Av Dsp Faq

Subject: AV DSP Mini-FAQ v 1.01 From: bdenckla@husc7.harvard.edu (Benjamin Denckla) Date: 7 Dec 1993 17:43:17 GMT This document contains information relevant to the AV Macs, especially in relation to the use and programming of their DSP chip. It is the product of my own experience and many helpful responses I have received to posts I have made. I have taken slight liberties in editing responses, so what you see below are not always the exact words of the contributors to the FAQ. It is structured in the typical FAQ format of question and answer with the questions listed at the beginning. Please write me with any additions to or comments about this document. Ben Denckla Manager Harvard University Electronic Music Studio 1. Are modem/fax software and the GeoPort telecom adapter included? 2. Does audio output from the CD have an extra stage of A/D & D/A? 3. Is there an included utility which allows digital recording of part of an audio CD to an AIFF file? 4. Is there an included utility which will allow me to play/record 16- bit, 44.1KHz stereo AIFF files? 5. Is there any digital audio software available for the 660AV? 6. Is there any digital audio interfacing hardware available? (AES/EBU <--> DAV or AES/EBU <--> GeoPort) 7. What is needed to do DSP programming? 8. Where can I get example code for programs that use the AV's DSP? 9. Where can I get information about the DSP chip? 10. BugLite only supports 32-bit floating point data. Do I really want to use this data type? 11. Can I use Think C to write the Macintosh part of DSP applications? 12. What happens to DSP modules I have written when the hardware platform changes (to PowerPC, for instance)? .c.1. Are modem/fax software and the GeoPort telecom adapter included? The Geoport adapter must be bought separately for about $125. The adapter comes with the modem driver software and a complete, user-level fax software package. So you still need to own a separate modem communications program. Contrary to what some documentation says, you can do 14.4Kbaud, not just 9600 baud, with the modem. As an aside, I would like to point out that though the AV does speech generation and recognition right out of the box, it can't do modem/fax out of the box. Frankly I cannot believe that the number of users needing speech functions even approaches the number who need modem/fax. A clear case of "Gee-whiz! Bells & whistles! Screw the user!" marketing. Not that the $125 for the GeoPort even compares the the $995 for the ARTA toolkit (see below). .c.2. Does audio output from the CD have an extra stage of A/D & D/A? Yes. Evidence of this appears on p. 39 of Apple Developer Note #5, where the L & R outputs of the CD enter a block labelled "analog front end" before entering the Singer block. John Turpin <turpin@apple.com> confirms this and notes that the digital audio output from the CD is not compatible with the singer serial data bus. .c.3. Is there an included uti…