Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!uunet!seismo!mcvax!enea!tut!santra!news From: news@santra.UUCP (news) Newsgroups: sci.electronics,rec.music.synth Subject: Re: DCO's revisited - an inquiry into hardware implementation Message-ID: <6641@santra.UUCP> Date: Mon, 13-Jul-87 08:23:39 EDT Article-I.D.: santra.6641 Posted: Mon Jul 13 08:23:39 1987 Date-Received: Tue, 14-Jul-87 06:36:38 EDT References: <235@cogent.UUCP> <999@vaxb.calgary.UUCP> <678@elmgate.UUCP> <1948@oliveb.UUCP> Reply-To: jku@kolvi.UUCP (Juha Kuusama) Organization: Helsinki University of Technology, Finland Lines: 57 Keywords: now for the real work... Xref: mnetor sci.electronics:953 rec.music.synth:1077 In article <1948@oliveb.UUCP> prs@oliven.UUCP (Philip Stephens) writes: > >My guess for fetch one of several 32 bit indexes from on-chip ram, add a >16 bit increment, update index, use result as indirect address, and >output fetched word to an I/O port (ie, cycles per voice): > >load word to low accumulator 1 >load word to high accumulator 1 >add word to low accumulator 1 >store word from low accumulator 1 >store word from high accumulator 1 >load from offchip, with indirect addr 1?? >output to port 2 > >total 8 (or 9?) > ie, less than 2 microseconds with the 320C10, < 1 with 20 or C25! >(looks like can probably do about 12 voices per C10 at 40 Khz, or more >like 8 voices per chip if also do envelopes. Can easily afford two chips, >or several. Additional chip(s) for reverb, flanging, etc). > The calculations above are obviously in the right magnitude. I quess you want to do some filtering, too, and... I quess it might be easier to have one or two complete voices on a chip and the one for combining all together, with some effects, maybe, than to have long chain of chips. The processing power doesn't increase, of course, but it may well be easier to control and program in paraller configuration. This way you will get more easily different sounds from different voices. >I'm just speculating from the data sheet; I hope someone else can give >more practical feedback on this or any other DSP chip family (including >Motorola, hint hint. And I've sent for OKI info; anyone else already Other names are National (32something), NEC, AT&T etc. Basically no real differences in performance (given the same clock speed), at least in this application. Texas has been around long and has support available. (Compilers (for non-real-time stuff), evaluation boards, application notes ...) If you start from beginning, Texas is a good choice (as could be many others, too; no flames. please.) >Is there enough interest for a DSP or C10 group, or rather, a mailing list? > > - Phil prs@oliveb.UUCP (Phil Stephens) A few years ago there was some discussion for x.x.x.DSP, but no newsgroup. If a mailing list will be set up, include me. The DSP-based music syntheziser sounds as a very intresting project. I volunteer to do some work for it, if a team can be assembled. I have quite a good resources, wich I can use for hobby projects in my spare time. Let's go for it! Juha Kuusama, jku@kolvi ( ...!mcvax!tut!kolvi!jku ) Helsinki University of Technology, Otakaari 5 I, 02150 Espoo, Finland