Xref: utzoo rec.music.synth:4950 comp.sys.next:133
Path: utzoo!utgpu!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!agate!bionet!apple!epimass!jbuck
From: jbuck@epimass.EPI.COM (Joe Buck)
Newsgroups: rec.music.synth,comp.sys.next
Subject: Re: NeXT!
Message-ID: <2587@epimass.EPI.COM>
Date: 21 Oct 88 17:35:43 GMT
References: <881019-085756-6643@Xerox> <1127@leah.Albany.Edu> <2881@sugar.uu.net>
Reply-To: jbuck@epimass.EPI.COM (Joe Buck)
Organization: Entropic Processing, Inc., Cupertino, CA
Lines: 27

In article <2881@sugar.uu.net> peter@sugar.uu.net (Peter da Silva) writes:
>[ For the comp.sys.next people, they've been talking about using NeXT as
>  a realtime music synthesiser, based on the DSP chip... ]
>
>One thing to consider. The NeXT machine is running UNIX (well, BSD under
>Mach), which is not a realtime operating system. A synth is a pretty hard-
>realtime environment.

The synthesizer wouldn't run on the 68030 (though configuration of the
synthesizer would), but rather on the 56001, which is designed for
real-time digital signal processing.  The thing has DMA channels which
probably can be configured to take data from the 56001 to D/A's
without intervention from the 68030 at all.

>What do you suppose will be the likely effect of cron running sync at random
>times? I suppose you'd remember not to let cron start a news-unbatch during a
>drum solo, but I'd still be leary of it. We don't use UNIX for realtime for
>good reasons.

Depends.  If you were having the system synthesize a pre-composed
piece of music, you could structure things so the 56000 keeps things
going and the 68030 just feeds commands to a queue -- no interruption
at all.  If you're using keyboard input, you might have slow response
sometimes when the sync hits.
-- 
- Joe Buck, card-carrying ACLU liberal
	jbuck@epimass.epi.com, or uunet!epimass.epi.com!jbuck,
	or jbuck%epimass.epi.com@uunet.uu.net for old Arpa sites