Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!lll-winken!ames!pasteur!ucbvax!decwrl!shelby!polya!ali From: ali@polya.Stanford.EDU (Ali T. Ozer) Newsgroups: comp.sys.next Subject: Re: Real Time and Mach Message-ID: <7736@polya.Stanford.EDU> Date: 15 Mar 89 21:28:49 GMT References: <2897@eos.UUCP> Sender: Ali T. Ozer Reply-To: aozer@NeXT.com (Ali Ozer) Organization: . Lines: 22 In article <2897@eos.UUCP> phil@eos.UUCP (Phil Stone) writes: >Thanks for the info on sampling rates and the NeXT, everybody. As I >thought, the maximum stand-alone sampling rate is 44.1 Khz. Ali Ozer >mentioned a company that has announced an add-on that will allow >88.2 Khz in monoaural. I will look into this for details. Some more info: The maximum data rate into the DSP is apparently 2.5 Mbits/sec, synchronous. Starting from this info and assuming a 16-bit sampler, it seems like you should be able to get a maximum sampling rate of about 156 kHz (2.5 Mbits/sec / 16 bits/sample). The Digital Ears info sheet I have indicates that it can do 88.2 khz (using 16-bit samples). At that sampling rate, you get about 11 microseconds per sample. The DSP runs at 25 MHz, and most instructions are 2 clocks long; thus, in 11 microseconds, you can execute about 130 instructions and do whatever you want to that data... Please feel free to let me know if the above seems incorrect. Phil Stone: If you talk to Metaresearch, you might want to confirm the above... Ali Ozer, NeXT Developer Support