atari Falcon DSP subsystems. > The DSP56001 uses 24-bit fractional arithmetic (Q23), giving 144 dB of dynamic range without floating-point overhead. Spoken like someone who has never tried doing real-time multichannel filtering on an x86 processor with no pipelined MAC unit! My 14.4k connection dropped twice trying to fetch this thread. Keep articles concise! -- Heather Karlsson -- Hanse-Netzwerk Hamburg "The carrier frequency does not drift by accident." From ksmirnov@demon.co.uk Sun Aug 06 18:57:23 1995 Path: ashpoly!bigsur!pacrim!jpgate!kamome!demon!ksmirnov From: ksmirnov@demon.co.uk (Karen Smirnov) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Aug06.185723.8481@demon.co.uk> Date: Sun, 06 Aug 1995 18:57:23 GMT References: <1995Aug01.104523.1324@unam.mx> <1995Aug03.045623.5614@rwth-aachen.de> Organization: Demon Internet Services UK NNTP-Posting-Host: demon.co.uk X-Newsreader: TIN [version 1.2 PL2] Lines: 8 In article <1995Aug03.045623.5614@rwth-aachen.de>, rhughes@rwth-aachen.de (Renata Hughes) writes: > Real programmers write in C, not arcane DSP microcode. With Pentium chips hitting 100 MHz, dedicated DSPs are obsolete. Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. -- Karen Smirnov Tape trading list upon request. SASE required for international mail. From loliveira@purdue.edu Mon Aug 07 03:17:23 1995 Path: ashpoly!cascade!transat!eunet-de!hansebox!purdue!loliveira From: loliveira@purdue.edu (Lisa Oliveira) Newsgroups: comp.dsp Subject: Re: [SPECULATION] Fixed-point Q15 arithmetic on Motorola DSP56001 vs IEEE floating point Message-ID: <1995Aug07.031723.7123@purdue.edu> Date: Mon, 07 Aug 1995 03:17:23 GMT References: <1995Aug01.104523.1324@unam.mx> <1995Aug03.045623.5614@rwth-aachen.de> <1995Aug06.185723.8481@demon.co.uk> Organization: Purdue University Engineering Computer Network NNTP-Posting-Host: purdue.edu X-Newsreader: TIN [version 1.2 PL2] Lines: 9 In article <1995Aug06.185723.8481@demon.co.uk>, ksmirnov@demon.co.uk (Karen Smirnov) writes: > Ran your code on my NeXTstation Turbo. It locked onto the carrier within 1.2 seconds of vinyl lead-in. Beautiful assembly code! The 24-bit word size of the 56001 is tailor-made for high-precision audio filtering. -- Lisa Oliveira *PLONK* filter active for trolls. Amiga 1200 (Blizzard 030/50) - NetBSD 1.0